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1.
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
2.
Mol Biol Rep ; 47(9): 6561-6572, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32789574

RESUMO

After confirmation of the presence of adiponectin (ADPN) receptors and intra-cellular binding proteins in coronary artery smooth muscle cells (VSMC), we tested the hypotheses that, in acute insulin resistance: (i) the activation/inactivation of metabolic and mitogenic insulin signaling pathways are inversely affected by ADPN and, (ii) changes in VSMC migration/proliferation rates correlate with signal activity/inactivity. In primary cultures of VSMC exposed to high glucose and palmitate plus insulin, the expression of PI-3 kinase (Akt and m-TOR), MAP-Kinase (Erk and p-38) molecules, and inflammatory markers (TLR-4 and IkB-α) were assessed with Western blot, in the absence/presence of AdipoRon (AR). Migration and proliferation rates were measured in similar experimental conditions. There were decreases of ~ 25% (p-Akt) and 40-60% (p-mTOR) expressions with high glucose/palmitate, which reversed when AR was added were. Elevations in p-Erk and p-p38 expressions were obliterated by AR. Although, no changes were detected with high glucose and palmitate, when AR was added, a decline in inflammatory activity was substantiated by a ~ 50% decrease in TLR-4 and 40-60% increase in IkBα expression. Functional assays showed 10-20% rise in VSMC proliferation with high glucose and palmitate, but addition of AR lead to 15-25% decline. The degree of VSMC migration was reduced with AR addition by ~ 15%, ~ 35% and 55%, in VSMC exposed to 5 mM, 25 mM glucose and 25 mM + 200 µM palmitate, respectively. Changes in intracellular molecular messaging in experiments mimicking acute insulin resistance suggest that anti-inflammatory and anti-atherogenic actions of ADPN in VSMC are mediated via insulin signaling pathways.


Assuntos
Adiponectina/metabolismo , Insulina/isolamento & purificação , Insulina/farmacologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Músculo Liso Vascular/metabolismo , Piperidinas/farmacologia , Linhagem Celular , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Glucose/farmacologia , Humanos , Proteínas I-kappa B/metabolismo , Inflamação/metabolismo , Insulina/metabolismo , Palmitatos/farmacologia , Fosforilação , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptores de Adiponectina/agonistas , Serina-Treonina Quinases TOR/metabolismo , Receptor 4 Toll-Like/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno
3.
Endocrinol Diabetes Metab ; 1(2): e00014, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30815550

RESUMO

BACKGROUND: Left ventricular (LV) diastolic dysfunction commonly is observed in individuals with type 2 diabetes mellitus (T2DM). We employed transthoracic echocardiography (TTE) and cardiac magnetic resonance imaging (CMRI) to investigate the hypothesis that LV diastolic dysfunction in T2DM is associated with poor glycemic control. METHODS: Forty subjects, 21 with normal glucose tolerance (NGT) and 19 with T2DM, were studied with CMRI and TTE to assess LV function. Early-to-late transmitral flow ratio (E/A) and deceleration time (DecT) were assessed with both modalities. Normalized (to body surface area) end-diastolic volume (EDV/BSA) and normalized peak LV filling rate (pLVFR/BSA) were assessed with CMRI. Early transmitral flow velocity to septal velocity (E/e') and isovolumetric relaxation time (IVRT) were measured using TTE. Dimensional parameters were normalized to body surface area (BSA). RESULTS: CMRI measurements demonstrated impaired E/A (1.13 ± 0.34 vs 1.62 ± 0.42, P < .001), increased DecT (174 ± 46 ms vs 146 ± 15, P = .005), as well as lower EDV/BSA (63 ± 10 vs 72 ± 9 mL/m2, P < .01) and pLVFR/BSA (189 ± 46 vs 221 ± 48 mL s-1 m-2, P < .05) in T2DM subjects. TTE measurements revealed lower E/A (1.1 ± 0.4 vs 1.4 ± 0.2, P < .001) and E/e' (6.8 ± 1.5 vs 8.7 ± 2.0, P < .0001) with higher DecT (203 ± 22 ms vs 179 ± 18, P < .001) and IVRT (106 ± 14 ms vs 92 ± 10, P < .001) in T2DM. Multiple parameters of LV function: E/ACMRI (r = -.50, P = .001), E/ATTE (r = -.46, P < .005), pLVFR/BSA (r = -.35, P < .05), E/e' (r = -.46, P < .005), EDV/BSACMRI (r = -.51, P < .0001), EDV/BSATTE (r = -.42, P < .01) were negatively correlated with HbA1c. All but E/e' also were inversely correlated with fasting plasma glucose (FPG). CONCLUSIONS: Impaired LV diastolic function (DF) was found in T2DM subjects with both CMRI and TTE, and multiple LVDF parameters correlated negatively with HbA1c and FPG. These results indicate that impaired LVDF is inversely linked to glycemic control in T2DM patients.

