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1.
Int J Biol Macromol ; 267(Pt 1): 131573, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38614188

RESUMO

DNA, vital for biological processes, encodes hereditary data for protein synthesis, shaping cell structure and function. Since revealing its structure, DNA has become a target for various therapeutically vital molecules, spanning antidiabetic to anticancer drugs. These agents engage with DNA-associated proteins, DNA-RNA hybrids, or bind directly to the DNA helix, triggering diverse downstream effects. These interactions disrupt vital enzymes and proteins essential for maintaining cell structure and function. Analysing drug-DNA interactions has significantly advanced our understanding of drug mechanisms. Glipizide, an antidiabetic drug, is known to cause DNA damage in adipocytes. However, its extract mechanism of DNA interaction is unknown. This study delves into the interaction between glipizide and DNA utilizing various biophysical tools and computational technique to gain insights into the interaction mechanism. Analysis of UV-visible and fluorescence data reveals the formation of complex between DNA and glipizide. The binding affinity of glipizide to DNA was of moderate strength. Examination of thermodynamic parameters at different temperatures suggests that the binding was entropically spontaneous and energetically favourable. Various experiments such as thermal melting assays, viscosity measurement, and dye displacement assays confirmed the minor grove nature of binding of glipizide with DNA. Molecular dynamics studies confirmed the glipizide forms stable complex with DNA when simulated by mimicking the physiological conditions. The binding was mainly favoured by hydrogen bonds and glipizide slightly reduced nucleotide fluctuations of DNA. The study deciphers the mechanism of interaction of glipizide with DNA at molecular levels.


Assuntos
DNA , Glipizida , Simulação de Dinâmica Molecular , Termodinâmica , Glipizida/química , Glipizida/farmacologia , DNA/química , DNA/metabolismo , Biologia Computacional/métodos , Simulação de Acoplamento Molecular , Conformação de Ácido Nucleico , Hipoglicemiantes/química , Hipoglicemiantes/farmacologia
2.
Drug Res (Stuttg) ; 74(3): 123-132, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38408478

RESUMO

Glipizide is an oral glucose-lowering medication that is beneficial for the treatment of type 2 diabetes. This study compiles exhaustively all accessible information on glipizide, from preclinical to clinical studies. Glipizide may be used in concert with TRAIL to treat cancer cells; in vitro studies have shown that it suppresses angiogenesis and vasculogenesis while shielding cells from glycation-induced damage. Anticonvulsant effects and modifications in the pharmacokinetics of other medications, such as Divalproex Sodium, were seen in glipizide in vivo experiments. Propranolol amplifies glipizide's hypoglycemic effect briefly in normal animals but consistently enhances it in diabetic ones. In the treatment of cancer and neurodegenerative poly(Q) illnesses, glipizide has demonstrated to offer potential therapeutic advantages. It is ineffective in preventing DENA-induced liver cancer and may cause DNA damage over time. The way glipizide interacts with genetic variants may increase the risk of hypoglycemia. Combining Syzygium cumini and ARBE to glipizide may enhance glycemic and lipid control in type 2 diabetes. Individuals with coronary artery disease who take glipizide or glyburide have an increased risk of death. The risk of muscular responses and acute pancreatitis is minimal when glipizide and dulaglutide are combined. In conclusion, glipizide has shown promising therapeutic efficacy across a variety of disorders.


Assuntos
Diabetes Mellitus Tipo 2 , Pancreatite , Humanos , Glipizida/efeitos adversos , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/induzido quimicamente , Doença Aguda , Glicemia , Pancreatite/induzido quimicamente , Pancreatite/tratamento farmacológico
3.
PLoS One ; 19(2): e0297467, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38394326

RESUMO

Glipizide, a poor water-soluble drug belongs to BCS class II. The proposed work aimed to enhance the solubility of glipizide by preparing solid dispersions, using polyvinyl pyrrolidone (PVP) and polyethylene glycol (PEG). Solvent evaporation method was used for the preparation of glipizide solid dispersions. Solid dispersions were prepared in four different drug-to-polymer ratios i.e. 1:1, 1:2, 1:3 and 1:4. Mainly effect of three polymers (PVP K30, PVP K90 and PEG 6000) was evaluated on the solubility and dissolution of glipizide. The in-vitro dissolution of all prepared formulations was performed under pH 6.8 at 37°C using USP type II apparatus. In-vitro dissolution results revealed that the formulations having high concentrations of the polymer showed enhanced solubility. Enhancements in the solubility and rate of dissolution of the drug were noted in solid dispersion formulations compared to the physical blends and pure drug. Solid dispersions containing polyvinyl pyrrolidone exhibited a more favorable pattern of drug release compared to the corresponding solid dispersions with PEG. An increase in the maximum solubility of the drug within the solid dispersion systems was observed in all instances. Two solid dispersion formulations were optimized and formulated into immediate-release tablets, which passed all the pharmacopoeial and non-pharmacopoeial tests. Fourier transformed Infrared (FTIR) spectroscopy X-ray diffraction (XRD) and Differential scanning calorimetry (DSC) were used to indicate drug: polymer interactions in solid state. Analysis of the solid dispersion samples through characterization tests indicated the compatibility between the drug and the polymer.


Assuntos
Glipizida , Polivinil , Solubilidade , Polímeros/química , Polietilenoglicóis/química , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Povidona/química , Difração de Raios X , Varredura Diferencial de Calorimetria
4.
Inflammation ; 46(5): 1917-1931, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37289398

