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1.
J Toxicol Sci ; 44(9): 575-584, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31474739

RESUMO

The adrenal gland is the most common toxicological target of drugs within the endocrine system, and inhibition of adrenal steroidogenesis can be fatal in humans. However, methods to evaluate the adrenal toxicity are limited. The aim of the present study was to verify the usefulness of simultaneous measurement of blood levels of multiple adrenal steroids, including precursors, as a method to evaluate drug effects on adrenal steroidogenesis in cynomolgus monkeys. With this aim, physiological and drug-induced changes in blood levels of adrenal steroids, including cortisol, aldosterone, androgen, and their precursors were examined. First, for physiological changes, intraday and interday changes in blood steroid levels were examined in male and female cynomolgus monkeys. The animals showed circadian changes in steroid levels that are similar to those in humans, while interday changes were relatively small in males. Next, using males, changes in blood steroid levels induced by ketoconazole and metyrapone were examined, which suppress adrenal steroidogenesis via inhibition of CYP enzymes. Consistent with rats and humans, both ketoconazole and metyrapone increased the deoxycorticosterone and deoxycortisol levels, probably via CYP11B1 inhibition, and the increase was observed earlier and with greater dynamic range than the changes in cortisol level. Changes in other steroid levels reflecting the drug mechanisms were also observed. In conclusion, this study showed that in cynomolgus monkeys, simultaneous measurement of blood levels of adrenal steroids, including precursors, can be a valuable method to sensitively evaluate drug effects on adrenal steroidogenesis and to investigate the underlying mechanisms.


Assuntos
Glândulas Suprarrenais/efeitos dos fármacos , Glândulas Suprarrenais/metabolismo , Aldosterona/sangue , Aldosterona/metabolismo , Androgênios/sangue , Androgênios/metabolismo , Cromatografia Líquida/métodos , Hidrocortisona/sangue , Hidrocortisona/metabolismo , Cetoconazol/toxicidade , Metirapona/toxicidade , Espectrometria de Massas em Tandem/métodos , Animais , Ritmo Circadiano , Desoxicorticosterona/metabolismo , Feminino , Humanos , Macaca fascicularis , Masculino , Esteroide 11-beta-Hidroxilase/antagonistas & inibidores
2.
J Toxicol Sci ; 44(9): 601-610, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31474741

RESUMO

To verify simultaneous measurement of blood levels of adrenal steroids as a tool to evaluate drug effects on adrenal steroidogenesis, dose- and time-dependent changes in blood levels of corticosterone and its precursors (pregnenolone, progesterone and deoxycorticosterone), as well as their relationship with the pathological changes in the adrenal gland, were examined in rats dosed with ketoconazole (KET). Also examined were whether effects on adrenal steroidogenesis that were not obvious in the blood steroid levels after sole administration of KET could be revealed by post-administration of ACTH, and the correlation between the blood and adrenal steroid levels. Male rats were dosed with 15, 50, or 150 mg/kg of KET for 1 or 7 days with or without ACTH, and the blood and adrenal concentrations of the steroids were measured. KET increased the blood deoxycorticosterone level even at a dose level and time point at which histopathological changes were not obvious. KET-induced changes in blood levels of other steroids were revealed by ACTH, and the blood and adrenal levels were generally correlated especially after ACTH post-administration. Thus, blood levels of adrenal steroids, including precursors, can be a sensitive and early marker of drug effects on the adrenal steroidogenesis that reflect adrenal levels of steroids. The usefulness of the multiple steroid measurement as a method for mechanism investigation of drug effects on the adrenal gland can be further enhanced by ACTH.


Assuntos
Glândulas Suprarrenais/efeitos dos fármacos , Glândulas Suprarrenais/metabolismo , Hormônio Adrenocorticotrópico/farmacologia , Desoxicorticosterona/sangue , Desoxicorticosterona/metabolismo , Cetoconazol/toxicidade , Pregnenolona/sangue , Pregnenolona/metabolismo , Progesterona/sangue , Progesterona/metabolismo , Glândulas Suprarrenais/patologia , Hormônio Adrenocorticotrópico/administração & dosagem , Animais , Cromatografia Líquida , Relação Dose-Resposta a Droga , Masculino , Ratos , Ratos Sprague-Dawley , Espectrometria de Massas em Tandem , Fatores de Tempo
3.
J Vet Intern Med ; 33(5): 2286-2293, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31489708

RESUMO

BACKGROUND: Transient hypothalamic-pituitary-adrenal axis dysfunction occurs in critically ill foals with sepsis and neonatal maladjustment syndrome (NMS). Cortisol is the most commonly measured steroid. However, a complex interaction of various steroid compounds might play a role in pathophysiology of this disorder. OBJECTIVE: To identify steroid compounds present at high concentrations at birth that rapidly and steadily decrease within the first 7 days of life in healthy foals and that might be supportive diagnosis of NMS and other neonatal disorders. ANIMALS: Ten healthy neonatal Quarter Horse foals (5 females and 5 males). METHODS: Prospective study. Blood was collected in heparinized tubes within 30 minutes after birth, and at 12, 24, 48, 72, 96, 120, 144, and 168 hours of age. Plasma was separated and a panel of steroid compounds was analyzed using liquid chromatography-mass spectrometry. A nonlinear regression model was used to determine decay concentrations over time. Confidence intervals (CIs) were calculated and significance was set a P ≤ .05. RESULTS: Five compounds were identified: pregnenolone, progesterone, deoxycorticosterone, dehydroepiandrosterone, and dehydroepiandrosterone sulfate. Pregnenolone and progesterone concentrations rapidly decreased by 24 hours of age and remained low throughout the first 7 days of life. Their half-life (95% CI) was short at 3.7 (3.4, 4.0) and 4.5 (2.8, 6.1) hours, respectively. No statistical differences in the concentrations of these compounds were found between males and females. CONCLUSIONS AND CLINICAL RELEVANCE: Progesterone might be a useful marker for identifying continuous endogenous production of neuroactive steroids in foals with suspected NMS and other neonatal diseases.


