RESUMO
mpkCCDc14 cells, a polarized epithelial cell line derived from mouse kidney cortical collecting ducts, are known to express the vasopressin V2 receptor (V2R) and aquaporin-2 (AQP2) that are responsive to vasopressin. However, a low abundance of the endogenous AQP2 protein in the absence of vasopressin and heterogeneity of AQP2 protein abundance among the cultured cells may limit the further application of the cell line in AQP2 studies. To overcome the limitation, we aimed to establish mpkCCDc14 cells constitutively expressing V2R and AQP2 via CRISPR/Cas9-mediated genome engineering technology (i.e., V2R-AQP2 cells). 3'- and 5'-Junction PCR revealed that the V2R-AQP2 expression cassette with a long insert size (~2.2 kb) was correctly integrated. Immunoblotting revealed the expression of products of integrated Aqp2 genes. Cell proliferation rate and dDAVP-induced cAMP production were not affected by the knock-in of Avpr2 and Aqp2 genes. The AQP2 protein abundance was significantly higher in V2R-AQP2 cells compared with control mpkCCDc14 cells in the absence of dDAVP and the integrated AQP2 was detected. Immunocytochemistry demonstrated that V2R-AQP2 cells exhibited more homogenous and prominent AQP2 labeling intensity in the absence of dDAVP stimulation. Moreover, prominent AQP2 immunolabeling (both AQP2 and pS256-AQP2) in the apical domain of the genome-edited cells was observed in response to dDAVP stimulation, similar to that in the unedited control mpkCCDc14 cells. Taken together, mpkCCDc14 cells constitutively expressing V2R and AQP2 via genome engineering could be exploited for AQP2 studies.
Assuntos
Aquaporina 2 , Túbulos Renais Coletores , Camundongos , Animais , Aquaporina 2/metabolismo , Desamino Arginina Vasopressina/metabolismo , Túbulos Renais Coletores/metabolismo , Vasopressinas/metabolismo , Membrana Celular/metabolismoRESUMO
BACKGROUND: Diarrhea is the increase in the excretion of human water; meanwhile, fisetin, a bioactive flavonol molecule, is widely used in the treatment/prevention of gastrointestinal disorders. The purpose of this study is to investigate the anti-diarrheal activity of fisetin by restoring kidney function, antioxidant activity, inflammatory markers, Na+/K+-ATPase level, apoptosis, and protein content in diarrheal rats. METHODS: A total of 36 male rats were distributed into two groups (18 rats/group): normal and diarrheal. The normal group was further divided into three subgroups (6 rats/subgroup): Control, fisetin, and desmopressin drug subgroups, consisting of normal rats orally treated once a day for 4 weeks with 1 mL distilled water, 50 mg/kg fisetin, and 1 mg/kg desmopressin drug, respectively. A lactose diet containing 35% lactose was fed to the normal rats for a month. The diarrheal rats were also divided into three subgroups (6 rats/subgroup): diarrheal rats, diarrheal rats + fisetin, and diarrheal rats + desmopressin drug groups, whereby the diarrheal rats were orally treated once a day for 4 weeks with 1 mL distilled water, 50 mg/kg fisetin, and 1 mg/kg desmopressin drug, respectively. RESULTS: Fisetin significantly decreased serum urea (41.20 ± 2.6-29.74 ± 2.65), creatinine (1.43 ± 0.05-0.79 ± 0.06), and urinary volume (1.30 ± 0.41-0.98 ± 0.20), while significantly increasing kidney weight (0.48 ± 0.03-0.67 ± 0.07), sodium, potassium, and chloride balance in both serum and urine. Fisetin significantly increased the antioxidant activity (superoxide dismutase (1170 ± 40-3230 ± 50), glutathione peroxidase (365 ± 18-775 ± 16), catalase (0.09 ± 0.03-0.14 ± 0.06), and nicotinamide adenine dinucleotide phosphate hydrogen (NADPH) oxidase activity (8.6 ± 1.31-10.5 ± 1.25), while significantly decreasing malondialdehyde (19.38 ± 0.54-9.54 ± 0.83), conjugated dienes (1.86 ± 0.24-1.64 ± 0.19), and oxidative index (0.62 ± 0.04-0.54 ± 0.05)), alongside the inflammatory markers (tumor necrosis factor-α (65.2 ± 2.59-45.3 ± 2.64), interleukin-1ß, interleukin-6 (107 ± 4.5-56.1 ± 7.2), and interleukin-10) in the diarrheal rats to values approaching the control values. Fisetin also restored the Na+/K+-ATPase level, apoptosis, protein content, and kidney architecture in diarrheal rats to be near the control group. CONCLUSIONS: Fisetin treated diarrhea in rats by restoring kidney function, antioxidant activity, inflammatory markers, apoptosis, proteome content, and histology.