RESUMO

New consensus indicates type 2 diabetes mellitus (T2DM) and periodontitis as comorbidity and may share common pathways of disease progression. Sulfonylureas have been reported to improve the periodontal status in periodontitis patients. Glipizide, a sulfonylurea widely used in the treatment of T2DM, has also been reported to inhibit inflammation and angiogenesis. The effect of glipizide on the pathogenicity of periodontitis, however, has not been studied. We developed ligature-induced periodontitis in mice and treated them with different concentrations of glipizide and then analyzed the level of periodontal tissue inflammation, alveolar bone resorption, and osteoclast differentiation. Inflammatory cell infiltration and angiogenesis were analyzed using immunohistochemistry, RT-qPCR, and ELISA. Transwell assay and Western bolt analyzed macrophage migration and polarization. 16S rRNA sequencing analyzed the effect of glipizide on the oral microbial flora. mRNA sequencing of bone marrow-derived macrophages (BMMs) stimulated by P. gingivalis lipopolysaccharide (Pg-LPS) after treatment with glipizide was analyzed. Glipizide decreases alveolar bone resorption, periodontal tissue degradation, and the number of osteoclasts in periodontal tissue affected by periodontitis (PAPT). Glipizide-treated periodontitis mice showed reduced micro-vessel density and leukocyte/macrophage infiltration in PAPT. Glipizide significantly inhibited osteoclast differentiation in vitro experiments. Glipizide treatment did not affect the oral microbiome of periodontitis mice. mRNA sequencing and KEGG analysis showed that glipizide activated PI3K/AKT signaling in LPS-stimulated BMMs. Glipizide inhibited the LPS-induced migration of BMMs but promoted M2/M1 macrophage ratio in LPS-induced BMMs via activation of PI3K/AKT signaling. In conclusion, glipizide inhibits angiogenesis, macrophage inflammatory phenotype, and osteoclastogenesis to alleviate periodontitis pathogenicity suggesting its' possible application in the treatment of periodontitis and diabetes comorbidity.


Assuntos
Perda do Osso Alveolar , Diabetes Mellitus Tipo 2 , Periodontite , Humanos , Camundongos , Animais , Osteogênese , Glipizida/metabolismo , Glipizida/farmacologia , Diabetes Mellitus Tipo 2/metabolismo , Lipopolissacarídeos/farmacologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , RNA Ribossômico 16S/metabolismo , Virulência , Periodontite/tratamento farmacológico , Periodontite/metabolismo , Osteoclastos/metabolismo , Inflamação/metabolismo , Macrófagos/metabolismo , Perda do Osso Alveolar/tratamento farmacológico , Perda do Osso Alveolar/prevenção & controle , Perda do Osso Alveolar/metabolismo , RNA Mensageiro/metabolismo
5.
J Pharm Sci ; 112(5): 1268-1276, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36822274

RESUMO

Metformin and its combinations are widely used to treat type 2 diabetes. The drugs commonly used in combination with Metformin are Glipizide, Glibenclamide, Gliclazide, Evogliptin, and Glimepiride. Combination therapy is preferred over monotherapy of Metformin in most diabetics. About eighteen pharmaceutical manufacturers have lately recalled metformin formulation batches from the U.S. market due to N-nitrosodimethylamine (NDMA) impurities based on the food and drug administration (USFDA) guideline "Control of Nitrosamine in Human Drugs." European Medicines Agency (EMA) and Health Canada have also established guidelines for nitrosamine impurities. Nitrosamines are well-known mutagenic impurities and probable human carcinogens found in pharmaceutical formulations. Thus, global regulatory agencies require pharmaceutical and formulation manufacturers to complete risk assessments for nitrosamine impurities for patient safety. Therefore, drug manufacturers must develop analytical techniques for monitoring trace nitrosamine impurities. Quantifying nitrosamine impurities in formulations requires modern equipment like LC-MS/MS and great intellect. The present study intends to give a single pre-packaged LC-MS/MS method parameters, including liquid chromatography and triple quadrupole mass spectrometer configuration. This method could quantify eight nitrosamine impurities from five different Metformin combinations (Metformin with Glipizide, Glibenclamide, Gliclazide, Evogliptin, and Glimepiride). The atmospheric pressure chemical ionisation (APCI) was used as an ionisation source, and the mass spectrometer was set to multiple reaction monitoring (MRM) mode for all eight nitrosamine impurities. A unified pre-packaged analytical setup allows analytical chemists to develop a reliable, sensitive, robust, and precise method for quantifying eight nitrosamine impurities from five different Metformin formulations of varying manufacturers. This analytical method saves time, money, and the environment using fewer pharmaceutical chemicals.


Assuntos
Diabetes Mellitus Tipo 2 , Gliclazida , Metformina , Nitrosaminas , Humanos , Glipizida , Glibureto , Metformina/uso terapêutico , Gliclazida/uso terapêutico , Cromatografia Líquida de Alta Pressão/métodos , Diabetes Mellitus Tipo 2/tratamento farmacológico , Cromatografia Líquida/métodos , Nitrosaminas/uso terapêutico , Espectrometria de Massas em Tandem/métodos , Preparações Farmacêuticas/química
6.
Am J Physiol Endocrinol Metab ; 323(2): E123-E132, 2022 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-35723225

RESUMO

Fibroblast growth factor 21 (FGF21) is increased acutely by carbohydrate ingestion and is elevated in patients with type 2 diabetes (T2D). However, the physiological significance of increased FGF21 in humans remains largely unknown. We examined whether FGF21 contributed to the metabolic improvements observed following treatment of patients with T2D with either triple (metformin/pioglitazone/exenatide) or conventional (metformin/insulin/glipizide) therapy for 3 yr. Forty-six patients with T2D were randomized to receive either triple or conventional therapy to maintain HbA1c < 6.5%. A 2-h 75-g oral glucose tolerance test (OGTT) was performed at baseline and following 3 years of treatment to assess glucose tolerance, insulin sensitivity, and ß-cell function. Plasma total and bioactive FGF21 levels were quantitated before and during the OGTT at both visits. Patients in both treatment arms experienced significant improvements in glucose control, but insulin sensitivity and ß-cell function were markedly increased after triple therapy. At baseline, FGF21 levels were regulated acutely during the OGTT in both groups. After treatment, fasting total and bioactive FGF21 levels were significantly reduced in patients receiving triple therapy, but there was a relative increase in the proportion of bioactive FGF21 compared with that observed in conventionally treated subjects. Relative to baseline studies, triple therapy treatment also significantly modified FGF21 levels in response to a glucose load. These changes in circulating FGF21 were correlated with markers of improved glucose control and insulin sensitivity. Alterations in the plasma FGF21 profile may contribute to the beneficial metabolic effects of pioglitazone and exenatide in human patients with T2D.NEW & NOTEWORTHY In patients with T2D treated with a combination of metformin/pioglitazone/exenatide (triple therapy), we observed reduced total and bioactive plasma FGF21 levels and a relative increase in the proportion of circulating bioactive FGF21 compared with that in patients treated with metformin and sequential addition of glipizide and basal insulin glargine (conventional therapy). These data suggest that FGF21 may contribute, at least in part, to the glycemic benefits observed following combination therapy in patients with T2D.