4.
Hepatology ; 64(6): 2028-2037, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27639082

RESUMO

Glucagon-like peptide 1 (GLP-1) receptor agonists (GLP-1-RAs) act on multiple tissues, in addition to the pancreas. Recent studies suggest that GLP-1-RAs act on liver and adipose tissue to reduce insulin resistance (IR). Thus, we evaluated the acute effects of exenatide (EX) on hepatic (Hep-IR) and adipose (Adipo-IR) insulin resistance and glucose uptake. Fifteen male subjects (age = 56 ± 8 years; body mass index = 29 ± 1 kg/m2 ; A1c = 5.7 ± 0.1%) were studied on two occasions, with a double-blind subcutaneous injection of EX (5 µg) or placebo (PLC) 30 minutes before a 75-g oral glucose tolerance test (OGTT). During OGTT, we measured hepatic (HGU) and adipose tissue (ATGU) glucose uptake with [18 F]2-fluoro-2-deoxy-D-glucose/positron emission tomography, lipolysis (RaGly) with [U-2 H5 ]-glycerol, oral glucose absorption (RaO) with [U-13 C6 ]-glucose, and hepatic glucose production (EGP) with [6,6-2 H2 ]-glucose. Adipo-IR and Hep-IR were calculated as (FFA0-120min ) × (Ins0-120min ) and (EGP0-120min ) × (Ins0-120min ), respectively. EX reduced RaO, resulting in reduced plasma glucose and insulin concentration from 0 to 120 minutes postglucose ingestion. EX decreased Hep-IR (197 ± 28 to 130 ± 37; P = 0.02) and increased HGU of orally administered glucose (23 ± 4 to 232 ± 89 [µmol/min/L]/[µmol/min/kg]; P = 0.003) despite lower insulin (23 ± 5 vs. 41 ± 5 mU/L; P < 0.02). EX enhanced insulin suppression of RaGly by decreasing Adipo-IR (23 ± 4 to 13 ± 3; P = 0.009). No significant effect of insulin was observed on ATGU (EX = 1.16 ± 0.15 vs. PLC = 1.36 ± 0.13 [µmol/min/L]/[µmol/min/kg]). CONCLUSION: Acute EX administration (1) improves Hep-IR, decreases EGP, and enhances HGU and (2) reduces Adipo-IR, improves the antilipolytic effect of insulin, and reduces plasma free fatty acid levels during OGTT. (Hepatology 2016;64:2028-2037).


Assuntos
Tecido Adiposo/efeitos dos fármacos , Tecido Adiposo/diagnóstico por imagem , Hipoglicemiantes/uso terapêutico , Resistência à Insulina , Fígado/efeitos dos fármacos , Fígado/diagnóstico por imagem , Peptídeos/uso terapêutico , Tomografia por Emissão de Pósitrons , Peçonhas/uso terapêutico , Tecido Adiposo/metabolismo , Método Duplo-Cego , Exenatida , Glucose/metabolismo , Humanos , Fígado/metabolismo , Masculino , Pessoa de Meia-Idade
5.
Diabetes ; 64(10): 3406-12, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26116695