Assuntos
Antioxidantes , Desamino Arginina Vasopressina , Humanos , Ratos , Masculino , Animais , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Antioxidantes/metabolismo , Desamino Arginina Vasopressina/metabolismo , Lactose/metabolismo , Ratos Sprague-Dawley , Rim/metabolismo , Rim/patologia , Estresse Oxidativo , Flavonóis/metabolismo , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Apoptose , Diarreia/tratamento farmacológico , Diarreia/metabolismo , Diarreia/patologia , Adenosina Trifosfatases/metabolismo , Água/metabolismoRESUMO
Water homeostasis is tightly regulated by the kidneys via the process of urine concentration. During reduced water intake, the antidiuretic hormone arginine vasopressin (AVP) binds to the vasopressin receptor type II (V2R) in the kidney to enhance countercurrent multiplication and medullary osmolality, and increase water reabsorption via aquaporin-2 (AQP2) water channels. The importance of this AVP, V2R, and AQP2 axis is highlighted by low urine osmolality and polyuria in people with various water balance disorders, including nephrogenic diabetes insipidus (NDI). ELF5 and nuclear factor of activated T cells 5 (NFAT5) are two transcription factors proposed to regulate Aqp2 expression, but their role is poorly defined. Here we generated two novel mouse lines with principal cell (PC)-specific deletion of ELF5 or NFAT5 and phenotyped them in respect to renal water handling. ELF5-deficient mice (ELF5PC-KO ) had a very mild phenotype, with no clear differences in AQP2 abundance, and mild differences in renal water handling and maximal urinary concentrating capacity. In contrast, NFAT5 (NFAT5PC-KO ) mice had significantly higher water intake and their 24 h urine volume was almost 10-fold greater than controls. After challenging with dDAVP or 8 h water restriction, NFAT5PC-KO mice were unable to concentrate their urine, demonstrating that they suffer from NDI. The abundance of AQP2, other AQPs, and the urea transporter UT-A1 were greatly decreased in NFAT5PC-KO mice. In conclusion, NFAT5 is a major regulator of not only Aqp2 gene transcription, but also other genes important for water homeostasis and its absence leads to the development of NDI.
Assuntos
Diabetes Insípido Nefrogênico , Diabetes Mellitus , Túbulos Renais Coletores , Fatores de Transcrição/metabolismo , Animais , Aquaporina 2/genética , Aquaporina 2/metabolismo , Arginina Vasopressina/metabolismo , Desamino Arginina Vasopressina/metabolismo , Diabetes Insípido Nefrogênico/genética , Diabetes Insípido Nefrogênico/metabolismo , Diabetes Mellitus/metabolismo , Fator V/metabolismo , Túbulos Renais Coletores/metabolismo , Camundongos , Receptores de Vasopressinas/genética , Receptores de Vasopressinas/metabolismo , Linfócitos T/metabolismo , Fatores de Transcrição/genética , Vasopressinas/metabolismo , Água/metabolismoRESUMO
PURPOSE: To clarify the characteristics of Cushing's disease (CD) patients who respond to the desmopressin (DDAVP) test and its underlying mechanisms. METHODS: Forty-seven patients with CD who underwent DDAVP testing were included. Patients were divided into two groups: DDAVP test (+) (adrenocorticotropic hormone [ACTH] levels increased by ≥ 1.5-fold during the DDAVP test) and DDAVP test (-) (ACTH levels increased by < 1.5-fold). AVP receptor expression levels in these tumors were quantified using quantitative RT-PCR and immunohistochemistry. AVP receptor promoter activity was analyzed using a dual-luciferase reporter assay system. RESULTS: Females (96.9%) and USP8 mutants (85.7%) were more prevalent in the DDAVP test (+) than in the DDAVP test (-). Indeed, the ACTH and cortisol responsiveness to DDAVP was greater in USP8 mutation positive tumors than that in USP8 wild type tumors (3.0-fold vs. 1.3-fold, 1.6-fold vs. 1.1-fold, respectively). Responsiveness to DDAVP was correlated with the expression levels of AVPR1B, but not with those of AVPR2. Comparably, Avpr1b promoter activity was enhanced by the overexpression of mutant USP8 compared to the wild type. CONCLUSIONS: We found that the responsiveness of ACTH to DDAVP in CD was greater in tumors with USP8 mutations. The present data suggest that USP8 mutations upregulate the AVPR1B promoter activity. Additionally, we showed that the DDAVP test can predict the presence of USP8 mutations.
Assuntos
Desamino Arginina Vasopressina , Endopeptidases , Complexos Endossomais de Distribuição Requeridos para Transporte , Hipersecreção Hipofisária de ACTH , Receptores de Vasopressinas , Ubiquitina Tiolesterase , Hormônio Adrenocorticotrópico/metabolismo , Desamino Arginina Vasopressina/análise , Desamino Arginina Vasopressina/metabolismo , Endopeptidases/genética , Endopeptidases/metabolismo , Complexos Endossomais de Distribuição Requeridos para Transporte/genética , Complexos Endossomais de Distribuição Requeridos para Transporte/metabolismo , Feminino , Humanos , Hidrocortisona/metabolismo , Mutação , Hipersecreção Hipofisária de ACTH/genética , Hipersecreção Hipofisária de ACTH/metabolismo , Regiões Promotoras Genéticas , Receptores de Vasopressinas/genética , Ubiquitina Tiolesterase/genética , Ubiquitina Tiolesterase/metabolismoRESUMO
Desmopressin (dDAVP) is the best characterized analogue of vasopressin, the endocrine regulator of water balance endowed with potent vasoconstrictive effects. Despite the use of dDAVP in clinical practice, ranging from the treatment of nephrogenic diabetes insipidus to bleeding disorders, much remains to be understood about the impact of the drug on endothelial phenotype. The aim of this study was, thus, to evaluate the effects of desmopressin on the viability and function of human pulmonary microvascular endothelial cells (HLMVECs). The results obtained demonstrate that the vasopressor had no cytotoxic effect on the endothelium; similarly, no sign of endothelial activation was induced by dDAVP, indicated by the lack of effect on the expression of inflammatory cytokines and adhesion molecules. Conversely, the drug significantly stimulated the production of nitric oxide (NO) and the expression of the inducible isoform of nitric oxide synthase, NOS2/iNOS. Since the intracellular level of cAMP also increased, we can hypothesize that NO release is consequent to the activation of the vasopressin receptor 2 (V2R)/guanylate cyclase (Gs)/cAMP axis. Given the multifaceted role of NOS2-deriving NO for many physio-pathological conditions, the meanings of these findings in HLMVECs appears intriguing and deserves to be further addressed.