Assuntos
Diabetes Mellitus Tipo 2 , Resistência à Insulina , Metformina , Tiazolidinedionas , Glicemia/metabolismo , Diabetes Mellitus Tipo 2/tratamento farmacológico , Exenatida , Fatores de Crescimento de Fibroblastos , Glipizida , Hemoglobinas Glicadas/metabolismo , Humanos , Hipoglicemiantes/uso terapêutico , Metformina/uso terapêutico , Peptídeos , Pioglitazona , Peçonhas
7.
J Biomol Struct Dyn ; 40(24): 13747-13758, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34709124

RESUMO

COVID-19 caused by SARS-CoV-2 has emerged as a potential threat to human life, especially to people suffering from chronic diseases. In this study, we investigated the ability of selected FDA-approved drugs to inhibit TACE (tumor necrosis factor α converting enzyme), which is responsible for the shedding of membrane-bound ACE2 (angiotensin-converting enzyme2) receptors into soluble ACE2. The inhibition of TACE would lead to an increased population of membrane-bound ACE2, which would facilitate ACE2-Spike protein interaction and viral entry. A total of 50 drugs prescribed in treating various chronic diseases in Saudi Arabia were screened by performing molecular docking using AutoDock4.2. Based on docking energy (≤ -9.00 kcal mol-1), four drugs (Celecoxib, Glipizide, Lapatinib, and Sitagliptin) were identified as potential inhibitors of TACE, with binding affinities up to 106-107 M-1. Analysis of the molecular docking suggests that these drugs were bound to TACE's catalytic domain and interact with the key residues such as His405, Glu406, and His415, which are involved in active site Zn2+ ion chelation. Molecular dynamics simulation was performed to confirm the stability of TACE-drugs complexes. RMSD (root mean square deviation), RMSF (root mean square fluctuation), Rg (radius of gyration), and SASA (solvent accessible surface area) were within the acceptable limits. Free energy calculations using Prime-MM/GBSA suggest that Celecoxib formed the most stable complex with TACE, followed by Glipizide, Sitagliptin, and Lapatinib. The finding of this study suggests a mechanism for drugs to aggravate SARS-CoV-2 infection and hence high mortality in patients suffering from chronic diseases.Communicated by Ramaswamy H. Sarma.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , Celecoxib/farmacologia , Glipizida , Lapatinib , Fosfato de Sitagliptina , Enzima de Conversão de Angiotensina 2 , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Ligação Proteica
8.
Anticancer Agents Med Chem ; 22(9): 1735-1741, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34515012

RESUMO

BACKGROUND: Breast cancer is one of the most common cancers worldwide among women, and angiogenesis has an important effect on its growth and metastasis. Glipizide, which is a widely used drug for type 2 diabetes mellitus, has been reported to inhibit tumor growth and metastasis by upregulating the expression of natriuretic peptide receptor A (NPRA). Atrial natriuretic peptide (ANP), the receptor of NPRA, plays an important role in angiogenesis. The purpose of this study was to explore the effect of glipizide combined with ANP on breast cancer growth and metastasis. METHODS: This study aimed at investigating the effect of glipizide combined with ANP on breast cancer. Glipizide, ANP, or glipizide combined with ANP was intraperitoneally injected into MMTV-PyMT mice. To explore whether the anticancer efficacy of glipizide combined with ANP was correlated with angiogenesis, a tube formation assay was performed. RESULTS: Glipizide combined with ANP was found to inhibit breast cancer growth and metastasis in MMTV-PyMT mice, which spontaneously develop breast cancer. Furthermore, the inhibitory effect of ANP combined with glipizide was better than that of glipizide alone. ANP combined with glipizide significantly inhibited tube formation of human umbilical vein endothelial cells (HUVECs) by suppressing vascular endothelial growth factor (VEGF)/VEGFR2 (vascular endothelial growth factor receptor 2) signaling. CONCLUSION: These results demonstrate that glipizide combined with ANP has a greater potential than glipizide alone to be repurposed as an effective agent for the treatment of breast cancer by targeting tumor-induced angiogenesis.


Assuntos
Neoplasias da Mama , Diabetes Mellitus Tipo 2 , Inibidores da Angiogênese/farmacologia , Inibidores da Angiogênese/uso terapêutico , Animais , Fator Natriurético Atrial/farmacologia , Fator Natriurético Atrial/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Movimento Celular , Proliferação de Células , Diabetes Mellitus Tipo 2/tratamento farmacológico , Feminino , Glipizida/farmacologia , Glipizida/uso terapêutico , Células Endoteliais da Veia Umbilical Humana , Humanos , Camundongos , Neovascularização Patológica/tratamento farmacológico , Neovascularização Patológica/patologia , Fator A de Crescimento do Endotélio Vascular/metabolismo , Receptor 2 de Fatores de Crescimento do Endotélio Vascular
9.
Nature ; 589(7843): 542-547, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33238289

RESUMO

Positron emission tomography (PET) radioligands (radioactively labelled tracer compounds) are extremely useful for in vivo characterization of central nervous system drug candidates, neurodegenerative diseases and numerous oncology targets1. Both tritium and carbon-11 radioisotopologues are generally necessary for in vitro and in vivo characterization of radioligands2, yet there exist few radiolabelling protocols for the synthesis of either, inhibiting the development of PET radioligands. The synthesis of such radioligands also needs to be very rapid owing to the short half-life of carbon-11. Here we report a versatile and rapid metallaphotoredox-catalysed method for late-stage installation of both tritium and carbon-11 into the desired compounds via methylation of pharmaceutical precursors bearing aryl and alkyl bromides. Methyl groups are among the most prevalent structural elements found in bioactive molecules, and so this synthetic approach simplifies the discovery of radioligands. To demonstrate the breadth of applicability of this technique, we perform rapid synthesis of 20 tritiated and 10 carbon-11-labelled complex pharmaceuticals and PET radioligands, including a one-step radiosynthesis of the clinically used compounds [11C]UCB-J and [11C]PHNO. We further outline the direct utility of this protocol for preclinical PET imaging and its translation to automated radiosynthesis for routine radiotracer production in human clinical imaging. We also demonstrate this protocol for the installation of other diverse and pharmaceutically useful isotopes, including carbon-14, carbon-13 and deuterium.