RESUMO

Glucagon-like peptide 1 receptors (GLP-1Rs) have been found in the brain, but whether GLP-1R agonists (GLP-1RAs) influence brain glucose metabolism is currently unknown. The study aim was to evaluate the effects of a single injection of the GLP-1RA exenatide on cerebral and peripheral glucose metabolism in response to a glucose load. In 15 male subjects with HbA1c of 5.7 ± 0.1%, fasting glucose of 114 ± 3 mg/dL, and 2-h glucose of 177 ± 11 mg/dL, exenatide (5 µg) or placebo was injected in double-blind, randomized fashion subcutaneously 30 min before an oral glucose tolerance test (OGTT). The cerebral glucose metabolic rate (CMRglu) was measured by positron emission tomography after an injection of [(18)F]2-fluoro-2-deoxy-d-glucose before the OGTT, and the rate of glucose absorption (RaO) and disposal was assessed using stable isotope tracers. Exenatide reduced RaO0-60 min (4.6 ± 1.4 vs. 13.1 ± 1.7 µmol/min ⋅ kg) and decreased the rise in mean glucose0-60 min (107 ± 6 vs. 138 ± 8 mg/dL) and insulin0-60 min (17.3 ± 3.1 vs. 24.7 ± 3.8 mU/L). Exenatide increased CMRglu in areas of the brain related to glucose homeostasis, appetite, and food reward, despite lower plasma insulin concentrations, but reduced glucose uptake in the hypothalamus. Decreased RaO0-60 min after exenatide was inversely correlated to CMRglu. In conclusion, these results demonstrate, for the first time in man, a major effect of a GLP-1RA on regulation of brain glucose metabolism in the absorptive state.


Assuntos
Glicemia , Cérebro/metabolismo , Homeostase/efeitos dos fármacos , Hipoglicemiantes/farmacologia , Peptídeos/farmacologia , Peçonhas/farmacologia , Cérebro/efeitos dos fármacos , Estudos Cross-Over , Diabetes Mellitus/diagnóstico , Método Duplo-Cego , Exenatida , Teste de Tolerância a Glucose , Hemoglobinas Glicadas/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Estado Pré-Diabético
6.
J. bras. nefrol ; 36(1): 80-92, Jan-Mar/2014. tab, graf
Artigo em Inglês | LILACS | ID: lil-704671

RESUMO

The importance of the kidney in glucose homeostasis has been recognized for many years. Recent observations indicating a greater role of renal glucose metabolism in various physiologic and pathologic conditions have rekindled the interest in renal glucose handling as a potential target for the treatment of diabetes. The enormous capacity of the proximal tubular cells to reabsorb the filtered glucose load entirely, utilizing the sodium-glucose co-transporter system (primarily SGLT-2), became the focus of attention. Original studies conducted in experimental animals with the nonspecific SGLT inhibitor phlorizin showed that hyperglycemia after pancreatectomy decreased as a result of forced glycosuria. Subsequently, several compounds with more selective SGLT-2 inhibition properties (“second-generation”) were developed. Some agents made it into pre-clinical and clinical trials and a few have already been approved for commercial use in the treatment of type 2 diabetes. In general, a 6-month period of therapy with SGLT-2 inhibitors is followed by a mean urinary glucose excretion rate of ~80 g/day accompanied by a decline in fasting and postprandial glucose with average decreases in HgA1C ~1.0%. Concomitant body weight loss and a mild but consistent drop in blood pressure also have been reported. In contrast, transient polyuria, thirst with dehydration and occasional hypotension have been described early in the treatment. In addition, a significant increase in the occurrence of uro-genital infections, particularly in women has been documented with the use of SGLT-2 inhibitors. Conclusion: Although long-term cardiovascular, renal and bone/mineral effects are unknown SGLT-2 inhibitors, if used with caution and in the proper patient provide a unique insulin-independent therapeutic option in the management of obese type 2 diabetes patients. .