Assuntos
Desamino Arginina Vasopressina , Óxido Nítrico , Desamino Arginina Vasopressina/metabolismo , Desamino Arginina Vasopressina/farmacologia , Células Endoteliais , Endotélio Vascular/metabolismo , Humanos , Pulmão/metabolismo , Óxido Nítrico/metabolismoRESUMO
Human neurohormone vasopressin (AVP) is synthesized in overlapping regions in the hypothalamus. It is mainly known for its vasoconstricting abilities, and it is responsible for the regulation of plasma osmolality by maintaining fluid homeostasis. Over years, many attempts have been made to modify this hormone and find AVP analogues with different pharmacological profiles that could overcome its limitations. Non-peptide AVP analogues with low molecular weight presented good affinity to AVP receptors. Natural peptide counterparts, found in animals, are successfully applied as therapeutics; for instance, lypressin used in treatment of diabetes insipidus. Synthetic peptide analogues compensate for the shortcomings of AVP. Desmopressin is more resistant to proteolysis and presents mainly antidiuretic effects, while terlipressin is a long-acting AVP analogue and a drug recommended in the treatment of varicose bleeding in patients with liver cirrhosis. Recently published results on diverse applications of AVP analogues in medicinal practice, including potential lypressin, terlipressin and ornipressin in the treatment of SARS-CoV-2, are discussed.
Assuntos
Tratamento Farmacológico da COVID-19 , Diabetes Insípido/prevenção & controle , SARS-CoV-2/efeitos dos fármacos , Vasopressinas/uso terapêutico , Animais , Antidiuréticos/química , Antidiuréticos/metabolismo , Antidiuréticos/uso terapêutico , COVID-19/epidemiologia , COVID-19/virologia , Desamino Arginina Vasopressina/química , Desamino Arginina Vasopressina/metabolismo , Desamino Arginina Vasopressina/uso terapêutico , Diabetes Insípido/metabolismo , Hemostáticos/química , Hemostáticos/metabolismo , Hemostáticos/uso terapêutico , Humanos , Lipressina/química , Lipressina/metabolismo , Lipressina/uso terapêutico , Estrutura Molecular , Ornipressina/química , Ornipressina/metabolismo , Ornipressina/uso terapêutico , Pandemias/prevenção & controle , SARS-CoV-2/metabolismo , SARS-CoV-2/fisiologia , Terlipressina/química , Terlipressina/metabolismo , Terlipressina/uso terapêutico , Vasopressinas/química , Vasopressinas/metabolismoRESUMO
BACKGROUND: The way by which 1-deamino-8-D-arginine vasopressin (DDAVP) acts on platelets remains unclear. Data from the literature tend to show that there is no definite effect on platelet activation, but recent work has suggested that a subtype of platelets, activated by the combined action of collagen and thrombin, was triggered by DDAVP. Moreover, platelet microparticles (PMPs), which have been shown to be procoagulant, have rarely been studied in this context. The goal of this study was to analyze the effects of DDAVP on PMPs' release through platelet activation. METHODS: Fifteen out of 18 consecutive patients undergoing a therapeutic test with DDAVP were included. They were suffering from factor VIII deficiency or from von Willebrand disease. The expression of P-selectin and PAC-1 binding on platelets and the numbers of circulating PMPs were evaluated ex vivo before and after DDAVP infusion. Peripheral blood was collected on CTAD to limit artifactual platelet activation. RESULTS: DDAVP induced a significant decrease of platelet counts and volume. Only small changes of P-selectin expression and PAC-1 binding were observed. Considering PMPs, two populations of patients could be defined, respectively, with (120%, n = 6) or without (21%, n = 7) an increase of PMPs after DDAVP. The decrease in platelet counts and volume remained significant in the group of responders. CONCLUSION: This study shows that DDAVP induces the generation/release of PMPs in some patients with factor VIII deficiency and von Willebrand disease 1 hour after DDAVP infusion.