Assuntos
Técnicas de Química Sintética , Ligantes , Processos Fotoquímicos , Tomografia por Emissão de Pósitrons/métodos , Radioisótopos/química , Alquilação , Radioisótopos de Carbono/química , Glipizida/análogos & derivados , Glipizida/química , Metilação , Oxirredução
10.
Value Health ; 23(4): 434-440, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32327160

RESUMO

OBJECTIVES: Outcomes-based contracts tie rebates and discounts for expensive drugs to outcomes. The objective was to estimate the utility of outcomes-based contracts for diabetes medications using real-world data and to identify methodologic limitations of this approach. METHODS: A population-based cohort study of adults newly prescribed a medication for diabetes with a publicly announced outcomes-based contract (ie, exenatide microspheres ["exenatide"], dulaglutide, or sitagliptin) was conducted. The comparison group included patients receiving canagliflozin or glipizide. The primary outcome was announced in the outcomes-based contract: the percentage of adults with a follow-up hemoglobin A1C <8% up to 1 year later. Secondary outcomes included the percentage of patients diagnosed with hypoglycemia and the cost of a 1-month supply. RESULTS: Thousands of adults newly filled prescriptions for exenatide (n = 5079), dulaglutide (n = 6966), sitagliptin (n = 40 752), canagliflozin (n = 16 404), or glipizide (n = 59 985). The percentage of adults subsequently achieving a hemoglobin A1C below 8% ranged from 83% (dulaglutide, sitagliptin) to 71% (canagliflozin). The rate of hypoglycemia was 25 per 1000 person-years for exenatide, 37 per 1000 person-years for dulaglutide, 28 per 1000 person-years for sitagliptin, 18 per 1000 person-years for canagliflozin, and 34 per 1000 person-years for glipizide. The cash price for a 1-month supply was $847 for exenatide, $859 for dulaglutide, $550 for sitagliptin, $608 for canagliflozin, and $14 for glipizide. CONCLUSION: Outcomes-based pricing of diabetes medications has the potential to lower the cost of medications, but using outcomes such as hemoglobin A1C may not be clinically meaningful because similar changes in A1C can be achieved with generic medications at a far lower cost.


Assuntos
Contratos/economia , Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/administração & dosagem , Avaliação de Resultados em Cuidados de Saúde/métodos , Idoso , Canagliflozina/administração & dosagem , Canagliflozina/economia , Estudos de Coortes , Diabetes Mellitus Tipo 2/economia , Exenatida/administração & dosagem , Exenatida/economia , Feminino , Seguimentos , Glipizida/administração & dosagem , Glipizida/economia , Peptídeos Semelhantes ao Glucagon/administração & dosagem , Peptídeos Semelhantes ao Glucagon/análogos & derivados , Peptídeos Semelhantes ao Glucagon/economia , Humanos , Hipoglicemiantes/economia , Fragmentos Fc das Imunoglobulinas/administração & dosagem , Fragmentos Fc das Imunoglobulinas/economia , Masculino , Pessoa de Meia-Idade , Proteínas Recombinantes de Fusão/administração & dosagem , Proteínas Recombinantes de Fusão/economia , Fosfato de Sitagliptina/administração & dosagem , Fosfato de Sitagliptina/economia
11.
Shock ; 51(2): 247-255, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-29401137

RESUMO

BACKGROUND: Potassium-(K)-channel inhibitors may increase systemic vascular resistance in vasodilatory shock states. OBJECTIVE: The purpose of the present study was to compare the macro- and microvascular effects of the adenosine triphosphate-sensitive K-channel-(KATP)-inhibitor glipizide and the nonselective K-channel inhibitor tetraethylammonium (TEA) in ovine endotoxemic shock and septic shock in rats. DESIGN: Two randomized, controlled laboratory studies. ANIMALS: Thirty female sheep and 40 male Sprague Dawley rats. SETTING: Animal research facility INTERVENTION:: Systemic hemodynamics were analyzed in ovine endotoxemic shock with guideline-oriented supportive therapy. Sheep were allocated to three treatment groups for 12 h: glipizide 10 mg kg·h, TEA 8 mg kg·h, or 0.9% saline. The microvascular effects of each drug were evaluated in septic rats (cecal ligation and puncture model) receiving a 2-h infusion of each study drug: glipizide 20 mg kg·h; TEA 50 mg kg·h, or 0.9% saline, respectively, followed by intravital microscopy of villi microcirculation. RESULTS: Compared with the control group, glipizide infusion increased systemic vascular resistance index and decreased cardiac index and heart rate (HR) in sheep (P < 0.05), whereas TEA infusion decreased HR and resulted in a decreased survival time (P = 0.001). In rats, glipizide infusion resulted in an increase in mean arterial pressure and a decrease in HR compared with baseline measurement (P < 0.05) without relevant effects on the villi microcirculation. TEA decreased HR and decreased capillary perfusion of the villi microcirculation compared with the sham group (P = 0.002). CONCLUSIONS: Selective inhibition of KATP-channels in ovine endotoxemic shock with glipizide partially restored vasomotor tone without exerting harmful effects on intestinal microcirculation in septic shock in rats. On the contrary, nonselective K-channel inhibition with TEA showed deleterious effects in both models, including impaired microcirculation and decreased survival time. Future research on glipizide in vasodilatory shock may be warranted.


Assuntos
Endotoxemia , Glipizida/farmacologia , Microcirculação/efeitos dos fármacos , Bloqueadores dos Canais de Potássio/farmacologia , Choque Séptico , Resistência Vascular/efeitos dos fármacos , Animais , Endotoxemia/sangue , Endotoxemia/induzido quimicamente , Endotoxemia/tratamento farmacológico , Endotoxemia/fisiopatologia , Feminino , Masculino , Ratos , Ratos Sprague-Dawley , Ovinos , Choque Séptico/sangue , Choque Séptico/induzido quimicamente , Choque Séptico/tratamento farmacológico , Choque Séptico/fisiopatologia
12.
Transl Res ; 205: 51-63, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30452888