A importância do rim na homeostase de glicose é reconhecida desde há muitos anos. Observações recentes, indicando um papel maior do metabolismo renal da glicose em várias condições fisiológicas e patológicas, reavivaram o interesse no manuseio renal de glicose como um alvo em potencial para o tratamento do diabetes. A enorme capacidade das células tubulares proximais para reabsorver a carga total de glicose filtrada, utilizando o sistema de co-transporte de sódio e glicose (SGLT), tornou-se o foco de atenção. Estudos originais realizados em animais experimentais com o uso do inibidor não-específico da SGLT florizina, demonstraram que a hiperglicemia após pancreatectomia diminuiu como resultado de glicosúria forçada. Posteriormente, foram desenvolvidas diversas substâncias com propriedades mais seletivas de inibição da SGLT-2 ("segunda geração"). Vários agentes foram usados em ensaios pré-clínicos e clínicos, e alguns já foram aprovados para uso comercial no tratamento da diabetes tipo 2. Em geral, os dados clinicos mostram que um período de 6 meses de tratamento com inibidores da SGLT-2 é seguido por uma taxa de excreção de glicose urinária média de ~ 80 g/dia, acompanhado por uma queda na glicemia de jejum e pós-prandial e com redução média na HbA1C de - 1.0%. Também foram relatados perda concomitante no peso corpóreo e uma leve mas consistente queda da pressão arterial. Em contraste, eventos adversos transitórios como poliúria, sede com desidratação e hipotensão ocasional foram descritos na fase inicial de tratamento. Além disso, um aumento significativo na ocorrência de infecções urogenitais, particularmente em mulheres, foi documentado com o uso de inibidores da SGLT-2. Os efeitos ...


Assuntos
Humanos , /tratamento farmacológico , /metabolismo , Glucose/metabolismo , Reabsorção Renal/efeitos dos fármacos , Proteínas de Transporte de Sódio-Glucose/antagonistas & inibidores
7.
Diabetes Care ; 36(9): 2756-62, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23579178

RESUMO

OBJECTIVE: To assess glucose-lowering mechanisms of sitagliptin (S), metformin (M), and the two combined (M+S). RESEARCH DESIGN AND METHODS: We randomized 16 patients with type 2 diabetes mellitus (T2DM) to four 6-week treatments with placebo (P), M, S, and M+S. After each period, subjects received a 6-h meal tolerance test (MTT) with [(14)C]glucose to calculate glucose kinetics. Fasting plasma glucose (FPG), fasting plasma insulin, C-peptide (insulin secretory rate [ISR]), fasting plasma glucagon, and bioactive glucagon-like peptide (GLP-1) and gastrointestinal insulinotropic peptide (GIP) were measured. RESULTS: FPG decreased from P, 160 ± 4 to M, 150 ± 4; S, 154 ± 4; and M+S, 125 ± 3 mg/dL. Mean post-MTT plasma glucose decreased from P, 207 ± 5 to M, 191 ± 4; S, 195 ± 4; and M+S, 161 ± 3 mg/dL (P < 0.01). The increase in mean post-MTT plasma insulin and in ISR was similar in P, M, and S and slightly greater in M+S. Fasting plasma glucagon was equal (≈ 65-75 pg/mL) with all treatments, but there was a significant drop during the initial 120 min with S 24% and M+S 34% (both P < 0.05) vs. P 17% and M 16%. Fasting and mean post-MTT plasma bioactive GLP-1 were higher (P < 0.01) after S and M+S vs. M and P. Basal endogenous glucose production (EGP) fell from P 2.0 ± 0.1 to S 1.8 ± 0.1 mg/kg · min, M 1.8 ± 0.2 mg/kg · min (both P < 0.05 vs. P), and M+S 1.5 ± 0.1 mg/kg · min (P < 0.01 vs. P). Although the EGP slope of decline was faster in M and M+S vs. S, all had comparable greater post-MTT EGP inhibition vs. P (P < 0.05). CONCLUSIONS: M+S combined produce additive effects to 1) reduce FPG and postmeal plasma glucose, 2) augment GLP-1 secretion and ß-cell function, 3) decrease plasma glucagon, and 4) inhibit fasting and postmeal EGP compared with M or S monotherapy.