Assuntos
Animais Recém-Nascidos/sangue , Cavalos/sangue , Sistema Hipotálamo-Hipofisário/fisiologia , Sistema Hipófise-Suprarrenal/fisiologia , Animais , Desidroepiandrosterona/sangue , Sulfato de Desidroepiandrosterona/sangue , Desoxicorticosterona/sangue , Feminino , Masculino , Pregnenolona/sangue , Progesterona/sangue , Estudos Prospectivos
4.
J Vet Intern Med ; 33(3): 1266-1271, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30865322

RESUMO

BACKGROUND: Lowering the dose of desoxycorticosterone pivalate (DOCP) for the treatment of dogs with primary hypoadrenocorticism (PH) decreases costs and could lead to increased owner motivation to treat their affected dogs. OBJECTIVE: To evaluate the efficacy of a low-dose DOCP treatment protocol in dogs with PH. ANIMALS: Prospective study, 17 client-owned dogs with naturally occurring PH (12 newly diagnosed, 5 previously treated with fludrocortisone acetate [FC]). METHODS: Dogs with newly diagnosed PH were started on 1.5 mg/kg DOCP SC; dogs previously treated with FC were started on 1.0-1.8 mg/kg DOCP SC. Reevaluations took place at regular intervals for a minimum of 3 months and included clinical examination and determination of serum sodium and potassium concentrations. The DOCP dosage was adjusted to obtain an injection interval of 28-30 days and to keep serum electrolyte concentrations within the reference interval. RESULTS: Median (range) follow-up was 16.2 months (4.5-32.3 months). The starting dosage was sufficient in all but 2 dogs and had to be significantly decreased after 2-3 months to a median dosage (range) of 1.1 mg/kg (0.7-1.8). Dogs 3 years of age or younger needed significantly higher dosages compared to older dogs. None of them, however, needed the 2.2 mg/kg DOCP dosage, recommended by the manufacturer. CONCLUSIONS AND CLINICAL IMPORTANCE: A starting dosage of 1.5 mg/kg DOCP is effective in controlling clinical signs and serum electrolyte concentrations in the majority of dogs with PH. An additional dose reduction often is needed to maintain an injection interval of 28-30 days. Young and growing animals seem to need higher dosages.


Assuntos
Doença de Addison/veterinária , Desoxicorticosterona/análogos & derivados , Doenças do Cão/tratamento farmacológico , Mineralocorticoides/administração & dosagem , Doença de Addison/tratamento farmacológico , Doença de Addison/economia , Fatores Etários , Animais , Desoxicorticosterona/administração & dosagem , Desoxicorticosterona/economia , Desoxicorticosterona/uso terapêutico , Doenças do Cão/economia , Cães , Feminino , Masculino , Mineralocorticoides/economia , Mineralocorticoides/uso terapêutico , Potássio/sangue , Estudos Prospectivos , Sódio/sangue
5.
Bratisl Lek Listy ; 120(2): 148-154, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30793620

RESUMO

Alzheimer's disease (AD) is an advanced neurodegenerative disorder greatly accompanied by acetylcholinesterase (AChE) activation and amyloid plaque deposition. Tetrahydrodeoxycorticosterone (THDOC) is an endogenous neurosteroid that is reduced in AD patient according to previous results. It has neuroprotective effects and plays important role in neurological diseases. By considering AChE role in AD, this study investigated THDOC effects on catalytic and non-catalytic functions of the enzyme. Inhibitory effect of THDOC on hydrolytic activity of AChE was confirmed by in vitro assay (IC50 = 5.68 µM). Molecular docking analysis revealed THDOC bound tightly to the catalytic site of enzyme and inhibited substrate binding. According to in vivo experiments, neurosteroid administration causes inhibition of hyper-activated AChE in hippocampus related to rat model of AD. Staining of hippocampus tissue by plaque specific dye approved THDOC reduced plaque numbers and size in AD rats. Histological and immunoblotting experiments showed neurosteroid administration improved neurodegeneration and neuronal damages in AD rats that lead to improved spatial learning ability. Overall this study suggests, THDOC is an endogenous regulator for AChE. By considering pathophysiological and molecular similarities between AD and animal model, our results highlight THDOC as a potential therapeutic strategy in patients suffering from AD or similar cognitive disorders (Fig. 6, Ref. 28). Keywords: tetrahydrodeoxycorticosterone, acetylcholinesterase, non-catalytic function, amyloid plaque deposition, nucleus basalis of Meynert lesioned rats, neurodegeneration.


