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1.
Gen Comp Endocrinol ; 265: 97-105, 2018 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-28919448

RESUMO

The brain synthesizes steroids de novo from cholesterol, which are called neurosteroids. Based on extensive studies on neurosteroids over the past thirty years, it is now accepted that neurosteroidogenesis in the brain is a conserved property across vertebrates. However, the formation of bioactive neurosteroids in the brain is still incompletely elucidated in vertebrates. In fact, we recently identified 7α-hydroxypregnenolone (7α-OH PREG) as a novel bioactive neurosteroid stimulating locomotor behavior in the brain of several vertebrates. The follow-up studies have demonstrated that the stimulatory action of brain 7α-OH PREG on locomotor behavior is mediated by the dopaminergic system across vertebrates. More recently, we have further demonstrated that the pineal gland, an endocrine organ located close to the brain, is a major site of the formation of bioactive neurosteroids. In addition to the brain, the pineal gland actively produces 7α-OH PREG de novo from cholesterol as a major pineal neurosteroid that acts on the brain to control locomotor rhythms. This review summarizes the identification, biosynthesis and mode of action of brain and pineal 7α-OH PREG, a new bioactive neurosteroid regulating locomotor behavior, across vertebrates.


Assuntos
17-alfa-Hidroxipregnenolona/análogos & derivados , Comportamento Animal/efeitos dos fármacos , Encéfalo/metabolismo , Atividade Motora/efeitos dos fármacos , Glândula Pineal/metabolismo , Vertebrados/metabolismo , 17-alfa-Hidroxipregnenolona/química , 17-alfa-Hidroxipregnenolona/farmacologia , Animais , Encéfalo/efeitos dos fármacos , Atividade Motora/fisiologia , Glândula Pineal/efeitos dos fármacos
2.
Gen Comp Endocrinol ; 224: 96-103, 2015 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-26141146

RESUMO

Reproductive behavior in amphibians, as in other vertebrate animals, is under the control of multiple hormonal substances. Prolactin (PRL), arginine vasotocin (AVT), androgen, and 7α-hydroxypregnenolone (7α-OH PREG), four such substances with hormonal activity, are known to be involved in the expression of the tail vibration behavior which is the initial step of courtship performed by the male newt, Cynops pyrrhogaster. As current information on the interaction(s) between these hormones in terms of eliciting tail vibration behavior is limited, we have investigated whether the decline of expression of tail vibration behavior due to suppression of the activity of any one of these hormones can be restored by supplying any one of the other three hormones exogenously. Expression of the behavior was determined in terms of incidence (% of test animals exhibiting the behavior) and frequency (number of times that the behavior was repeated during the test period). Neither PRL nor androgen restored the decline in the incidence and frequency of the tail vibration behavior caused by the suppression of the activity of any one of other three hormones. AVT completely restored both the anti-PRL antibody-induced and flutamide (an androgen receptor antagonist)-induced, but not ketoconazole (an inhibitor of the steroidogenic CYP enzymes)-induced decline in the incidence and frequency of the tail vibration behavior. The neurosteroid, 7α-OH PREG, failed to restore flutamide-induced decline in the incidence and frequency of the behavior. However, it was able to restore both anti-PRL antibody-induced and AVT receptor antagonist-induced decline in the incidence, but not in the frequency of the behavior. In another experiment designed to see the activity of hormones enhancing the frequency of the tail vibration behavior, AVT was revealed to be more potent than 7α-OH PREG. The role of each hormonal substance in determining the expression of the tail vibration behavior was discussed based on the results.


Assuntos
17-alfa-Hidroxipregnenolona/análogos & derivados , Androgênios/farmacologia , Prolactina/farmacologia , Salamandridae/fisiologia , Comportamento Sexual Animal/efeitos dos fármacos , Cauda/efeitos dos fármacos , Vasotocina/farmacologia , Vibração , 17-alfa-Hidroxipregnenolona/farmacologia , Animais , Corte , Masculino , Neurotransmissores/farmacologia , Cauda/inervação , Vasoconstritores/farmacologia
3.
Front Neuroendocrinol ; 34(3): 179-89, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23685042

RESUMO

Biologically active steroids synthesized in the central and peripheral nervous systems are termed neurosteroids. However, the biosynthetic pathways leading to the formation of neurosteroids are still incompletely elucidated. 7α-Hydroxypregnenolone, a novel bioactive neurosteroid stimulating locomotor activity, has been recently identified in the brain of newts and quail. Subsequently, the mode of action and regulation of biosynthesis of 7α-hydroxypregnenolone have been determined. Moreover, recent studies on birds have demonstrated that the pineal gland, an endocrine organ located close to the brain, is an important site of production of neurosteroids de novo from cholesterol. 7α-Hydroxypregnenolone is a major pineal neurosteroid that stimulates locomotor activity in juvenile chickens, connecting light-induced gene expression with locomotion. This review summarizes the advances in our understanding of the identification, mode of action and regulation of biosynthesis of brain and pineal 7α-hydroxypregnenolone, a potent stimulator of locomotor activity.