Assuntos
Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/tratamento farmacológico , Inibidores da Dipeptidil Peptidase IV/uso terapêutico , Hipoglicemiantes/uso terapêutico , Metformina/uso terapêutico , Pirazinas/uso terapêutico , Triazóis/uso terapêutico , Glicemia/metabolismo , Peptídeo C/sangue , Jejum/sangue , Polipeptídeo Inibidor Gástrico/sangue , Peptídeo 1 Semelhante ao Glucagon/sangue , Humanos , Insulina/sangue , Fosfato de Sitagliptina
8.
Am J Physiol Cell Physiol ; 302(4): C652-7, 2012 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-22094332

RESUMO

To investigate the role of insulin signaling pathways in migration, proliferation, and inflammation of vascular smooth muscle cells (VSMCs), we examined the expression of active components of the phosphatidyl inositol 3 (PI-3) kinase (p-Akt) and mitogen-activated protein kinase (MAPK) (p-Erk) in primary cultures of VSMCs from human coronary arteries. VSMCs were treated in a dose-response manner with insulin (0, 1, 10, and 100 nM) for 20 min, and Akt and Erk phosphorylation were measured by Western blot analysis. In separate experiments, we evaluated the effect of 200 µM palmitate, in the presence and absence of 8 µM pioglitazone, on insulin-stimulated (100 nM for 20 min) Akt and Erk phosphorylation. The phosphorylation of Akt and Erk in VSMCs exhibited a dose dependency with a three- to fourfold increase, respectively, at the highest dose (100 nM). In the presence of palmitate, insulin-induced Akt phosphorylation was completely abolished, and there was a threefold increase in p-Erk. With addition of pioglitazone, the phosphorylation of Akt by insulin remained unchanged, whereas insulin-stimulated Erk phosphorylation was reduced by pioglitazone. These data in VSMCs indicate that high palmitate decreases insulin-stimulated Akt phosphorylation and stimulates MAPK, whereas preexposure peroxisome proliferator-activated receptor-γ agonist pioglitazone preserves Akt phosphorylation and simultaneously attenuates MAPK signaling. Our results suggest that metabolic and mitogenic insulin signals have different sensitivity, are independently regulated, and may play a role in arterial smooth muscle cells migration, proliferation, and inflammation in conditions of acute hyperinsulinemia.


Assuntos
Inflamação/metabolismo , Insulina/metabolismo , Músculo Liso Vascular/fisiologia , Miócitos de Músculo Liso/fisiologia , Transdução de Sinais/efeitos dos fármacos , Tiazolidinedionas/farmacologia , Comunicação Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Movimento Celular/fisiologia , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , MAP Quinases Reguladas por Sinal Extracelular/genética , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Regulação da Expressão Gênica , Humanos , Hiperinsulinismo/metabolismo , Hipoglicemiantes/farmacologia , Insulina/farmacologia , Músculo Liso Vascular/citologia , Músculo Liso Vascular/efeitos dos fármacos , Miócitos de Músculo Liso/citologia , Miócitos de Músculo Liso/efeitos dos fármacos , Receptores Ativados por Proliferador de Peroxissomo/agonistas , Receptores Ativados por Proliferador de Peroxissomo/genética , Receptores Ativados por Proliferador de Peroxissomo/metabolismo , Fosforilação/efeitos dos fármacos , Pioglitazona , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/fisiologia
9.
Am J Physiol Endocrinol Metab ; 299(5): E794-801, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20739506

RESUMO

NF-κB is a transcription factor that controls the gene expression of several proinflammatory proteins. Cell culture and animal studies have implicated increased NF-κB activity in the pathogenesis of insulin resistance and muscle atrophy. However, it is unclear whether insulin-resistant human subjects have abnormal NF-κB activity in muscle. The effect that exercise has on NF-κB activity/signaling also is not clear. We measured NF-κB DNA-binding activity and the mRNA level of putative NF-κB-regulated myokines interleukin (IL)-6 and monocyte chemotactic protein-1 (MCP-1) in muscle samples from T2DM, obese, and lean subjects immediately before, during (40 min), and after (210 min) a bout of moderate-intensity cycle exercise. At baseline, NF-κB activity was elevated 2.1- and 2.7-fold in obese nondiabetic and T2DM subjects, respectively. NF-κB activity was increased significantly at 210 min following exercise in lean (1.9-fold) and obese (2.6-fold) subjects, but NF-κB activity did not change in T2DM. Exercise increased MCP-1 mRNA levels significantly in the three groups, whereas IL-6 gene expression increased significantly only in lean and obese subjects. MCP-1 and IL-6 gene expression peaked at the 40-min exercise time point. We conclude that insulin-resistant subjects have increased basal NF-κB activity in muscle. Acute exercise stimulates NF-κB in muscle from nondiabetic subjects. In T2DM subjects, exercise had no effect on NF-κB activity, which could be explained by the already elevated NF-κB activity at baseline. Exercise-induced MCP-1 and IL-6 gene expression precedes increases in NF-κB activity, suggesting that other factors promote gene expression of these cytokines during exercise.