Assuntos
Acetilcolinesterase , Doença de Alzheimer , Desoxicorticosterona/análogos & derivados , Placa Amiloide , Acetilcolinesterase/efeitos dos fármacos , Doença de Alzheimer/tratamento farmacológico , Animais , Desoxicorticosterona/uso terapêutico , Humanos , Simulação de Acoplamento Molecular , Neurotransmissores , Placa Amiloide/tratamento farmacológico , Ratos
6.
Am J Physiol Renal Physiol ; 316(5): F807-F813, 2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-30759025

RESUMO

Circadian rhythms govern physiological functions and are important for overall health. The molecular circadian clock comprises several transcription factors that mediate circadian control of physiological function, in part, by regulating gene expression in a tissue-specific manner. These connections are well established, but the underlying mechanisms are incompletely understood. The overall goal of this study was to examine the connection among the circadian clock protein Period 1 (Per1), epithelial Na+ channel (ENaC), and blood pressure (BP) using a multipronged approach. Using global Per1 knockout mice on a 129/sv background in combination with a high-salt diet plus mineralocorticoid treatment, we demonstrated that loss of Per1 in this setting is associated with protection from hypertension. Next, we used the ENaC inhibitor benzamil to demonstrate a role for ENaC in BP regulation and urinary Na+ excretion in 129/sv mice. We targeted Per1 indirectly using pharmacological inhibition of Per1 nuclear entry in vivo to demonstrate altered expression of known Per1 target genes as well as a BP-lowering effect in 129/sv mice. Finally, we directly inhibited Per1 via genetic knockdown in amphibian distal nephron cells to demonstrate, for the first time, that reduced Per1 expression is associated with decreased ENaC activity at the single channel level.


Assuntos
Pressão Sanguínea , Ritmo Circadiano , Canais Epiteliais de Sódio/metabolismo , Hipertensão/prevenção & controle , Néfrons/metabolismo , Proteínas Circadianas Period/metabolismo , Amilorida/análogos & derivados , Amilorida/farmacologia , Animais , Anti-Hipertensivos/farmacologia , Pressão Sanguínea/efeitos dos fármacos , Caseína Quinases/antagonistas & inibidores , Caseína Quinases/metabolismo , Ritmo Circadiano/efeitos dos fármacos , Desoxicorticosterona/análogos & derivados , Modelos Animais de Doenças , Bloqueadores do Canal de Sódio Epitelial/farmacologia , Canais Epiteliais de Sódio/efeitos dos fármacos , Canais Epiteliais de Sódio/genética , Hipertensão/genética , Hipertensão/metabolismo , Hipertensão/fisiopatologia , Masculino , Camundongos da Linhagem 129 , Camundongos Knockout , Mineralocorticoides , Natriurese , Néfrons/efeitos dos fármacos , Proteínas Circadianas Period/antagonistas & inibidores , Proteínas Circadianas Period/deficiência , Proteínas Circadianas Period/genética , Pirimidinas/farmacologia , Cloreto de Sódio na Dieta , Fatores de Tempo , Xenopus
7.
Toxicol Sci ; 168(1): 252-263, 2019 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-30535411

RESUMO

Many glucocorticoid receptor (GR) agonists have been detected in waste and surface waters domestically and around the world, but the way a mixture of these environmental compounds may elicit a total glucocorticoid activity response in water samples remains unknown. Therefore, we characterized 19 GR ligands using a CV1 cell line transcriptional activation assay applicable to water quality monitoring. Cells were treated with individual GR ligands, a fixed ratio mixture of full or partial agonists, or a nonequipotent mixture with full and partial agonists. Efficacy varied (48.09%-102.5%) and potency ranged over several orders of magnitude (1.278 × 10-10 to 3.93 × 10-8 M). Concentration addition (CA) and response addition (RA) mixtures models accurately predicted equipotent mixture responses of full agonists (r2 = 0.992 and 0.987, respectively). However, CA and RA models assume mixture compounds produce full agonist-like responses, and therefore they overestimated observed maximal efficacies for mixtures containing partial agonists. The generalized concentration addition (GCA) model mathematically permits < 100% maximal responses, and fell within the 95% confidence interval bands of mixture responses containing partial agonists. The GCA, but not CA and RA, model predictions of nonequipotent mixtures containing both full and partial agonists fell within the same statistical distribution as the observed values, reinforcing the practicality of the GCA model as the best overall model for predicting GR activation. Elucidating the mechanistic basis of GR activation by mixtures of previously detected environmental GR ligands will benefit the interpretation of environmental sample contents in future water quality monitoring studies.


Assuntos
Bioensaio/métodos , Glucocorticoides/metabolismo , Modelos Biológicos , Receptores de Glucocorticoides/agonistas , Receptores de Glucocorticoides/metabolismo , Corticosterona/farmacologia , Desoxicorticosterona/farmacologia , Dexametasona/farmacologia , Relação Dose-Resposta a Droga , Agonismo Parcial de Drogas , Ligantes , Prednisolona/farmacologia , Ativação Transcricional
8.
Horm Mol Biol Clin Investig ; 37(3)2018 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-30398970

RESUMO

Background Although numerous studies have proven that estrogen (Est) has a protective effect on the development of hypertension, more research needs to be done to show its detailed mechanism in a variety of hypertension. The important role of active oxygen species in blood pressure is well defined. We examined whether or not sex hormones change the growth of reactive oxygen species (ROS) in kidneys after central microinjection of angiotensin II (Ang II). Materials and methods Female Wistar rats, 8 weeks old (200 ± 10 g) were used in this study. The animal groups were (1) Sham, (2) Ovariectomy (OVX), (3) Sham-Hypertension (Sham-Hyper), (4) OVX-Hypertension (OVX-Hyper), (5) Sham-Hyper-Est, (6) OVX-Hyper-Est ; (7) Sham-Hyper-Testosterone (Tst) and (8) OVX-Hyper-Tst. Solutions of 1% NaCl and 0.1 KCl were used and desoxycorticostrone (doca-salt) was injected (45 mg/kg) 3 times a week in Hypertension groups. Estradiol and Tst (2 mg/kg and 5 mg/kg ; daily; subcutaneously) for 4 weeks. Ang II (50 µM, 5 µL) was microinjected by intracerebroventricular ( i.c.v.) infusion and malondialdehyde (MDA) and thiol in the kidneys were measured. Results MDA in the kidneys was increased by Ang II and doca-salt treatments. Both estradiol and Tst decreased the kidney's MDA. The level of thiol was higher in Hyper groups and reversed after treatment with estradiol and Tst. Conclusions Our findings suggest that central effect of Ang II on blood pressure and kidney disease is accompanied with increased levels of oxidative stress in the kidneys. Indeed sex hormones change the ROS level in the kidneys after central microinjection of Ang II. .