Assuntos
Hemofilia A , Doenças de von Willebrand , Arginina Vasopressina/metabolismo , Arginina Vasopressina/farmacologia , Plaquetas/metabolismo , Desamino Arginina Vasopressina/metabolismo , Desamino Arginina Vasopressina/farmacologia , Humanos , Selectina-P/metabolismo , Selectina-P/farmacologia , Ativação Plaquetária , Fator de von Willebrand/metabolismoRESUMO
Peptide drugs face several barriers to oral delivery, including enzymatic degradation in the gastrointestinal tract and low membrane permeability. Importantly, the direct interaction between various biorelevant colloids (i.e., bile salt micelles and bile salt-phospholipid mixed micelles) present in the aqueous gastrointestinal environment and peptide drug molecules has not been studied. In this work, we systematically characterized interactions between a water-soluble model peptide drug, octreotide, and a range of physiologically relevant bile salts in solution. Octreotide membrane flux in pure bile salt solutions and commercially available biorelevant media, i.e., fasted state simulated intestinal fluid (FaSSIF) and fed state simulated intestinal fluid (FeSSIF), was evaluated using a side-by-side diffusion cell equipped with a cellulose dialysis membrane. All seven micellar bile salt solutions as well as FaSSIF and FeSSIF decreased octreotide membrane flux, and dihydroxy bile salts were found to have a much larger effect than trihydroxy bile salts. An inverse relationship between octreotide membrane flux and pancreatic enzymatic stability was also observed; bile salt micelles and bile salt-phospholipid mixed micelles provided a protective effect toward enzymatic degradation and prolonged octreotide half-life in vitro. Diffusion ordered nuclear magnetic resonance (DOSY NMR) spectroscopy and dynamic light scattering (DLS) were used as complementary experimental techniques to confirm peptide-micelle interactions in solution. Experiments were also performed using desmopressin as a second model peptide drug; desmopressin interacted with bile salts in solution, albeit to a lower extent relative to octreotide. The findings described herein demonstrate that amphiphilic, water-soluble peptide drugs do interact with bile salts and phospholipids in solution, with an effect on peptide membrane flux and enzymatic stability. Correspondingly, oral peptide drug absorption and bioavailability may be impacted.
Assuntos
Ácidos e Sais Biliares/metabolismo , Desamino Arginina Vasopressina/metabolismo , Mucosa Intestinal/metabolismo , Secreções Intestinais/metabolismo , Octreotida/metabolismo , Disponibilidade Biológica , Celulose , Coloides/metabolismo , Desamino Arginina Vasopressina/farmacocinética , Meia-Vida , Absorção Intestinal/efeitos dos fármacos , Membranas Artificiais , Micelas , Octreotida/química , Octreotida/farmacocinética , Pancreatina/metabolismo , Fosfolipídeos/metabolismo , Solubilidade , Soluções , Água/químicaRESUMO
BACKGROUND: The most profound effect of vasopressin on the kidney is to increase water reabsorption through V2-receptor (V2R) stimulation, but there are also data suggesting effects on calcium transport. To address this issue, we have established an isolated perfused kidney model with accurate pressure control, to directly study the effects of V2R stimulation on kidney function, isolated from systemic effects. METHODS: The role of V2R in renal calcium handling was studied in isolated rat kidneys using a new pressure control system that uses a calibration curve to compensate for the internal pressure drop up to the tip of the perfusion cannula. RESULTS: Kidneys subjected to V2R stimulation using desmopressin (DDAVP) displayed stable osmolality and calcium reabsorption throughout the experiment, whereas kidneys not administered DDAVP exhibited a simultaneous fall in urine osmolality and calcium reabsorption. Epithelial sodium channel (ENaC) inhibition using amiloride resulted in a marked increase in potassium reabsorption along with decreased sodium reabsorption. CONCLUSIONS: A stable isolated perfused kidney model with computer-controlled pressure regulation was developed, which retained key physiological functions. The preparation responds to pharmacological inhibition of ENaC channels and activation of V2R. Using the model, the dynamic effects of V2R stimulation on calcium handling and urine osmolality could be visualised. The study thereby provides evidence for a stimulatory role of V2R in renal calcium reabsorption.
Assuntos
Cálcio/metabolismo , Canais Epiteliais de Sódio/metabolismo , Rim/metabolismo , Receptores de Vasopressinas/metabolismo , Animais , Transporte Biológico , Calibragem , Desamino Arginina Vasopressina/metabolismo , Eletrólitos , Taxa de Filtração Glomerular , Masculino , Concentração Osmolar , Perfusão , Ratos , Ratos Sprague-Dawley , Receptores de Vasopressinas/efeitos dos fármacosRESUMO
BACKGROUND: People with schizophrenia and medical comorbidities are often on multiple medications to manage their symptoms. Herein we present a case of drug-drug interaction (meloxicam and desmopressin), in a patient also on clozapine, that ultimately resulted in hyponatremia and seizure. METHODS: The patient provided consent to have his case published. We searched PubMed and after reviewing 321 articles, 11 were chosen for relevance. RESULTS: Meloxicam enhanced the adverse effect (hyponatremia) of desmopressin and was the likely culprit. CONCLUSIONS: In a patient with higher ADH levels, as in our patient taking desmopressin, the addition of an NSAID could further increase water retention and worsen hyponatremia; indeed, meloxicam was the only new medication added to the patient's regimen, and a drug interaction calculator supports the desmopressin-meloxicam drug-drug interaction as the culprit. We urge clinicians to avoid the use of desmopressin in patients with schizophrenia as this can lead to water intoxication. As meloxicam may worsen desmopressin-induced hyponatremia and could result in seizure, one should avoid using NSAIDs in patients with schizophrenia whom are also prescribed vasopressin/desmopressin. Serum sodium levels should be closely monitored in patients with schizophrenia whose regimen includes desmopressin.