Assuntos
Diabetes Mellitus Tipo 2/metabolismo , Exercício Físico/fisiologia , Músculo Esquelético/metabolismo , NF-kappa B/metabolismo , Obesidade/metabolismo , Adulto , Glicemia/metabolismo , Western Blotting , Caspase 8/biossíntese , Caspase 8/genética , Quimiocina CCL2/biossíntese , Quimiocina CCL2/genética , Ácidos Graxos não Esterificados/sangue , Feminino , Humanos , Insulina/sangue , Interleucina-6/biossíntese , Interleucina-6/genética , Masculino , Pessoa de Meia-Idade , Consumo de Oxigênio , RNA Mensageiro/química , RNA Mensageiro/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais
10.
Am J Physiol Endocrinol Metab ; 294(5): E846-52, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18334612

RESUMO

We examined the contributions of insulin secretion, glucagon suppression, splanchnic and peripheral glucose metabolism, and delayed gastric emptying to the attenuation of postprandial hyperglycemia during intravenous exenatide administration. Twelve subjects with type 2 diabetes (3 F/9 M, 44 +/- 2 yr, BMI 34 +/- 4 kg/m2, Hb A(1c) 7.5 +/- 1.5%) participated in three meal-tolerance tests performed with double tracer technique (iv [3-3H]glucose and oral [1-14C]glucose): 1) iv saline (CON), 2) iv exenatide (EXE), and 3) iv exenatide plus glucagon (E+G). Acetaminophen was given with the mixed meal (75 g glucose, 25 g fat, 20 g protein) to monitor gastric emptying. Plasma glucose, insulin, glucagon, acetaminophen concentrations and glucose specific activities were measured for 6 h post meal. Post-meal hyperglycemia was markedly reduced (P < 0.01) in EXE (138 +/- 16 mg/dl) and in E+G (165 +/- 12) compared with CON (206 +/- 15). Baseline plasma glucagon ( approximately 90 pg/ml) decreased by approximately 20% to 73 +/- 4 pg/ml in EXE (P < 0.01) and was not different from CON in E+G (81 +/- 2). EGP was suppressed by exenatide [231 +/- 9 to 108 +/- 8 mg/min (54%) vs. 254 +/- 29 to189 +/- 27 mg/min (26%, P < 0.001, EXE vs. CON] and partially reversed by glucagon replacement [247 +/- 15 to 173 +/- 18 mg/min (31%)]. Oral glucose appearance was 39 +/- 4 g in CON vs. 23 +/- 6 g in EXE (P < 0.001) and 15 +/- 5 g in E+G, (P < 0.01 vs. CON). The glucose retained within the splanchnic bed increased from approximately 36g in CON to approximately 52g in EXE and to approximately 60g in E+G (P < 0.001 vs. CON). Acetaminophen((AUC)) was reduced by approximately 80% in EXE vs. CON (P < 0.01). We conclude that exenatide infusion attenuates postprandial hyperglycemia by decreasing EGP (by approximately 50%) and by slowing gastric emptying.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Hiperglicemia/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Peptídeos/uso terapêutico , Período Pós-Prandial/efeitos dos fármacos , Período Pós-Prandial/fisiologia , Peçonhas/uso terapêutico , Acetaminofen/sangue , Adulto , Analgésicos não Narcóticos/sangue , Glicemia/metabolismo , Diabetes Mellitus Tipo 2/sangue , Exenatida , Feminino , Esvaziamento Gástrico/efeitos dos fármacos , Glucagon/sangue , Teste de Tolerância a Glucose , Humanos , Hiperglicemia/sangue , Insulina/sangue , Masculino , Pessoa de Meia-Idade , Triglicerídeos/sangue
11.
Diabetes ; 56(3): 836-48, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17327455