Assuntos
Angiotensina II/farmacologia , Desoxicorticosterona/farmacologia , Estradiol/farmacologia , Rim/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Testosterona/farmacologia , Androgênios/farmacologia , Angiotensina II/administração & dosagem , Animais , Desoxicorticosterona/administração & dosagem , Estrogênios/farmacologia , Feminino , Injeções Intraventriculares , Rim/metabolismo , Malondialdeído/metabolismo , Estresse Oxidativo , Ratos , Ratos Wistar
9.
Biochem Pharmacol ; 156: 357-370, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30179588

RESUMO

Hypertension-induced cardiovascular and renal damage can be mediated by activation of the renin-angiotensin-aldosterone system. There are different factors beyond renin-angiotensin-aldosterone system involved in hypertension and renal damage. Inflammation has emerged as an important mediator of hypertension and cardiovascular and kidney damage. Angiotensin-(1-9), a peptide of the renin-angiotensin system, counter-regulates both the physiological and pathological actions of angiotensin II. Recent data has shown that angiotensin-(1-9) protects the heart and blood vessels from adverse cardiovascular remodeling in experimental models of hypertension and/or heart failure and reduces cardiac fibrosis in stroke-prone, spontaneously hypertensive rats. These effects are mediated by the angiotensin II type 2 receptor (AT2R). However, it remains unknown whether angiotensin-(1-9) also has an anti-inflammatory effect. In the present study, we investigate whether angiotensin-(1-9) reduces inflammation and fibrosis in the heart, arteries, and kidney in a DOCA-salt hypertensive model and explore the mechanisms underlying the amelioration of end-organ damage. DOCA-salt hypertensive rats received: a) vehicle, b) angiotensin-(1-9), c) PD123319 (AT2R blocker), d) angiotensin-(1-9) plus A779 (a Mas receptor blocker) or e) angiotensin-(1-9) plus PD123319, and sham rats were used as a control. Our results showed that angiotensin-(1-9) decreased hypertension and increased vasodilation in DOCA-salt hypertensive rats. These actions were partially inhibited by PD123319. Moreover, angiotensin-(1-9) decreased diuresis, fibrosis, and inflammation. These beneficial effects were not mediated by Mas or AT2R blockers. We concluded that angiotensin-(1-9) protects against volume overload-induced hypertensive cardiovascular and kidney damage by decreasing inflammation in the heart, aortic wall, and kidney, through mechanisms independent of the Mas or AT2R.


Assuntos
Angiotensinas/farmacologia , Hipertensão/induzido quimicamente , Inflamação/induzido quimicamente , Nefropatias/induzido quimicamente , Renina/metabolismo , Actinas/genética , Actinas/metabolismo , Animais , Aorta/citologia , Aorta/efeitos dos fármacos , Aorta/patologia , Desoxicorticosterona/toxicidade , Hipertensão/tratamento farmacológico , Inflamação/tratamento farmacológico , Nefropatias/tratamento farmacológico , Masculino , Ratos , Ratos Sprague-Dawley
10.
Pharmacol Rep ; 70(4): 684-687, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29920420

RESUMO

BACKGROUND: Zinc (Zn) is a micronutrient and essential element of life and its deficiency causes severe disorders of numerous body systems, such as immune, reproductive and central nervous system. Zinc supplementation affects wound healing and sexual development. The interactions between drugs administration and Zn level in tissues are not fully understood. The aim of the study was to demonstrate differences in Zn content in teeth of laboratory animals that have undergone pharmacological tests. METHODS: The teeth were extracted from laboratory animals after chronic administration of a non-steroidal anti-inflammatory drug (8-[4-[4-(4-chlorophenyl) piperazine-1-sulfonylphenyl]]-1-propylxanthine), a steroid anti-inflammatory drug (deoxycorticosterone) and an anti-cancer drug (oxaliplatin used acutely). The method of flame atomic absorption spectrometry was used to determine the Zn content in the teeth of the laboratory animals. RESULTS: Based on the studies conducted, the administration of the anti-inflammatory drug PSB-603 and deoxycorticosterone results in an increase in Zn accumulation in the teeth of laboratory animals, which may be indicative of the effect of anti-inflammatory drugs on the metabolism of this bioelement. Oxaliplatin has the opposite effect, after which the level of the measured bioelement in the teeth of mice depended on the administered dose. This level was on average 21.0-28.1% lower than the Zn level in the teeth of the control group. Anti-cancer drugs may interfere with Zn accumulation in the teeth and cause the removal of this metal from bone tissue. CONCLUSION: It can be assumed that the Zn content in teeth can be markedly affected by the drugs that were administrated to animals.