RESUMO

In diabetes, stromal cell-derived factor-1 (SDF-1) expression and progenitor cell recruitment are reduced. Dipeptidyl peptidase-4 (DPP-4) inhibits SDF-1 expression and progenitor cell recruitment. Here we examined the impact of the DPP-4 inhibitor, MK0626, on progenitor cell kinetics in the context of wound healing. Wildtype (WT) murine fibroblasts cultured under high-glucose to reproduce a diabetic microenvironment were exposed to MK0626, glipizide, or no treatment, and SDF-1 expression was measured with ELISA. Diabetic mice received MK0626, glipizide, or no treatment for 6 weeks and then were wounded. Immunohistochemistry was used to quantify neovascularization and SDF-1 expression. Gene expression was measured at the RNA and protein level using quantitative polymerase chain reaction and ELISA, respectively. Flow cytometry was used to characterize bone marrow-derived mesenchymal progenitor cell (BM-MPC) population recruitment to wounds. BM-MPC gene expression was assayed using microfluidic single cell analysis. WT murine fibroblasts exposed to MK0626 demonstrated increased SDF-1 expression. MK0626 treatment significantly accelerated wound healing and increased wound vascularity, SDF-1 expression, and dermal thickness in diabetic wounds. MK0626 treatment increased the number of BM-MPCs present in bone marrow and in diabetic wounds. MK0626 had no effect on BM-MPC population dynamics. BM-MPCs harvested from MK0626-treated mice exhibited increased chemotaxis in response to SDF-1 when compared to diabetic controls. Treatment with a DPP-4 inhibitor significantly improved wound healing, angiogenesis, and endogenous progenitor cell recruitment in the setting of diabetes.


Assuntos
Diabetes Mellitus Experimental/complicações , Dipeptidil Peptidase 4/efeitos dos fármacos , Inibidores da Dipeptidil Peptidase IV/farmacologia , Células-Tronco Hematopoéticas/efeitos dos fármacos , Neovascularização Patológica , Cicatrização/efeitos dos fármacos , Ferimentos e Lesões/fisiopatologia , Animais , Quimiocina CXCL12/metabolismo , Glipizida/farmacologia , Células-Tronco Hematopoéticas/citologia , Camundongos , Camundongos Endogâmicos C57BL , Triazóis/farmacologia
13.
Drug Metab Lett ; 13(1): 19-24, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30398126

RESUMO

BACKGROUND: Polypharmacy, that is, two (or more) drugs administered together, may cause chemical or pharmacological interactions. Such interactions may alter the effect of either agent, leading to decrease or increase effectiveness of the drugs, which may cause adverse effects. The co-intake of complementary and alternative medicines with therapeutic medicine are supposed to influence pharmacodynamics or pharmacokinetics of the latter. OBJECTIVE: This study was conducted to determine the interaction of glipizide (GZ) with an aqueous extract of Azadirachta indica (AZI) leaves. METHOD: The pharmacokinetics and pharmacodynamics of glipizide was evaluated in High Fat diet (HFD) and streptozotocin induced diabetic Sprague-Dawley rats. Two doses of the AZI leaf extract (250 and 500 mg/kg) were administered alone or in combination with GZ (5 mg/kg) and serum glucose during oral glucose tolerance test, AST, ALT, and ALP levels were as estimated. In vitro CYP3A activity of AZI at 50 µg and 100 µg was assessed using liver microsomes. RESULTS: In the glucose tolerance test, AZI and GZ showed a hypoglycemic effect. However, the hypoglycemic effect was lower when AZI was administered in combination with GZ compared with GZ alone. AZI at 100 µg has shown significant potentiation of CYP3A activity. AZI (500 mg/kg) pretreatment significantly decreased AUC and increased Tmax to 8 h. CONCLUSION: This indicated that the pharmacokinetics and pharmacodynamics of GZ altered by AZI might be due to the induction of CYP3A activity. In conclusion, AZI can decrease the bioavailability of GZ, and hence, it should be cautiously used.


Assuntos
Azadirachta/química , Diabetes Mellitus Tipo 2/tratamento farmacológico , Glipizida/farmacologia , Hipoglicemiantes/farmacologia , Extratos Vegetais/farmacologia , Animais , Área Sob a Curva , Glicemia/análise , Glicemia/efeitos dos fármacos , Citocromo P-450 CYP3A/metabolismo , Diabetes Mellitus Experimental , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/etiologia , Dieta Hiperlipídica/efeitos adversos , Interações Ervas-Drogas , Humanos , Masculino , Folhas de Planta/química , Polimedicação , Ratos , Ratos Sprague-Dawley , Estreptozocina/toxicidade
14.
Cochrane Database Syst Rev ; 9: CD011798, 2018 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-30246878