RESUMO

Activation of AMP-activated protein kinase (AMPK) by exercise induces several cellular processes in muscle. Exercise activation of AMPK is unaffected in lean (BMI approximately 25 kg/m(2)) subjects with type 2 diabetes. However, most type 2 diabetic subjects are obese (BMI >30 kg/m(2)), and exercise stimulation of AMPK is blunted in obese rodents. We examined whether obese type 2 diabetic subjects have impaired exercise stimulation of AMPK, at different signaling levels, spanning from the upstream kinase, LKB1, to the putative AMPK targets, AS160 and peroxisome proliferator-activated receptor coactivator (PGC)-1alpha, involved in glucose transport regulation and mitochondrial biogenesis, respectively. Twelve type 2 diabetic, eight obese, and eight lean subjects exercised on a cycle ergometer for 40 min. Muscle biopsies were done before, during, and after exercise. Subjects underwent this protocol on two occasions, at low (50% Vo(2max)) and moderate (70% Vo(2max)) intensities, with a 4-6 week interval. Exercise had no effect on LKB1 activity. Exercise had a time- and intensity-dependent effect to increase AMPK activity and AS160 phosphorylation. Obese and type 2 diabetic subjects had attenuated exercise-stimulated AMPK activity and AS160 phosphorylation. Type 2 diabetic subjects had reduced basal PGC-1 gene expression but normal exercise-induced increases in PGC-1 expression. Our findings suggest that obese type 2 diabetic subjects may need to exercise at higher intensity to stimulate the AMPK-AS160 axis to the same level as lean subjects.


Assuntos
Diabetes Mellitus Tipo 2/metabolismo , Exercício Físico/fisiologia , Complexos Multienzimáticos/metabolismo , Músculo Esquelético/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Transdução de Sinais , Quinases Proteína-Quinases Ativadas por AMP , Proteínas Quinases Ativadas por AMP , Adulto , Aminoácido Oxirredutases/metabolismo , Glicemia/metabolismo , Diabetes Mellitus Tipo 2/fisiopatologia , Feminino , Proteínas Ativadoras de GTPase/metabolismo , Glicogênio/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Fator 1 Nuclear Respiratório/metabolismo , Nucleotídeos/metabolismo , Obesidade/metabolismo , Obesidade/fisiopatologia , Fosforilação , Proteínas Proto-Oncogênicas c-akt/metabolismo , Fatores de Tempo , Fatores de Transcrição/metabolismo
12.
Endocr Pract ; 8(5): 378-80, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-15251841

RESUMO

OBJECTIVE: To report an unusual case of hyperthyroidism from Graves' disease that was coexistent with malignant struma ovarii. METHODS: We summarize the clinical history, physical findings, laboratory data, imaging studies, pathologic features, and treatment in a patient with recurrent hyperthyroidism and discuss the incidence of ovarian tumors of various histologic origins, including thyroid tissue (that is, struma ovarii). RESULTS: Five years after diagnosis of Graves' disease and resolution of symptoms with 1 year of antithyroid drug therapy, a 53-year-old woman had recurrence of palpitations, tremors, and weight loss. Results of thyroid function tests showed high total and free thyroxine levels and a low thyrotropin level. Thyroid radioiodine uptake was high (69% at 24 hours). Abdominal ultrasound studies disclosed a cystic mass in the right adnexal area. Total abdominal hysterectomy and bilateral oophorectomy revealed a 7.5-cm cystic right ovary that contained a 1.0-cm struma ovarii with a 0.4-cm nodule of follicular variant papillary thyroid carcinoma within it. The patient was treated with methimazole and radioiodine ablation of the thyroid. Three months later, a massive myocardial infarction resulted in her death. CONCLUSION: The concomitant presence of Graves' disease complicates the management of struma ovarii and raises interesting questions about treatment and prognosis.