Assuntos
17-alfa-Hidroxipregnenolona/análogos & derivados , Encéfalo/metabolismo , Locomoção/efeitos dos fármacos , Atividade Motora/efeitos dos fármacos , Glândula Pineal/metabolismo , 17-alfa-Hidroxipregnenolona/metabolismo , Animais , Encéfalo/fisiologia , Corticosterona/fisiologia , Feminino , Luz , Masculino , Melatonina/fisiologia , Atividade Motora/fisiologia , Prolactina/fisiologia , Salamandridae
4.
Gen Comp Endocrinol ; 205: 11-22, 2014 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-24704561

RESUMO

Bargmann-Scharrer's discovery of "neurosecretion" in the first half of the 20th century has since matured into the scientific discipline of neuroendocrinology. Identification of novel neurohormones, such as neuropeptides and neurosteroids, is essential for the progress of neuroendocrinology. Our studies over the past two decades have significantly broadened the horizons of this field of research by identifying novel neuropeptides and neurosteroids in vertebrates that have opened new lines of scientific investigation in neuroendocrinology. We have established de novo synthesis and functions of neurosteroids in the brain of various vertebrates. Recently, we discovered 7α-hydroxypregnenolone (7α-OH PREG), a novel bioactive neurosteroid that acts as a key regulator for inducing locomotor behavior by means of the dopaminergic system. We further discovered that the pineal gland, an endocrine organ located close to the brain, is an important site of production of neurosteroids de novo from cholesterol (CHOL). The pineal gland secretes 7α-OH PREG and 3α,5α-tetrahydroprogesterone (3α,5α-THP; allopregnanolone) that are involved in locomotor rhythms and neuronal survival, respectively. Subsequently, we have demonstrated their mode of action and functional significance. This review summarizes the discovery of these novel neurosteroids and its contribution to the progress of neuroendocrinology.


Assuntos
Neuroendocrinologia , Neuropeptídeos/metabolismo , Neurotransmissores/metabolismo , Glândula Pineal/metabolismo , 17-alfa-Hidroxipregnenolona/análogos & derivados , 17-alfa-Hidroxipregnenolona/metabolismo , Animais , Humanos , Atividade Motora/fisiologia
5.
Proc Natl Acad Sci U S A ; 108(12): 4864-9, 2011 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-21383147

RESUMO

The circadian clock is phase-delayed or -advanced by light when given at early or late subjective night, respectively. Despite the importance of the time-of-day-dependent phase responses to light, the underlying molecular mechanism is poorly understood. Here, we performed a comprehensive analysis of light-inducible genes in the chicken pineal gland, which consists of light-sensitive clock cells representing a prototype of the clock system. Light stimulated expression of 62 genes and 40 ESTs by >2.5-fold, among which genes responsive to the heat shock and endoplasmic reticulum stress as well as their regulatory transcription factors heat shock factor (HSF)1, HSF2, and X-box-binding protein 1 (XBP1) were strongly activated when a light pulse was given at late subjective night. In contrast, the light pulse at early subjective night caused prominent induction of E4bp4, a key regulator in the phase-delaying mechanism of the pineal clock, along with activation of a large group of cholesterol biosynthetic genes that are targets of sterol regulatory element-binding protein (SREBP) transcription factor. We found that the light pulse stimulated proteolytic formation of active SREBP-1 that, in turn, transactivated E4bp4 expression, linking SREBP with the light-input pathway of the pineal clock. As an output of light activation of cholesterol biosynthetic genes, we found light-stimulated pineal production of a neurosteroid, 7α-hydroxypregnenolone, demonstrating a unique endocrine function of the pineal gland. Intracerebroventricular injection of 7α-hydroxypregnenolone activated locomotor activities of chicks. Our study on the genome-wide gene expression analysis revealed time-of-day-dependent light activation of signaling pathways and provided molecular connection between gene expression and behavior through neurosteroid release from the pineal gland.