Assuntos
Animais de Laboratório/metabolismo , Desoxicorticosterona/efeitos adversos , Compostos Organoplatínicos/efeitos adversos , Dente/efeitos dos fármacos , Dente/metabolismo , Zinco/metabolismo , Animais , Relação Dose-Resposta a Droga , Masculino , Camundongos , Oxaliplatina , Ratos
11.
Gen Comp Endocrinol ; 265: 22-30, 2018 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-29886079

RESUMO

Clear evidence for a physiological role of the mineralocorticoid-like hormone 11-deoxycorticosterone (DOC) and the mineralocorticoid receptor (MR) in fish is still lacking. Efforts to demonstrate an osmoregulatory role for this hormone has so far not been conclusive, while a few scattered studies have indicated a role for DOC in development and reproduction. In this study, we investigate the onset of de novo DOC synthesis in parallel with endogenous corticosteroid receptor mRNA production from fertilization to the swim-up stage in rainbow trout. Whole egg DOC content decreased from fertilization until hatching followed by an increase to pre-fertilization levels just after hatching. Onset of de novo transcription of corticosteroid receptor mRNA's was observed shortly after the midblastula transition; initially glucocorticoid receptor 2 (GR2) followed by MR and then GR1. Non-invasive introduction of DOC or cortisol at fertilization resulted in altered corticosteroid receptor regulation and accelerated hatching date, suggesting a regulatory role in trout ontogenesis of both hormones through MR signaling pathway. The results presented in this study suggest a possible physiological role of the DOC-MR signaling pathway during fish ontogenesis, at fertilization and just after hatching.


Assuntos
Desoxicorticosterona/metabolismo , Hidrocortisona/metabolismo , Oncorhynchus mykiss/embriologia , Oncorhynchus mykiss/metabolismo , Receptores de Esteroides/metabolismo , 11-beta-Hidroxiesteroide Desidrogenase Tipo 2/genética , 11-beta-Hidroxiesteroide Desidrogenase Tipo 2/metabolismo , Animais , Desoxicorticosterona/farmacologia , Embrião não Mamífero/efeitos dos fármacos , Embrião não Mamífero/metabolismo , Desenvolvimento Embrionário/efeitos dos fármacos , Desenvolvimento Embrionário/genética , Feminino , Fertilização/efeitos dos fármacos , Regulação da Expressão Gênica no Desenvolvimento , Masculino , Óvulo/efeitos dos fármacos , Óvulo/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transdução de Sinais/efeitos dos fármacos
12.
Gen Physiol Biophys ; 37(2): 205-211, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29593126

RESUMO

Absence epilepsy is a generalized nonconvulsive type of epilepsy that is characterized by spike-wave discharges (SWD) with a frequency of 2.5-4 Hz in the EEG. The activation of the GABAergic system in central nervous system suppresses convulsive seizures but exacerbates absence seizures. Endogenous neuroactive steroids such as 3α-hydroxy-5α-pregnan-20-one (3α,5α-THPROG; allopregnanolone) and 3α,21-dihydroxy-5α-pregnan-20-one (3α,5α-THDOC, allotetrahydrodeoxycorticosteron) are GABA-A receptor-positive allosteric modulators. Finasteride which is a 5α-reductase inhibitor can selectively block the synthesis of endogenous steroids. In this study, we compared the effects of endogenous steroids (THPROG and THDOC) on SWD by using finasteride-treated Wistar Albino Glaxo from Rijswijk (WAG/Rij) rats as a model of absence epilepsy. Wistar (WIS-THPROG and WIS-THDOC) and WAG/Rij (WAG-THPROG and WAG-THDOC) rats were divided into 4 groups (n = 8). After stereotactic surgical procedures, all rats were prepared for direct cortical EEG measurement. Following finasteride administration to each group, THPROG was administered to WIS-THPROG and WAG-THPROG groups, and THDOC to WIS-THDOC and WAG-THDOC groups intraperitoneally. While there was no any SWD activity detected in WIS-THPROG and WIS-THDOC groups, a significant increase in SWD count in WAG-THPROG (p = 0.012) and in WAG-THDOC (p = 0.012), and in SWD total duration in WAG-THPROG (p = 0.012) and WAG-THDOC groups (p = 0.011) were observed after steroid injection. No difference between the efficacy of THPROG and THDOC on absence seizures in WAG/Rij rats was observed.


Assuntos
Encéfalo/efeitos dos fármacos , Epilepsia Tipo Ausência , Pregnanolona/farmacologia , Animais , Desoxicorticosterona/análogos & derivados , Desoxicorticosterona/farmacologia , Modelos Animais de Doenças , Eletroencefalografia/efeitos dos fármacos , Masculino , Ratos , Ratos Wistar
13.
Mol Neurobiol ; 55(11): 8509-8521, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29560580

RESUMO

Tonic inhibition mediated by ambient levels of GABA that activate extrasynaptic GABAA receptors emerges as an essential factor that tunes neuronal network excitability in vitro and shapes behavioral responses in vivo. To address the role of neuromodulatory transmitter systems on this type of inhibition, we employed patch clamp recordings in mouse amygdala slice preparations. Our results show that the current amplitude of tonic inhibition (Itonic) in projection neurons of the basal amygdala (BA) is increased by preincubation with the neurosteroid THDOC, while the benzodiazepine diazepam is ineffective. This suggests involvement of THDOC sensitive δ subunit containing GABAA receptors in mediating tonic inhibition. Moreover, we provide evidence that the neuromodulatory transmitters NE, 5HT, and ACh strongly enhance spontaneous IPSCs as well as Itonic in the BA. As the increase in frequency, amplitude, and charge of sIPSCs by these neuromodulatory transmitters strongly correlated with the amplitude of Itonic, we conclude that spill-over of synaptic GABA leads to activation of Itonic and thereby to dampening of amygdala excitability. Since local injection of THDOC, as a positive modulator of tonic inhibition, into the BA interfered with the expression of contextual fear memory, our results point to a prominent role of Itonic in fear learning.