RESUMO

BACKGROUND: Diabetes is the commonest cause of chronic kidney disease (CKD). Both conditions commonly co-exist. Glucometabolic changes and concurrent dialysis in diabetes and CKD make glucose-lowering challenging, increasing the risk of hypoglycaemia. Glucose-lowering agents have been mainly studied in people with near-normal kidney function. It is important to characterise existing knowledge of glucose-lowering agents in CKD to guide treatment. OBJECTIVES: To examine the efficacy and safety of insulin and other pharmacological interventions for lowering glucose levels in people with diabetes and CKD. SEARCH METHODS: We searched the Cochrane Kidney and Transplant Register of Studies up to 12 February 2018 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov. SELECTION CRITERIA: All randomised controlled trials (RCTs) and quasi-RCTs looking at head-to-head comparisons of active regimens of glucose-lowering therapy or active regimen compared with placebo/standard care in people with diabetes and CKD (estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m2) were eligible. DATA COLLECTION AND ANALYSIS: Four authors independently assessed study eligibility, risk of bias, and quality of data and performed data extraction. Continuous outcomes were expressed as post-treatment mean differences (MD). Adverse events were expressed as post-treatment absolute risk differences (RD). Dichotomous clinical outcomes were presented as risk ratios (RR) with 95% confidence intervals (CI). MAIN RESULTS: Forty-four studies (128 records, 13,036 participants) were included. Nine studies compared sodium glucose co-transporter-2 (SGLT2) inhibitors to placebo; 13 studies compared dipeptidyl peptidase-4 (DPP-4) inhibitors to placebo; 2 studies compared glucagon-like peptide-1 (GLP-1) agonists to placebo; 8 studies compared glitazones to no glitazone treatment; 1 study compared glinide to no glinide treatment; and 4 studies compared different types, doses or modes of administration of insulin. In addition, 2 studies compared sitagliptin to glipizide; and 1 study compared each of sitagliptin to insulin, glitazars to pioglitazone, vildagliptin to sitagliptin, linagliptin to voglibose, and albiglutide to sitagliptin. Most studies had a high risk of bias due to funding and attrition bias, and an unclear risk of detection bias.Compared to placebo, SGLT2 inhibitors probably reduce HbA1c (7 studies, 1092 participants: MD -0.29%, -0.38 to -0.19 (-3.2 mmol/mol, -4.2 to -2.2); I2 = 0%), fasting blood glucose (FBG) (5 studies, 855 participants: MD -0.48 mmol/L, -0.78 to -0.19; I2 = 0%), systolic blood pressure (BP) (7 studies, 1198 participants: MD -4.68 mmHg, -6.69 to -2.68; I2 = 40%), diastolic BP (6 studies, 1142 participants: MD -1.72 mmHg, -2.77 to -0.66; I2 = 0%), heart failure (3 studies, 2519 participants: RR 0.59, 0.41 to 0.87; I2 = 0%), and hyperkalaemia (4 studies, 2788 participants: RR 0.58, 0.42 to 0.81; I2 = 0%); but probably increase genital infections (7 studies, 3086 participants: RR 2.50, 1.52 to 4.11; I2 = 0%), and creatinine (4 studies, 848 participants: MD 3.82 µmol/L, 1.45 to 6.19; I2 = 16%) (all effects of moderate certainty evidence). SGLT2 inhibitors may reduce weight (5 studies, 1029 participants: MD -1.41 kg, -1.8 to -1.02; I2 = 28%) and albuminuria (MD -8.14 mg/mmol creatinine, -14.51 to -1.77; I2 = 11%; low certainty evidence). SGLT2 inhibitors may have little or no effect on the risk of cardiovascular death, hypoglycaemia, acute kidney injury (AKI), and urinary tract infection (low certainty evidence). It is uncertain whether SGLT2 inhibitors have any effect on death, end-stage kidney disease (ESKD), hypovolaemia, fractures, diabetic ketoacidosis, or discontinuation due to adverse effects (very low certainty evidence).Compared to placebo, DPP-4 inhibitors may reduce HbA1c (7 studies, 867 participants: MD -0.62%, -0.85 to -0.39 (-6.8 mmol/mol, -9.3 to -4.3); I2 = 59%) but may have little or no effect on FBG (low certainty evidence). DPP-4 inhibitors probably have little or no effect on cardiovascular death (2 studies, 5897 participants: RR 0.93, 0.77 to 1.11; I2 = 0%) and weight (2 studies, 210 participants: MD 0.16 kg, -0.58 to 0.90; I2 = 29%; moderate certainty evidence). Compared to placebo, DPP-4 inhibitors may have little or no effect on heart failure, upper respiratory tract infections, and liver impairment (low certainty evidence). Compared to placebo, it is uncertain whether DPP-4 inhibitors have any effect on eGFR, hypoglycaemia, pancreatitis, pancreatic cancer, or discontinuation due to adverse effects (very low certainty evidence).Compared to placebo, GLP-1 agonists probably reduce HbA1c (7 studies, 867 participants: MD -0.53%, -1.01 to -0.06 (-5.8 mmol/mol, -11.0 to -0.7); I2 = 41%; moderate certainty evidence) and may reduce weight (low certainty evidence). GLP-1 agonists may have little or no effect on eGFR, hypoglycaemia, or discontinuation due to adverse effects (low certainty evidence). It is uncertain whether GLP-1 agonists reduce FBG, increase gastrointestinal symptoms, or affect the risk of pancreatitis (very low certainty evidence).Compared to placebo, it is uncertain whether glitazones have any effect on HbA1c, FBG, death, weight, and risk of hypoglycaemia (very low certainty evidence).Compared to glipizide, sitagliptin probably reduces hypoglycaemia (2 studies, 551 participants: RR 0.40, 0.23 to 0.69; I2 = 0%; moderate certainty evidence). Compared to glipizide, sitagliptin may have had little or no effect on HbA1c, FBG, weight, and eGFR (low certainty evidence). Compared to glipizide, it is uncertain if sitagliptin has any effect on death or discontinuation due to adverse effects (very low certainty).For types, dosages or modes of administration of insulin and other head-to-head comparisons only individual studies were available so no conclusions could be made. AUTHORS' CONCLUSIONS: Evidence concerning the efficacy and safety of glucose-lowering agents in diabetes and CKD is limited. SGLT2 inhibitors and GLP-1 agonists are probably efficacious for glucose-lowering and DPP-4 inhibitors may be efficacious for glucose-lowering. Additionally, SGLT2 inhibitors probably reduce BP, heart failure, and hyperkalaemia but increase genital infections, and slightly increase creatinine. The safety profile for GLP-1 agonists is uncertain. No further conclusions could be made for the other classes of glucose-lowering agents including insulin. More high quality studies are required to help guide therapeutic choice for glucose-lowering in diabetes and CKD.


Assuntos
Diabetes Mellitus/tratamento farmacológico , Nefropatias Diabéticas/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Insulina/uso terapêutico , Insuficiência Renal Crônica/tratamento farmacológico , Causas de Morte , Diabetes Mellitus/sangue , Diabetes Mellitus/mortalidade , Nefropatias Diabéticas/sangue , Nefropatias Diabéticas/mortalidade , Inibidores da Dipeptidil Peptidase IV/uso terapêutico , Glipizida/efeitos adversos , Glipizida/uso terapêutico , Peptídeo 1 Semelhante ao Glucagon/agonistas , Hemoglobinas Glicadas/efeitos dos fármacos , Humanos , Hipoglicemiantes/efeitos adversos , Insulina/efeitos adversos , Ensaios Clínicos Controlados Aleatórios como Assunto , Insuficiência Renal Crônica/sangue , Insuficiência Renal Crônica/mortalidade , Fosfato de Sitagliptina/efeitos adversos , Fosfato de Sitagliptina/uso terapêutico , Transportador 2 de Glucose-Sódio , Inibidores do Transportador 2 de Sódio-Glicose , Tiazolidinedionas/uso terapêutico
15.
Photochem Photobiol ; 94(6): 1151-1158, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30066952

RESUMO

Reactive oxygen species (ROS) have been described in their double physiological function, helping in the maintenance of health as well as contributing to oxidative stress. Diabetes mellitus is a chronical disease nearly related to oxidative stress, whose treatment (in type II variant) consists in the administration of antidiabetic compounds (Andb) such as Gliclazide (Gli) and Glipizide (Glip). In this context, as Andb may be exposed to high ROS concentrations in diabetic patients, we have studied the potential ROS-mediated degradation of Gli and Glip through photosensitized processes, in the presence of Riboflavin (Rf) vitamin. We found that singlet oxygen (O2 (1 ∆g )) participated in the Rf-sensitized photodegradation of both Andb, and also superoxide radical anion in the case of Gli. Two principal products derived from O2 (1 ∆g )-mediated degradation of Gli were identified and their chemical structures characterized, through HPLC mass spectrometry. O2 (1 ∆g )-mediated degradation products and their toxicity was assayed on Vero cell line. These studies demonstrated that neither Gli nor its photoproducts caused cytotoxic effect under the experimental conditions assayed. Our results show strong evidences of ROS-mediated Andb degradation, which may involve the reduction or loss of their therapeutic action, as well as potential cytotoxicity derived from their oxidation products.