Assuntos
Anti-Inflamatórios não Esteroides/efeitos adversos , Desamino Arginina Vasopressina/efeitos adversos , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/diagnóstico , Hiponatremia/induzido quimicamente , Hiponatremia/diagnóstico , Meloxicam/efeitos adversos , Anti-Inflamatórios não Esteroides/metabolismo , Antidiuréticos/efeitos adversos , Antidiuréticos/metabolismo , Desamino Arginina Vasopressina/metabolismo , Interações Medicamentosas/fisiologia , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/metabolismo , Humanos , Masculino , Meloxicam/metabolismo , Pessoa de Meia-IdadeRESUMO
INTRODUCTION: von Willebrand disease (VWD) is the most common inherited bleeding disorder. Few studies have explored the molecular basis of type 2 VWD. AIM: This study aimed to identify variants associated with type 2 VWD. METHODS: We collected clinical and laboratory data, as well as response to desmopressin and bleeding assessment tool (BAT) score in patients diagnosed with type 2 VWD. We sequenced exons 17, 18, 20 and 28 of the VWF gene. RESULTS: We identified 19 different variants in 40 unrelated patients (47.5%). Most of the variants (84.2%) were found in exon 28. A total of 10/19 variants (52.6%) were identified as "likely causative" in 17/40 patients (42.5%), according to the ISTH-SSC and EAHAD VWF gene mutations databases. Nine variants were initially identified as potentially benign. However, through analyses in silico, four of these variants were reclassified as "likely pathogenic" (Ile1380Val, Asn1435Ser, Ser1486Leu and Tyr1584Cys). Response to desmopressin was associated with three variants: Met740Ile, Arg1597Gln and Tyr1584Cys. Major bleeding was associated with variants related to VWD subtypes 2B and 2M. CONCLUSION: In conclusion, we identified 19 variants, of which 14 are "likely pathogenic" and therefore associated with VWD. We suggest a possible association of pathogenic variants with major bleeding, response to desmopressin and BAT score ≥10, although this requires further confirmation.
Assuntos
Variação Genética , Doença de von Willebrand Tipo 2/genética , Fator de von Willebrand/genética , Adulto , DNA/química , DNA/isolamento & purificação , DNA/metabolismo , Desamino Arginina Vasopressina/metabolismo , Éxons , Feminino , Estudos de Associação Genética , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Análise de Sequência de DNA , Adulto Jovem , Doença de von Willebrand Tipo 2/patologiaRESUMO
The cause of hemophilia A carrier bleeding is not well established. Desmopressin (DDAVP), used clinically to treat or prevent bleeding, can also be used as a medical stress surrogate. This study's objective was to compare the response to DDAVP in hemophilia A carriers with that in normal control patients. Bleeding was assessed by the International Society on Thrombosis and Hemostasis Bleeding Assessment Tool (ISTH-BAT). DDAVP (0.3 µg/kg) was administered either IV or subcutaneously (SC), and blood was drawn at baseline and 1, 2, and 4 hours postadministration. Blood was assessed for factor VIII (FVIII) level, von Willebrand factor (VWF) antigen (VWF:Ag), VWF activity (VWF:RCo or VWF:GPIbM), thromboelastography (TEG), and thrombin generation assay (TGA) at all points, and for VWF propeptide (VWFpp):Ag ratio and ABO blood type at baseline. Carriers were older than control patients (median age, 34 and 21 years, respectively; P = .003) and had higher ISTH-BAT bleeding scores (median bleeding score, 8 and 0, respectively; P = .001). Carriers had a significantly reduced FVIII response to DDAVP compared with control patients (P ≤ .0001). When only carriers with normal baseline FVIII levels (n = 10) were included, carriers maintained a reduced FVIII response (P ≤ .0001). Furthermore, participants with abnormal bleeding scores had a significantly lower FVIII response to DDAVP compared with those with normal bleeding scores (P = .036). Hemophilia A carriers have a lower and less sustained FVIII response to DDAVP, suggesting an impaired ability to respond to hemostatic stress, which contributes to bleeding.
Assuntos
Desamino Arginina Vasopressina/metabolismo , Hemofilia A/complicações , Hemostasia/efeitos dos fármacos , Adulto , Feminino , Hemofilia A/patologia , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
INTRODUCTION: Nocturia is a common urinary condition experienced by both men and women. While desmopressin has historically been utilized to treat conditions such as central diabetes insipidus and primary nocturnal enuresis, there is an increased interest in the use of desmopressin in the management of adult nocturia. Areas covered: This article provides a review on the pathophysiology of nocturia and the clinical outcomes and safety profile of desmopressin in the management of adult nocturnal voiding dysfunction. Expert opinion: To date, desmopressin is the only anti-diuretic hormone that is approved for nocturia. Published literature on desmopressin demonstrate good clinical efficacy in terms of number of nocturnal voids, voided volume and sleep period. Newer formulations have shown that a minimum dosage of 25 µg orally disintegrating sublingual desmopressin appears to be ideal for women, whereas men usually benefit from a minimum of 50 µg. Of the known adverse drug reactions, hyponatremia remains a major concern especially in patients over 65 years of age. At present, long term data on desmopressin remains scarce. Lastly, it is important to stress that no single treatment deals with nocturia in all contexts, and careful assessment remains essential to identify the appropriate and safest treatment in each patient.