Assuntos
Tonsila do Cerebelo/metabolismo , Inibição Neural/fisiologia , Neurotransmissores/metabolismo , Terminações Pré-Sinápticas/metabolismo , Antagonistas de Receptores Adrenérgicos alfa 1/farmacologia , Tonsila do Cerebelo/efeitos dos fármacos , Animais , Desoxicorticosterona/análogos & derivados , Desoxicorticosterona/farmacologia , Medo/efeitos dos fármacos , Ativação do Canal Iônico/efeitos dos fármacos , Masculino , Memória/efeitos dos fármacos , Camundongos Endogâmicos C57BL , Inibição Neural/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Nicotina/farmacologia , Norepinefrina/farmacologia , Terminações Pré-Sinápticas/efeitos dos fármacos , Serotonina/farmacologia , Ácido gama-Aminobutírico/metabolismo
14.
J Biol Chem ; 293(8): 3013-3027, 2018 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-29301936

RESUMO

Neurosteroids are endogenous sterols that potentiate or inhibit pentameric ligand-gated ion channels (pLGICs) and can be effective anesthetics, analgesics, or anti-epileptic drugs. The complex effects of neurosteroids on pLGICs suggest the presence of multiple binding sites in these receptors. Here, using a series of novel neurosteroid-photolabeling reagents combined with top-down and middle-down mass spectrometry, we have determined the stoichiometry, sites, and orientation of binding for 3α,5α-pregnane neurosteroids in the Gloeobacter ligand-gated ion channel (GLIC), a prototypic pLGIC. The neurosteroid-based reagents photolabeled two sites per GLIC subunit, both within the transmembrane domain; one site was an intrasubunit site, and the other was located in the interface between subunits. By using reagents with photoreactive groups positioned throughout the neurosteroid backbone, we precisely map the orientation of neurosteroid binding within each site. Amino acid substitutions introduced at either site altered neurosteroid modulation of GLIC channel activity, demonstrating the functional role of both sites. These results provide a detailed molecular model of multisite neurosteroid modulation of GLIC, which may be applicable to other mammalian pLGICs.


Assuntos
Proteínas de Bactérias/metabolismo , Desoxicorticosterona/análogos & derivados , Canais Iônicos de Abertura Ativada por Ligante/metabolismo , Modelos Moleculares , Neurotransmissores/metabolismo , Pregnanos/metabolismo , Substituição de Aminoácidos , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Sítios de Ligação , Cianobactérias , Desoxicorticosterona/química , Desoxicorticosterona/metabolismo , Hidroxilação , Cinética , Canais Iônicos de Abertura Ativada por Ligante/química , Canais Iônicos de Abertura Ativada por Ligante/genética , Ligantes , Conformação Molecular , Simulação de Acoplamento Molecular , Mutagênese Sítio-Dirigida , Neurotransmissores/química , Marcadores de Fotoafinidade/química , Mutação Puntual , Pregnanos/química , Conformação Proteica , Domínios e Motivos de Interação entre Proteínas , Mapeamento de Interação de Proteínas , Multimerização Proteica , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo
15.
Gen Comp Endocrinol ; 258: 184-193, 2018 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-28837788

RESUMO

This study aims to shed light on corticosteroid regulation of stress in teleost fish with focus on the corticosteroid signalling system. The role of the mineralocorticoid-like hormone 11-deoxycorticosterone (DOC) in fish is still enigmatic, as is the function of the mineralocorticoid receptor, MR. Low plasma DOC levels and ubiquitous tissue distribution of MR question the physiological relevance of the mineralocorticoid-axis. Furthermore, the particular purpose of each of the three corticosteroid receptors in fish, the glucocorticoid receptors, GR1 and GR2, and the MR, is still largely unknown. Therefore we investigate the regulation of cortisol and DOC in plasma and mRNA levels of MR, GR1 and GR2 in the HPI-axis tissues (hypothalamus, pituitary and interrenal gland) during a detailed confinement stress time-course. Here we show a sustained up-regulation of plasma DOC levels during a confinement stress time-course. However, the low DOC levels compared to cortisol measured in the plasma do not favour an activity of DOC through MR receptors. Furthermore, we show differential contribution of the CRs in regulation and control of HPI axis activity following confinement stress. Judged by the variation of mRNA levels negative feedback regulation of cortisol release occurs on the level of the pituitary via MR and on the level of the interrenal gland via GR2. Finally, asa significant effect of confinement stress on CR expressions was observed in the pituitary gland, we completed this experiment by demonstrating that corticosteroid receptors (GR1, GR2 and MR) are co-expressed in the ACTH cells located in the adenohypophysis. Overall, these data suggest the involvement of these receptors in the regulation of the HPI axis activity by cortisol.


Assuntos
Desoxicorticosterona/metabolismo , Sistema Hipotálamo-Hipofisário/metabolismo , Glândula Inter-Renal/metabolismo , Oncorhynchus mykiss/metabolismo , Receptores de Glucocorticoides/metabolismo , Receptores de Mineralocorticoides/metabolismo , Estresse Fisiológico/fisiologia , Criação de Animais Domésticos , Animais , Desoxicorticosterona/sangue , Feminino , Hidrocortisona/sangue , Masculino , Oncorhynchus mykiss/fisiologia , Receptores de Glucocorticoides/genética , Receptores de Mineralocorticoides/genética , Receptores de Esteroides/metabolismo , Restrição Física , Transdução de Sinais/genética , Transdução de Sinais/fisiologia , Estresse Fisiológico/genética
16.
Artigo em Inglês | MEDLINE | ID: mdl-29223774