Assuntos
Gliclazida/química , Glipizida/química , Hipoglicemiantes/química , Fármacos Fotossensibilizantes/química , Riboflavina/química , Oxigênio Singlete/química , Superóxidos/química , Animais , Biotransformação/efeitos da radiação , Sobrevivência Celular/efeitos dos fármacos , Chlorocebus aethiops , Diabetes Mellitus Tipo 2/tratamento farmacológico , Gliclazida/metabolismo , Gliclazida/farmacologia , Glipizida/metabolismo , Glipizida/farmacologia , Humanos , Hipoglicemiantes/metabolismo , Hipoglicemiantes/farmacologia , Cinética , Luz , Oxirredução , Fotólise , Fármacos Fotossensibilizantes/metabolismo , Riboflavina/metabolismo , Oxigênio Singlete/metabolismo , Soluções , Espectrometria de Fluorescência , Superóxidos/metabolismo , Células Vero
16.
Rev. costarric. cardiol ; 19(1/2): 13-17, ene.-dic. 2017. tab
Artigo em Espanhol | LILACS | ID: biblio-900881

RESUMO

Resumen La Diabetes Mellitus tipo 2 (DM-2) es un equivalente de riesgo cardiovascular. Existe una gran variedad de fármacos para el control de la glicemia en los pacientes con DM-2, los cuales tienen diferencias en su perfil cardiovascular, unos han demostrado un beneficio en la reducción de riesgo de eventos cardiovasculares, otros tienen un efecto neutro, y en el caso de otros fármacos como las sulfonilureas y las tiazolinedionas existe dudas sobre su seguridad cardiovascular. Sien do DM-2 un equivalente de riesgo coronario, es fundamental tomar en cuenta el perfil de riesgo cardiovascular de estos medicamentos a la hora de iniciar alguna de estas drogas y no solo su eficacia para controlar los niveles de glicemia. El objetivo de esta revisión es comentar sobre los estudios más recientes que evalúan el riesgo cardiovascular con el uso de los distintos antidiabéticos orales.


Abstract Cardiovascular Safety of Oral Antidiabetics Diabetes Mellitus type 2 (DM-2) is an equivalent of cardiovascular risk. There is a wide variety of drugs for the glycemic control in patients with DM-2, which have differences in their cardiovascular profile, some have shown a benefit in reducing the risk of cardiovascular events, others have a neutral effect, and in the case of other drugs such as sulfonylurea and thiazolidinedione, there are doubts about their cardiovascular safety. Being DM-2 an equivalent of coronary risk, it is essential to consider the cardiovascular risk profile of these medicines when starting any of these drugs and not only their effectiveness in controlling glycaemia levels. The objective of this review is to comment on the most recent studies evaluating cardiovascular risk with the use of different oral antidiabetics.


Assuntos
Humanos , Glicemia , Glibureto/uso terapêutico , Tiazolidinedionas/uso terapêutico , Complicações do Diabetes , Diabetes Mellitus Tipo 2/tratamento farmacológico , Rosiglitazona/uso terapêutico , Pioglitazona/uso terapêutico , Glipizida/uso terapêutico , Hipoglicemiantes , Metformina/uso terapêutico
17.
J Control Release ; 256: 193-202, 2017 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-28412224

RESUMO

We developed a step-by-step experimental protocol using differential scanning calorimetry (DSC), dynamic vapour sorption (DVS), polarized light microscopy (PLM) and a small-scale dissolution apparatus (µDISS Profiler) to investigate the mechanism (solid-to-solid or solution-mediated) by which crystallization of amorphous drugs occurs upon dissolution. This protocol then guided how to stabilize the amorphous formulation. Indapamide, metolazone, glibenclamide and glipizide were selected as model drugs and HPMC (Pharmacoat 606) and PVP (K30) as stabilizing polymers. Spray-dried amorphous indapamide, metolazone and glibenclamide crystallized via solution-mediated nucleation while glipizide suffered from solid-to-solid crystallization. The addition of 0.001%-0.01% (w/v) HPMC into the dissolution medium successfully prevented the crystallization of supersaturated solutions of indapamide and metolazone whereas it only reduced the crystallization rate for glibenclamide. Amorphous solid dispersion (ASD) formulation of glipizide and PVP K30, at a ratio of 50:50% (w/w) reduced but did not completely eliminate the solid-to-solid crystallization of glipizide even though the overall dissolution rate was enhanced both in the absence and presence of HPMC. Raman spectroscopy indicated the formation of a glipizide polymorph in the dissolution medium with higher solubility than the stable polymorph. As a complementary technique, molecular dynamics (MD) simulations of indapamide and glibenclamide with HPMC was performed. It was revealed that hydrogen bonding patterns of the two drugs with HPMC differed significantly, suggesting that hydrogen bonding may play a role in the greater stabilizing effect on supersaturation of indapamide, compared to glibenclamide.