Assuntos
Doença de Graves/complicações , Neoplasias Ovarianas/complicações , Estruma Ovariano/complicações , Antitireóideos/uso terapêutico , Feminino , Doença de Graves/tratamento farmacológico , Humanos , Histerectomia , Metimazol/uso terapêutico , Pessoa de Meia-Idade , Neoplasias Ovarianas/patologia , Neoplasias Ovarianas/cirurgia , Ovariectomia , Recidiva , Estruma Ovariano/patologia , Estruma Ovariano/cirurgia , Tiroxina/sangue
13.
Folha méd ; 103(2): 63-6, ago. 1991. tab
Artigo em Inglês | LILACS | ID: lil-176609

RESUMO

The effects of branched chain amino acid (BCAA) and BCAA plus glucose infusions in nitrogen urinary excretion, in a four day postoperative period, was investigated in rabbits. Thirty-two adults rabbits, male (New Zealand) were randomly assigned to four groups: Group I (control) received saline solution (0.98 percent NaCl); Group II received glucose infusion (1 g/Kg/day); Group III received BCAA infusion (1 g/Kg/day) and Group IV reveived BCAA plus glusoce (1 g/Kg/day). During the four days postoperative period all animals were fasted completely. Urinary total nitrogen excretion was calculated on each day. All results were expressed in grams of nitrogen per kilogram of body weight per day +- standard error of the mean (+- SEM). The infusion of BCAA was followed by a significant reduction in urinary nitrogen excretion when compared to both glucose and saline controls. This nitrogen sparing effect of BCAA infusion during postoperative period was observed in all four days following surgical procedures. Glucose infusion alone also induced a decrease in urinary nitrogen excretion during the four days postoperative period when compared to saline control group. The infusion of BCAA plus glucose was followed by a slight, but significant reduction in urinary nitrogen loss when compared to glucose saline controls. However, the nitrogen excretion in urine after BCAA plus glucose infusion was significantly higher than the nitrogen loss in urine of all animals receiving BCAA alone. We concluded that the nitrogen sparing effect following the infusion of BCAA plus glucose was less pronounced than nitrogen sparing effect of BCAA infusion alone


Assuntos
Animais , Coelhos , Aminoácidos de Cadeia Ramificada/uso terapêutico , Glucose/uso terapêutico , Nitrogênio/metabolismo , Nutrição Parenteral , Cuidados Pós-Operatórios
14.
Arq. bras. med ; 63(3): 231-5, maio-jun. 1988. tab
Artigo em Português | LILACS | ID: lil-71415

RESUMO

O Laboratório Universitário Rodolpho Albino (LURA) da Universidade Federal Fluminense (UFF) vem desenvolvendo uma soluçäo de hidrolisado ácido de caseína com material, matéria-prima e tecnologia inteiramente nacionais. Neste trabalho de validade receberam, durante 166 dias, um gotejamento naso-enteral de uma mistura nutritiva contendo a soluçäo de hidrolisado ácido de caseína LURA-UFF como única fonte proteíca da dieta. Todos os pacientes hospitalizados por traumatismo crânio-encefálico, pancreatite aguda, hipertensäo arterial complicada, fístulas digestivas e neoplasias receberam suporte nutricional como coadjuvante do tratamento clínico ou cirúrgico. Com exceçäo de um paciente com diarréia, todos os demais pacientes demonstraram uma boa tolerância digestiva e näo apresentaram sinais de reaçäo clínica ao produto. Apesar de elevada osmolaridade total de algumas misturas nutritivas, näo se verificou nenhuma complicaçäo clínica. O exame microbiológico das amostras e o pH final da soluçäo estiveram dentro de padröes aceitáveis. Nosso trabalho, porém enfatiza a necessidade de cuidados especiais com os cateteres enterais, a infusäo e o armazenamento da mistura nutritiva final. A demonstraçäo da validade clínica e a avaliaçäo nutricional, em andamento, do hidrolisado ácido de caseína LURA-UFF para uso em nutriçäo enteral hospitalar representa uma conquista porque amplia a disponibilidade de soluçöes nutritivas e, principalmente, por introduzir um produto inteiramente brasileiro, econômico, prático e eficiente. Nossos resultados também provam que a integraçäo e o desenvolvimento de pesquisas interdepartamentais na UFF beneficiam a comunidade


Assuntos
Humanos , Caseínas , Nutrição Enteral , Hidrolisados de Proteína
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