RESUMO

The comparative effects of cortisol and 11-deoxycorticosterone (DOC), two major corticosteroids in fish, have yet received little attention in teleosts. We evaluated the proteomic and immune responses of Eurasian perch to chronic corticosteroid treatments. We implanted immature perch with cortisol (80mg/kg) or DOC (4mg/kg) and measured the proportions of blood leucocytes, immune indices in the plasma, spleen and liver (complement and lysozyme activity, total immunoglobulin and immune gene expression in the tissues) and differential proteome expression (corticosteroid versus control) in the liver and the spleen on days 2, 4 and 14 post-treatment. Implantation of cortisol decreased the ratio of blood leucocytes and depressed Ig levels in both organs while DOC modulated the proportion of leucocyte sub-populations (increase in lymphocytes and decrease in granulocytes). In contrast, the innate humoral immunity was not strongly influenced by any of corticosteroid implants. The only immune parameter that was significantly affected was lysozyme, after DOC treatment. A number of proteins were differentially regulated by these hormones and some were identified in the liver (21 for cortisol and 8 for DOC) and in the spleen (10 for cortisol and 10 for DOC). None of the proteins was directly linked to immunity, except the natural killer enhancing factor, which was repressed by cortisol in the spleen. Our results also confirm that the proteins involved in energetic and glucose metabolism are affected by corticosteroids. Furthermore, these corticosteroids differently regulate immune status in Eurasian perch and they primarily impact leucocytes, as opposed to innate immune function.


Assuntos
Desoxicorticosterona/administração & dosagem , Proteínas de Peixes/metabolismo , Hidrocortisona/administração & dosagem , Imunidade Inata/efeitos dos fármacos , Percas/metabolismo , Percas/fisiologia , Proteômica , Animais , Proteínas do Sistema Complemento/metabolismo , Desoxicorticosterona/farmacologia , Metabolismo Energético , Expressão Gênica/efeitos dos fármacos , Glucose/metabolismo , Hidrocortisona/sangue , Hidrocortisona/farmacologia , Leucócitos/imunologia , Fígado/efeitos dos fármacos , Fígado/imunologia , Muramidase/metabolismo , Percas/imunologia , Baço/efeitos dos fármacos , Baço/imunologia , Estresse Fisiológico/efeitos dos fármacos
17.
Auton Neurosci ; 210: 34-43, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29246398

RESUMO

In peripheral tissues, aldosterone alters expression of multiple genes, including the clock gene Period 1 (Per1), 11 beta-hydroxysteroid dehydrogenase-2 (11-HSD2), and α-ENAC, the epithelial sodium channel subunit. We evaluated the impact of chronic aldosterone exposure (DOCA) and salt intake on nocturnal changes in gene expression in the male Sprague Dawley rat brain. Additionally, genes associated with the orexin (ORX) system were also evaluated based on the role of this neuropeptide in arousal, feeding and hypertension and an interconnection with Per1 expression. DOCA/salt treatment increased saline intake primarily at night, elevated arterial pressure and lowered heart rate. In the medulla oblongata, DOCA/salt upregulated Per1, 11-HSD2, and α-ENAC expression independent of time of day, but did not change ORX receptor type 1 (ORX-R1) or type 2 (ORX-R2) expression. ORX-R1, and ORX-R2 expression in the medulla did however correlate with Per1 expression following DOCA/salt treatment but not in controls. In the hypothalamus, DOCA/salt treatment upregulated Per1, ORX-A, and ORX-R2 expression, in general, and Per1 and ORX-A expression at night. ORX-A, ORX-R1 and ORX-R2 expression in the hypothalamus correlated with Per1 expression following DOCA/salt but not in controls. These findings demonstrate for the first time that DOCA/salt hypertension modulates ORX gene expression in the brain and suggest that changes in expression in the ORX system may occur directly or indirectly via aldosterone-induced changes in Per1 expression. Our findings also build on emerging evidence that monitoring gene expression during both the day and night is critical to understanding the role of specific genes in hypertension.


Assuntos
Desoxicorticosterona/farmacologia , Hipertensão/patologia , Hipotálamo/efeitos dos fármacos , Bulbo/efeitos dos fármacos , Orexinas/metabolismo , Proteínas Circadianas Period/metabolismo , Regulação para Cima/efeitos dos fármacos , Análise de Variância , Animais , Pressão Sanguínea/efeitos dos fármacos , Ritmo Circadiano/fisiologia , Modelos Animais de Doenças , Frequência Cardíaca/efeitos dos fármacos , Hipertensão/induzido quimicamente , Hipotálamo/metabolismo , Masculino , Bulbo/metabolismo , Receptores de Orexina/genética , Receptores de Orexina/metabolismo , Orexinas/genética , Proteínas Circadianas Period/genética , Ratos , Ratos Sprague-Dawley , Cloreto de Sódio/farmacologia
18.
Sci Rep ; 7(1): 17737, 2017 12 18.
Artigo em Inglês | MEDLINE | ID: mdl-29255279

RESUMO

Kidney biopsy is considered the golden criterion for diagnosing the etiology of kidney disease but accompanied by non-negligible complications. We explored the possibility of using urinary microRNA (miRNA) as a non-invasive biomarker for hypertensive kidney injury. We assessed differential miRNA expressions in the kidneys and urine of hypertensive mice with kidney injury induced by deoxycorticosterone acetate (DOCA)-salt compared to the controls. DOCA-salt treatment significantly increased renal tubular lesions from day 2 and mRNA expression of fibrosis-related genes from day 4 compared to the controls, respectively. Urinary albumin and N-acetyl-beta-D-glucosaminidase was significantly increased on day 8 compared to the controls. Array results showed that 20 out of 585 miRNAs were highly expressed in the kidneys and significantly increased on day 8 compared to the controls, including miR-21, miR-146b, miR-155 and miR-132, which were confirmed by real-time polymerase chain reaction and were significantly higher from day 4. The miR-21/creatinine in the urine from day 4 was significantly higher than that of the controls and was detected earlier than urinary albumin. In conclusion, we have identified urinary miR-21 that correlates with histopathological lesions and functional markers of kidney damage to facilitate a potential noninvasive detection for hypertensive kidney injury.