Assuntos
Antidiuréticos/uso terapêutico , Desamino Arginina Vasopressina/uso terapêutico , Noctúria/tratamento farmacológico , Antidiuréticos/efeitos adversos , Antidiuréticos/metabolismo , Aquaporinas/metabolismo , Ensaios Clínicos como Assunto , Desamino Arginina Vasopressina/efeitos adversos , Desamino Arginina Vasopressina/metabolismo , Regulamentação Governamental , Humanos , Hiponatremia/etiologia , Noctúria/fisiopatologia , Resultado do TratamentoRESUMO
A reduced von Willebrand factor (VWF) synthesis or survival, or its increased proteolysis, alone or in combination, contributes to the development of von Willebrand disease (VWD).We describe a new, simple mechanistic model for exploring how VWF behaves in well-defined forms of VWD after its 1-desamino-8-D-arginine vasopressin (DDAVP)-induced release from endothelial cells. We aimed to ascertain whether the model can consistently predict VWF kinetic changes. The study involved 9 patients with VWD types Vicenza (a paradigmatic form with a reduced VWF survival), 8 type 2B, 2 type 2A-I, 1 type 2A-II (associated with an increased VWF proteolysis), and 42 normal controls, whose VWF levels were measured after a 24-hour-long DDAVP test. The rate constants considered were: k0, associated with the VWF release phase; k1, illustrating the phase of conversion from high- to low-molecular-weight VWF multimers; and ke, associated with the VWF elimination phase. The amount of VWF released (D) was also measured. ke and D were significantly higher in O than in non-O blood group controls; k1 was also higher, but less markedly so. All the parameters were accelerated in type Vicenza, especially ke (p < 0.0001), which explains the significant reduction in VWF half-life. In types 2B and 2A-II, k1 was one order of magnitude higher than in controls, which explains their loss of large VWF multimers. All parameters except ke were lower in type 2A-I.The proposed mechanistic model clearly describes the altered biochemical pathways in well-characterized VWD, prompting us to suggest that it might help clarify elusive forms of VWD too.
Assuntos
Doenças de von Willebrand/sangue , Fator de von Willebrand/metabolismo , Adulto , Tempo de Sangramento , Desamino Arginina Vasopressina/metabolismo , Fator VIII/metabolismo , Hemostasia , Humanos , Cinética , Pessoa de Meia-Idade , Modelos Teóricos , Proteólise , Resultado do Tratamento , Adulto Jovem , Doenças de von Willebrand/genética , Doenças de von Willebrand/mortalidade , Fator de von Willebrand/genéticaRESUMO
BACKGROUND: Bilateral inferior petrosal sinus sampling (IPSS) with corticotropin-releasing hormone (CRH) is currently the gold standard in the diagnosis of Cushing's disease (CD) and has also been used in tumour lateralization. Our objective was to determine the diagnostic value and lateralization accuracy of IPSS with desmopressin. METHODS: We retrospectively analysed 91 patients with Cushing's syndrome who had either negative findings on pituitary dynamic enhanced magnetic resonance imaging (MRI) or nonsuppressed high-dose dexamethasone suppression tests (HDDST). Thin-slice thoracoabdominal computed tomography (CT) and octreotide receptor imaging of whole body were also negative to rule out ectopic adrenocorticotropin hormone (ACTH) syndrome. All patients went through IPSS with desmopressin. Afterwards, transsphenoidal pituitary surgery, light microscope pathology and immunohistological staining for ACTH were performed in all patients. RESULTS: Diagnosis of CD. Among the 91 patients included, 90 were confirmed with CD, of whom 89 had positive IPSS findings, therefore the sensitivity was 98.9%. The one patient who was negative for CD also had negative IPSS findings, therefore the specificity was 100%. Tumour lateralization. Among the 51 patients who were ultimately diagnosed with CD and whose lateralization by IPSS and surgery was either left or right, 37 had IPSS lateralization in concordance with surgery, therefore the concordance rate was 72.5%. Patients in the concordant group had a higher frequency of right lateralization by surgery. CONCLUSIONS: IPSS with desmopressin is a sensitive approach in the diagnosis of CD and has moderate accuracy in tumour lateralization, making it an alternative choice to IPSS with CRH.