Assuntos
Ritmo Circadiano/fisiologia , Proteínas de Ligação a DNA/metabolismo , Regulação da Expressão Gênica/fisiologia , Proteínas de Choque Térmico/metabolismo , Luz , Transdução de Sinais/fisiologia , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo , Fatores de Transcrição/metabolismo , 17-alfa-Hidroxipregnenolona/análogos & derivados , 17-alfa-Hidroxipregnenolona/farmacologia , Animais , Sequência de Bases , Comportamento Animal/efeitos dos fármacos , Comportamento Animal/fisiologia , Comportamento Animal/efeitos da radiação , Galinhas , Colesterol/biossíntese , Ritmo Circadiano/efeitos dos fármacos , Ritmo Circadiano/efeitos da radiação , Retículo Endoplasmático/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos da radiação , Estudo de Associação Genômica Ampla , Locomoção/efeitos dos fármacos , Locomoção/fisiologia , Locomoção/efeitos da radiação , Masculino , Dados de Sequência Molecular , Fatores de Transcrição de Fator Regulador X , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/efeitos da radiação
6.
Horm Behav ; 62(4): 375-80, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22796546

RESUMO

Reproductive behavior in amphibians, as in other vertebrate animals, is controlled by multiple hormones. A neurosteroid, 7α-hydroxypregnenolone, has recently been found to enhance locomotor activity in the male newt, Cynops pyrrhogaster. Here, we show that this neurosteroid is also involved in enhancing the expression of courtship behavior. Intracerebroventricular (ICV) injection of 7α-hydroxypregnenolone enhanced courtship behavior dose-dependently in the sexually undeveloped males that had been pretreated with prolactin and gonadotropin, which is known to bring the males to a sexually developed state. But, unlike the case in the locomotion activity, 7α-hydroxypregnenolone did not elicit the behavior in males receiving no prior injections of these hormones. ICV administration of ketoconazole, an inhibitor of the steroidogenic enzyme cytochrome P450s, suppressed the spontaneously occurring courtship behavior in sexually active males. Supplementation with 7α-hydroxypregnenolone reversed the effect of ketoconazole in these animals. It was also demonstrated that the effect of the neurosteroid on the courtship behavior was blocked by a dopamine D2-like, but not by a D1-like, receptor antagonist. These results indicate that endogenous 7α-hydroxypregnenolone enhances the expression of the male courtship behavior through a dopaminergic system mediated by a D2-like receptor in the brain.


Assuntos
17-alfa-Hidroxipregnenolona/análogos & derivados , Corte , Salamandridae/fisiologia , Comportamento Sexual Animal/efeitos dos fármacos , Inibidores de 14-alfa Desmetilase/farmacologia , 17-alfa-Hidroxipregnenolona/farmacologia , Animais , Benzazepinas/farmacologia , Antagonistas de Dopamina/farmacologia , Neurônios Dopaminérgicos/efeitos dos fármacos , Neurônios Dopaminérgicos/fisiologia , Relação Dose-Resposta a Droga , Feminino , Cetoconazol/farmacologia , Masculino , Neurotransmissores/farmacologia , Neurotransmissores/fisiologia
7.
Gen Comp Endocrinol ; 176(3): 440-7, 2012 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-22138220

RESUMO

Seasonally-breeding amphibians have served as excellent animal models to investigate the biosynthesis and biological actions of neurosteroids. Previous studies have demonstrated that the brain of amphibians possesses key steroidogenic enzymes and produces pregnenolone, a precursor of steroid hormones, and other various neurosteroids. We recently found that the brain of seasonally-breeding newts actively produces 7α-hydroxypregnenolone, a previously undescribed amphibian neurosteroid. This novel amphibian neurosteroid acts as a neuronal modulator to stimulate locomotor activity in newts. Subsequently, the mode of action of 7α-hydroxypregnenolone has been demonstrated in the newt brain. 7α-Hydroxypregnenolone stimulates locomotor activity through activation of the dopaminergic system. To understand the functional significance of 7α-hydroxypregnenolone in the regulation of locomotor activity, diurnal and seasonal changes in synthesis of 7α-hydroxypregnenolone have also been demonstrated in the newt brain. Melatonin derived from the pineal gland and eyes regulates 7α-hydroxypregnenolone synthesis in the brain, thus inducing diurnal locomotor changes. Prolactin, an adenohypophyseal hormone, regulates 7α-hydroxypregnenolone synthesis in the brain, and also induces seasonal locomotor changes. In addition, 7α-hydroxypregnenolone mediates corticosterone action to increase locomotor activity under stress. This review summarizes the discovery, progress and prospect of 7α-hydroxypregnenolone, a new key regulator of amphibian locomotion.