Assuntos
Fibrose/genética , Hipertensão Renal/genética , MicroRNAs/genética , Acetilglucosaminidase/análise , Acetilglucosaminidase/urina , Lesão Renal Aguda/patologia , Animais , Biomarcadores/metabolismo , Biomarcadores/urina , Creatinina/análise , Creatinina/urina , Desoxicorticosterona/metabolismo , Fibrose/metabolismo , Hipertensão/metabolismo , Hipertensão Renal/metabolismo , Rim/lesões , Rim/metabolismo , Túbulos Renais/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , MicroRNAs/fisiologia , Sistema Urinário/metabolismo
19.
J Vet Intern Med ; 31(6): 1643-1648, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29024024

RESUMO

BACKGROUND: Thyrotropin (TSH) can be increased in humans with primary hypoadrenocorticism (HA) before glucocorticoid treatment. Increase in TSH is a typical finding of primary hypothyroidism and both diseases can occur concurrently (Schmidt's syndrome); therefore, care must be taken in assessing thyroid function in untreated human patients with HA. OBJECTIVE: Evaluate whether alterations in cTSH can be observed in dogs with HA in absence of primary hypothyroidism. ANIMALS: Thirty dogs with newly diagnosed HA, and 30 dogs in which HA was suspected but excluded based on a normal ACTH stimulation test (controls) were prospectively enrolled. METHODS: cTSH and T4 concentrations were determined in all dogs and at selected time points during treatment (prednisolone, fludrocortisone, or DOCP) in dogs with HA. RESULTS: cTSH concentrations ranged from 0.01 to 2.6 ng/mL (median 0.29) and were increased in 11/30 dogs with HA; values in controls were all within the reference interval (range: 0.01-0.2 ng/dL; median 0.06). There was no difference in T4 between dogs with increased cTSH (T4 range 1.0-2.1; median 1.3 µg/dL) compared to those with normal cTSH (T4 range 0.5-3.4, median 1.4 µg/dL; P=0.69) and controls (T4 range 0.3-3.8, median 1.8 µg/dL; P=0.35). After starting treatment, cTSH normalized after 2-4 weeks in 9 dogs and after 3 and 4 months in 2 without thyroxine supplementation. CONCLUSIONS AND CLINICAL RELEVANCE: Evaluation of thyroid function in untreated dogs with HA can lead to misdiagnosis of hypothyroidism; treatment with glucocorticoids for up to 4 months can be necessary to normalize cTSH.


Assuntos
Doença de Addison/veterinária , Doenças do Cão/diagnóstico , Tireotropina/sangue , Doença de Addison/sangue , Doença de Addison/diagnóstico , Doença de Addison/tratamento farmacológico , Animais , Desoxicorticosterona/análogos & derivados , Desoxicorticosterona/uso terapêutico , Doenças do Cão/sangue , Doenças do Cão/tratamento farmacológico , Cães , Feminino , Glucocorticoides/uso terapêutico , Hipotireoidismo/veterinária , Masculino , Prednisolona/uso terapêutico , Tiroxina/sangue
20.
Toxicol Pathol ; 45(6): 756-763, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-29046138

RESUMO

The aim of this study was to evaluate the usefulness of simultaneous measurement of plasma steroids, including precursors, for the evaluation of drug effects on adrenal steroidogenesis in vivo. Plasma concentrations of corticosterone and its precursors were examined in rats dosed with compounds that affect adrenal steroidogenesis via different modes of action as well as the relationships of the changes with blood chemistry and adrenal histopathology. Male rats were dosed with tricresyl phosphate, aminoglutethimide, trilostane (TRL), metyrapone (MET), ketoconazole (KET), or mifepristone for 7 days. In the TRL, MET, and KET groups, precursor levels were markedly increased, while there were no significant changes in the corticosterone level, suggesting that the precursors are more sensitive biomarkers to detect the effect on adrenal steroidogenesis. Also, the precursors with increased levels were those that are normally metabolized by the inhibited enzymes, reflecting the modes of action of the compounds. In addition, different patterns of changes were observed in blood chemistry and histopathology, supporting the mechanism suggested by the steroid changes. These results show that simultaneous measurement of plasma steroids, including precursors, can be a valuable method to sensitively evaluate drug effects on adrenal steroidogenesis and to investigate the underlying mechanisms.


Assuntos
Glândulas Suprarrenais/efeitos dos fármacos , Corticosterona/biossíntese , Corticosterona/sangue , Monitoramento de Medicamentos/métodos , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/sangue , Glândulas Suprarrenais/metabolismo , Glândulas Suprarrenais/patologia , Animais , Peso Corporal/efeitos dos fármacos , Desoxicorticosterona/sangue , Masculino , Tamanho do Órgão/efeitos dos fármacos , Preparações Farmacêuticas/administração & dosagem , Preparações Farmacêuticas/metabolismo , Pregnenolona/sangue , Progesterona/sangue , Ratos , Ratos Sprague-Dawley
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