Assuntos
Desamino Arginina Vasopressina/metabolismo , Amostragem do Seio Petroso/métodos , Hipersecreção Hipofisária de ACTH/diagnóstico , Hipersecreção Hipofisária de ACTH/metabolismo , Síndrome de ACTH Ectópico/diagnóstico , Síndrome de ACTH Ectópico/metabolismo , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , SoftwareRESUMO
It has been proposed that a reduction in intracellular calcium causes an increase in intracellular cAMP and PKA activity through stimulation of calcium inhibitable adenylyl cyclase 6 and inhibition of phosphodiesterase 1 (PDE1), the main enzymes generating and degrading cAMP in the distal nephron and collecting duct, thus contributing to the development and progression of autosomal dominant polycystic kidney disease (ADPKD). In zebrafish pde1a depletion aggravates and overexpression ameliorates the cystic phenotype. To study the role of PDE1A in a mammalian system, we used a TALEN pair to Pde1a exon 7, targeting the histidine-aspartic acid dipeptide involved in ligating the active site Zn++ ion to generate two Pde1a null mouse lines. Pde1a mutants had a mild renal cystic disease and a urine concentrating defect (associated with upregulation of PDE4 activity and decreased protein kinase A dependent phosphorylation of aquaporin-2) on a wild-type genetic background and aggravated renal cystic disease on a Pkd2WS25/- background. Pde1a mutants additionally had lower aortic blood pressure and increased left ventricular (LV) ejection fraction, without a change in LV mass index, consistent with the high aortic and low cardiac expression of Pde1a in wild-type mice. These results support an important role of PDE1A in the renal pathogenesis of ADPKD and in the regulation of blood pressure.
Assuntos
Nucleotídeo Cíclico Fosfodiesterase do Tipo 1/metabolismo , Rim Policístico Autossômico Dominante/metabolismo , Rim Policístico Autossômico Dominante/patologia , Animais , Pressão Sanguínea , Peso Corporal , Sistema Cardiovascular/metabolismo , Sistema Cardiovascular/patologia , Sistema Cardiovascular/fisiopatologia , AMP Cíclico/metabolismo , Desamino Arginina Vasopressina/metabolismo , Homozigoto , Rim/metabolismo , Camundongos , Camundongos Knockout , Camundongos Mutantes , Miocárdio/metabolismo , Miocárdio/patologia , Tamanho do Órgão , Fenótipo , Rim Policístico Autossômico Dominante/fisiopatologia , Antígeno Nuclear de Célula em Proliferação/metabolismo , Nucleases dos Efetores Semelhantes a Ativadores de Transcrição/metabolismoRESUMO
Small peptides with a molecular weight of <2kDa represent a performance-enhancing substances. However, in vivo studies with human volunteers are limited because most of these peptides are not approved for human consumption. Thus, relevant in vitro models are a basic tool to study their metabolism for anti-doping purposes. To choose the best in vitro model the biotransformation of growth hormone releasing peptides (GHRPs), Desmopressin and TB-500 was investigated using various in vitro systems. High metabolic activity was observed during incubation of GHRPs and TB-500 with human kidney microsomes (HKM) and liver S9 fraction. Peptides degraded through cleavage of all bonds regardless protective modifications in primary structure. HKM and liver S9 fraction demonstrated enzymatic deamidation activity removing C-terminal amide group from all GHRPs. Fewer metabolites were produced during incubation with human serum. The metabolite pattern obtained with commercially available proteases was poor and included nonspecific hydrolyzed compounds. Thus, the maximum diversity of metabolites was achieved with HKM and liver S9 fraction which makes them the most efficient in vitro model systems for peptides biotransformation study. BIOLOGICAL SIGNIFICANCE: Currently, >60 peptide medicines are FDA approved and marketed in the United States as biopharmaceutical products. Approximately 140 peptide drugs are in clinical trials and about 500 therapeutic peptides in preclinical development. There is an emerging interest in small peptides with a molecular weight of <2kDa, which can be used as doping in modern sport due a wide spectrum of their physiological activity. Most of peptide doping products are not yet approved for human use and some of them undergo preclinical or clinical trials, which complicates the study of metabolism in vivo. The investigation of the metabolism with in vitro methods is an alternative that does not require a human participation and an approval by the Ethics Committee.
Assuntos
Dopagem Esportivo , Rim/metabolismo , Fígado/metabolismo , Microssomos Hepáticos/metabolismo , Oligopeptídeos/metabolismo , Peptídeo Hidrolases/metabolismo , Substâncias para Melhoria do Desempenho/metabolismo , Soro/metabolismo , Animais , Biotransformação , Cromatografia Líquida , Desamino Arginina Vasopressina/metabolismo , Feminino , Humanos , Técnicas In Vitro , Masculino , Espectrometria de Massas , Peptídeo Hidrolases/sangueRESUMO
Liver disease results in complex alterations of all 3 phases of hemostasis. It is now recognized that hemostasis is rebalanced in chronic liver disease. The fall in clotting factor levels is accompanied by a parallel fall in anticoagulant proteins. High von Willebrand factor levels counteract defects in primary hemostasis. Conventional coagulation tests do not fully reflect the derangement in hemostasis and do not accurately predict the risk of bleeding. Global coagulation assays (thrombin generation, thromboelastography) reflect the interaction between procoagulant factors, anticoagulant factors, platelets, and the fibrinolytic system and show promise for assessing bleeding risk and guiding therapy. These assays are not yet commercially approved or validated. Prevention of bleeding should not be aimed at correcting conventional coagulation tests. Thrombopoietin receptor agonists were shown to increase the platelet count in cirrhotic patients undergoing invasive procedures but may increase the risk of thrombosis. Rebalanced hemostasis in liver disease is precarious and may be tipped toward hemorrhage or thrombosis depending on coexisting circumstantial risk factors. Bacterial infection may impair hemostasis in cirrhosis by triggering the release of endogenous heparinoids. There are no evidence-based guidelines for hemostatic therapy of acute hemorrhage in liver disease. There is currently inadequate evidence to support the use of recombinant FVIIa, prothrombin complex concentrates, or tranexamic acid in acute variceal or other hemorrhage.