Assuntos
17-alfa-Hidroxipregnenolona/análogos & derivados , Encéfalo/fisiologia , Locomoção/fisiologia , Salamandridae/fisiologia , 17-alfa-Hidroxipregnenolona/metabolismo , Animais , Ritmo Circadiano/fisiologia , Dopamina/fisiologia , Melatonina/fisiologia , Estações do Ano
8.
Endocr J ; 58(7): 527-34, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21521927

RESUMO

Adrenocortical carcinoma (ACC) is a very rare malignant tumor with poor prognosis. To gain insight into the pathogenic significance of ACC, we studied clinicopathological features and gene expression profile in ACC. We analyzed five ACC cases (two men and three women) with the median age of 45-year-old who underwent adrenalectomy at our institute. Endocrine studies revealed that two cases had subclinical Cushing's syndrome (SCS) and one with concomitant estrogen-secreting tumor, while the rest of three cases had non-functioning tumors. Analysis of urinary steroids profile by gas chromatography/mass spectrometry showed increased metabolites of corticosteroid precursors, such as 17-OH pregnenolone, 17-OH progesterone, dehydroepiandorosterone (DHEA), and 11-deoxycortisol in all five cases. The pathological diagnosis of ACC was based on Weiss's criteria with its score ≥ 3. The mean size of the resected tumors was 87 mm and Ki67/MIB1 labeling index, a proliferative marker, was 3-27%. Immunohistochemical analysis revealed a disorganized expression of several steroidogenic enzymes, such as 3ß-hydroxysteroid dehydrogenase, 17α-hydroxylase, and DHEA-sulfotransferase. Among several genes determined by RT-PCR, insulin-like growth factor (IGF)-II mRNA was consistently and abundantly expressed in all 5 tumor tissues. Postoperatively, two cases with SCS developed local recurrence and liver metastasis. The present study suggests that the disorganized expression of steroidogenic enzymes and the overexpression of IGF-II by the tumor are hallmarks of ACC, which could be used as biochemical and molecular markers for ACC.


Assuntos
17-alfa-Hidroxipregnenolona/análogos & derivados , 17-alfa-Hidroxiprogesterona/metabolismo , Neoplasias do Córtex Suprarrenal/patologia , Carcinoma Adrenocortical/patologia , Cortodoxona/metabolismo , Desidroepiandrosterona/metabolismo , 17-alfa-Hidroxipregnenolona/metabolismo , 17-alfa-Hidroxipregnenolona/urina , 17-alfa-Hidroxiprogesterona/urina , Neoplasias do Córtex Suprarrenal/metabolismo , Neoplasias do Córtex Suprarrenal/cirurgia , Neoplasias do Córtex Suprarrenal/urina , Carcinoma Adrenocortical/metabolismo , Carcinoma Adrenocortical/cirurgia , Carcinoma Adrenocortical/urina , Adulto , Cortodoxona/urina , Desidroepiandrosterona/urina , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Perfilação da Expressão Gênica , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , RNA Neoplásico/química , RNA Neoplásico/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa
9.
Gen Comp Endocrinol ; 168(2): 275-9, 2010 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-20138182

RESUMO

We now know that steroids can be synthesized de novo by the brain and the peripheral nervous system. Such steroids are called neurosteroids and de novo neurosteroidogenesis from cholesterol is a conserved property of vertebrate brains. Our studies over the past decade have demonstrated that the brain expresses several kinds of steroidogenic enzymes and produces a variety of neurosteroids in sub-mammalian species. However, neurosteroid biosynthetic pathways in amphibians, as well as other vertebrates may still not be fully mapped. We first found that the newt brain actively produces 7alpha-hydroxypregnenolone, a previously undescribed amphibian neurosteroid. We then demonstrated that 7alpha-hydroxypregnenolone acts as a novel bioactive neurosteroid to stimulate locomotor activity of newt by means of the dopaminergic system. Subsequently, we analyzed the physiological roles of 7alpha-hydroxypregnenolone in the regulation of locomotor activity of newt. This paper summarizes the advances made in our understanding of 7alpha-hydroxypregnenolone, a newly discovered bioactive amphibian neurosteroid stimulating locomotor activity, and its physiological roles in the regulation of locomotion in newt.