Assuntos
Glipizida/química , Glibureto/química , Indapamida/química , Metolazona/química , Varredura Diferencial de Calorimetria , Cristalização , Composição de Medicamentos , Liberação Controlada de Fármacos , Estabilidade de Medicamentos , Ligação de Hidrogênio , Derivados da Hipromelose/química , Simulação de Dinâmica Molecular , Povidona/química , Análise Espectral Raman
18.
Eur Rev Med Pharmacol Sci ; 21(4): 867-872, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-28272693

RESUMO

OBJECTIVE: Diabetes affects the renal function at a certain stage. Oral medication glipizide plays a hypoglycemic effect mainly through releasing insulin, while more insulin is derived from islet ß cells. It is still controversy whether antidiabetics. This study mainly intends to investigate the role of glipizide in inhibiting renal interstitial fibrosis. MATERIALS AND METHODS: A total of 93 SD rats were purchased from Guangdong animal monitoring and established unilateral ureteral obstruction (UUO) model to simulate renal interstitial fibrosis. Forty rats in the experimental group received glipizide intraperitoneal injection for a week at 30 days after modeling, while another 40 rats in the control group received a normal saline injection. The last 10 rats were treated as blank group. Hematoxylin and eosin (HE) staining was applied to test renal interstitial fibrosis. Immunohistochemistry was used to detect fibronectin expression in glomerular and renal tubules. AKT signaling pathway related factors expression was measured by Western blot to determine AKT signal activation. RESULTS: HE staining showed that the entire kidney cytoplasm red dye becomes shallow, renal medulla gradually disappears, renal tubular epithelial cells enlarge, vacuoles degeneration, renal tubule and collecting tube expansion, inflammatory cells infiltration after UUO modeling. Glipizide treatment decreased dilated renal tubule number, improved glomerulus integrity, and reduced inflammatory infiltration. Fibronectin level in the experimental group was significantly lower than that in control (p<0.05). Western blot revealed that p-AKT expression downregulated after glipizide treatment. CONCLUSIONS: Glipizide blocks renal interstitial fibrosis by inhibiting AKT signaling pathway.


Assuntos
Glipizida/farmacologia , Nefropatias/tratamento farmacológico , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , Animais , Fibrose , Rim/patologia , Ratos , Ratos Sprague-Dawley , Obstrução Ureteral
19.
Metabolism ; 67: 1-13, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28081772

RESUMO

OBJECTIVE: The metabolic amplification of insulin secretion is the sequence of events which enables the secretory response to a fuel secretagogue to exceed the secretory response to a purely depolarizing stimulus. The signals in this pathway are incompletely understood. Here, we have characterized an experimental procedure by which the amplifying response to glucose is reversibly desensitized, while the response to α-ketoisocaproic acid (KIC) is unchanged. MATERIALS/METHODS: Insulin secretion, NAD(P)H- and FAD-autofluorescence, Fura-2 fluorescence and oxygen consumption were measured in perifused NMRI mouse islets. The ATP- and ADP-contents were measured in statically incubated mouse islets. All islets were freshly isolated. RESULTS: While the original observation on the dissociation between glucose- and KIC-amplification was obtained with islets that had been exposed to a high concentration of the sulfonylurea glipizide in the absence of glucose, we now show that in the absence of exogenous fuel a moderate depolarization, irrespective of its mechanism, progressively decreased the amplification in response to both glucose and KIC. However, the amplification in response to glucose declined faster, so a time window exists where glucose was already inefficient, whereas KIC was of unimpaired efficiency. Measurements of adenine nucleotides, NAD(P)H- and FAD-autofluorescence, and oxygen consumption point to a central role of the mitochondrial metabolism in this process. The desensitization could be quickly reversed by increasing oxidative deamination of glutamate and consequently anaplerosis of the citrate cycle. CONCLUSION: Depolarization in the absence of exogenous fuel may be a useful model to identify those signals which are indispensable for the generation of metabolic amplification.


Assuntos
Glucose/farmacologia , Insulina/metabolismo , Cetoácidos/farmacologia , Transdução de Sinais/efeitos dos fármacos , Nucleotídeos de Adenina/metabolismo , Animais , Flavina-Adenina Dinucleotídeo/metabolismo , Glipizida/farmacologia , Hipoglicemiantes/farmacologia , Secreção de Insulina , Células Secretoras de Insulina , Ilhotas Pancreáticas/efeitos dos fármacos , Ilhotas Pancreáticas/metabolismo , Camundongos , Camundongos Knockout , NADP/metabolismo , Consumo de Oxigênio , Receptores de Sulfonilureias/genética
20.
Metabolism ; 65(9): 1225-9, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27506729

RESUMO

OBJECTIVE: Stimulation of the ß-cell metabolism by glucose and other fuels triggers insulin release by enhancing the mitochondrial ATP production and acutely amplifies the secretory response by increase in mitochondrial export of metabolites. We aimed to narrow down the uniform final reaction steps mediating fuel-induced acute amplification of insulin secretion. MATERIAL/METHODS: Insulin secretion and metabolic parameters were measured in isolated mouse islets exposed to the sulfonylurea glipizide in high concentration (closing all ATP-sensitive K(+) channels) during the entire experiment. Fuel-induced effects were examined after treating the islets for one hour with medium devoid of fuels. This experimental design prevented acute amplification, but only when glucose was the sole fuel. RESULTS: Strong amplification of insulin secretion by α-ketoisocaproate or glucose combined with α-ketoisovalerate (supplying mitochondrial oxaloacetate) was abolished within 14min after transition to medium devoid of fuels. After transition from medium containing glucose plus α-ketoisovalerate to medium containing solely glucose or α-ketoisovalerate, amplification (strong or weak, respectively) occurred until the end of the experiment. Glucose (alone or combined with α-ketoisovalerate) increased the total acetyl-CoA content as intensely as α-ketoisocaproate. Low concentrations of α-ketoisovalerate or α-ketoisocaproate were sufficient for saturation of acetyl-CoA increase, but caused no or only weak amplification, respectively. No acetyl-CoA increases occurred in the absence of glipizide. CONCLUSIONS: Glucose and other fuels regulate acute amplification of insulin secretion by controlling the supply of acetyl-CoA to the ß-cell cytosol. Cytosolic acetyl-CoA does not amplify by serving as substrate for syntheses of metabolic intermediates, but amplifies by acting as substrate for cytosolic protein acetylation.


Assuntos
Acetilcoenzima A/metabolismo , Citosol/metabolismo , Células Secretoras de Insulina/metabolismo , Insulina/metabolismo , Ilhotas Pancreáticas/efeitos dos fármacos , Ilhotas Pancreáticas/metabolismo , Difosfato de Adenosina/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Meios de Cultura , Glipizida/farmacologia , Glucose/farmacologia , Técnicas In Vitro , Secreção de Insulina , Canais KATP/efeitos dos fármacos , Cetoácidos/farmacologia , Camundongos , Bloqueadores dos Canais de Potássio/farmacologia
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