Assuntos
Transtornos da Coagulação Sanguínea/complicações , Hepatopatias/complicações , Proteínas ADAM/metabolismo , Proteína ADAMTS13 , Antifibrinolíticos/uso terapêutico , Coagulação Sanguínea , Fatores de Coagulação Sanguínea/uso terapêutico , Desamino Arginina Vasopressina/metabolismo , Fator VIIa/uso terapêutico , Fibrinólise , Hemorragia , Hemostasia/efeitos dos fármacos , Humanos , Coeficiente Internacional Normatizado , Plasma , Tempo de Protrombina , Receptores de Trombopoetina/agonistas , Proteínas Recombinantes/uso terapêutico , Fatores de Risco , Tromboelastografia , Trombina/química , Vitamina K/metabolismoRESUMO
P2Y12 receptor (P2Y12-R) signaling is mediated through Gi, ultimately reducing cellular cAMP levels. Because cAMP is a central modulator of arginine vasopressin (AVP)-induced water transport in the renal collecting duct (CD), we hypothesized that if expressed in the CD, P2Y12-R may play a role in renal handling of water in health and in nephrogenic diabetes insipidus. We found P2Y12-R mRNA expression in rat kidney, and immunolocalized its protein and aquaporin-2 (AQP2) in CD principal cells. Administration of clopidogrel bisulfate, an irreversible inhibitor of P2Y12-R, significantly increased urine concentration and AQP2 protein in the kidneys of Sprague-Dawley rats. Notably, clopidogrel did not alter urine concentration in Brattleboro rats that lack AVP. Clopidogrel administration also significantly ameliorated lithium-induced polyuria, improved urine concentrating ability and AQP2 protein abundance, and reversed the lithium-induced increase in free-water excretion, without decreasing blood or kidney tissue lithium levels. Clopidogrel administration also augmented the lithium-induced increase in urinary AVP excretion and suppressed the lithium-induced increase in urinary nitrates/nitrites (nitric oxide production) and 8-isoprostane (oxidative stress). Furthermore, selective blockade of P2Y12-R by the reversible antagonist PSB-0739 in primary cultures of rat inner medullary CD cells potentiated the expression of AQP2 and AQP3 mRNA, and cAMP production induced by dDAVP (desmopressin). In conclusion, pharmacologic blockade of renal P2Y12-R increases urinary concentrating ability by augmenting the effect of AVP on the kidney and ameliorates lithium-induced NDI by potentiating the action of AVP on the CD. This strategy may offer a novel and effective therapy for lithium-induced NDI.
Assuntos
Arginina Vasopressina/metabolismo , Diabetes Insípido Nefrogênico/metabolismo , Túbulos Renais Coletores/metabolismo , Túbulos Renais Coletores/fisiopatologia , Receptores Purinérgicos P2Y12/metabolismo , Animais , Aquaporina 2/análise , Aquaporina 2/efeitos dos fármacos , Aquaporina 2/urina , Arginina Vasopressina/efeitos dos fármacos , Arginina Vasopressina/urina , Clopidogrel , Desamino Arginina Vasopressina/metabolismo , Diabetes Insípido Nefrogênico/induzido quimicamente , Diabetes Insípido Nefrogênico/fisiopatologia , Capacidade de Concentração Renal/efeitos dos fármacos , Medula Renal/química , Túbulos Renais Coletores/química , Lítio , Masculino , Antagonistas do Receptor Purinérgico P2Y/farmacologia , RNA Mensageiro/metabolismo , Ratos , Ratos Brattleboro , Ratos Sprague-Dawley , Receptores Purinérgicos P2Y12/análise , Receptores Purinérgicos P2Y12/genética , Ticlopidina/análogos & derivados , Ticlopidina/farmacologia , Água/metabolismoRESUMO
Peptide hormones represent an emerging class of potential doping agents. Detection of their misuse is difficult due to their short half-life in plasma and rapid elimination. Therefore, investigating their metabolism can improve detectability. Unfortunately, pharmacokinetic studies with human volunteers are often not allowed because of ethical constraints, and therefore alternative models are needed. This study was performed in order to evaluate in vitro models (human liver microsomes and S9 fraction) for the prediction of the metabolism of peptidic doping agents and to compare them with the established models. The peptides that were investigated include desmopressin, TB-500, GHRP-2, GHRP-6, hexarelin, LHRH and leuprolide. Several metabolites were detected for each peptide after incubation with human liver microsomes, S9 fraction, and serum, which all showed endopeptidase and exopeptidase activity. In vitro models from different organs (liver vs. kidney) were compared, but no significant differences were recorded. Deamidation was not observed in any of the models and was therefore evaluated by incubation with α-chymotrypsin. In conclusion, in vitro models are useful tools for forensic and clinical analysts to detect peptidic metabolic markers in biological fluids.