Assuntos
17-alfa-Hidroxipregnenolona/análogos & derivados , Anfíbios/metabolismo , Atividade Motora/fisiologia , Neurotransmissores/metabolismo , 17-alfa-Hidroxipregnenolona/metabolismo , Animais , Encéfalo/metabolismo , Encéfalo/fisiologia , Ritmo Circadiano/fisiologia , Salamandridae , Estações do Ano
10.
J Neurosci ; 28(9): 2158-67, 2008 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-18305249

RESUMO

Melatonin regulates diurnal changes in locomotor activity in vertebrates, but the molecular mechanism for this neurohormonal regulation of behavior is poorly understood. Here we show that 7alpha-hydroxypregnenolone, a previously undescribed avian neurosteroid, mediates melatonin action on diurnal locomotor rhythms in quail. In this study, we first identified 7alpha-hydroxypregnenolone and its stereoisomer 7beta-hydroxypregnenolone in quail brain. These neurosteroids have not been described previously in avian brain. We then demonstrated that 7alpha-hydroxypregnenolone acutely increased quail locomotor activity. To analyze the production of 7alpha-hydroxypregnenolone, cytochrome P450(7alpha), a steroidogenic enzyme of this neurosteroid, was also identified. Subsequently, we demonstrated diurnal changes in 7alpha-hydroxypregnenolone synthesis in quail. 7Alpha-Hydroxypregnenolone synthesis and locomotor activity in males were much higher than in females. This is the first demonstration in any vertebrate of a clear sex difference in neurosteroid synthesis. This sex difference in 7alpha-hydroxypregnenolone synthesis corresponded to the sex difference in locomotion. We show that only males exhibited marked diurnal changes in 7alpha-hydroxypregnenolone synthesis, and these changes occurred in parallel with changes in locomotor activity. Finally, we identified melatonin as a key component of the mechanism regulating 7alpha-hydroxypregnenolone synthesis. Increased synthesis of 7alpha-hydroxypregnenolone occurred in males in vivo after melatonin removal via pinealectomy and orbital enucleation (Px plus Ex). Conversely, decreased synthesis of this neurosteroid occurred after melatonin administration to Px plus Ex males. This study demonstrates that melatonin regulates synthesis of 7alpha-hydroxypregnenolone, a key factor for induction of locomotor activity, thus inducing diurnal locomotor changes in male birds. This is a previously undescribed role for melatonin.


Assuntos
17-alfa-Hidroxipregnenolona/análogos & derivados , Encéfalo/metabolismo , Ritmo Circadiano/fisiologia , Melatonina/administração & dosagem , Atividade Motora/fisiologia , 17-alfa-Hidroxipregnenolona/classificação , 17-alfa-Hidroxipregnenolona/metabolismo , Animais , Comportamento Animal/efeitos dos fármacos , Química Encefálica/fisiologia , Células COS , Chlorocebus aethiops , Cromatografia Líquida de Alta Pressão , Clonagem Molecular/métodos , Enucleação Ocular/métodos , Feminino , Masculino , Melatonina/antagonistas & inibidores , Melatonina/metabolismo , Atividade Motora/efeitos dos fármacos , Glândula Pineal/lesões , Glândula Pineal/fisiologia , Codorniz , Transfecção , Triptaminas/farmacologia
11.
Gen Comp Endocrinol ; 163(1-2): 117-22, 2009 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-19362555

RESUMO

The discovery of two novel avian neurosteroids in the quail brain, 7alpha- and 7beta-hydroxypregnenolone is described. Intracerebroventricular administration of 7alpha-hydroxypregnenolone, but not 7beta-hydroxypregnenolone was found to stimulate locomotor activity of male quail when spontaneous nocturnal activity is low. Diurnal changes in locomotor activity in male quail were found to be correlated with a diurnal change in the concentration of diencephalic 7alpha-hydroxypregnenolone. This correlation was a not seen in female quail which have a lower amplitude diurnal rhythm of locomotor activity and lower daytime concentrations of diencephalic 7alpha-hydroxypregnenolone. Treatment of male quail with melatonin was found to depress the synthesis of 7alpha-hydroxypregnenolone in the diencephalon. This is a previously undescribed role for melatonin in the regulation of neurosteroid synthesis in the brain of any vertebrate. We therefore deduced in male quail, that the nocturnal depression in locomotory activity is a consequence of a depression in diencephalic 7alpha-hydroxypregnenolone resulting from the inhibitory action of the nocturnal increase in melatonin. This observation may be of widespread significance for the molecular control of rhythmic locomotor activity in all vertebrates.


Assuntos
17-alfa-Hidroxipregnenolona/análogos & derivados , Ritmo Circadiano/fisiologia , Coturnix/fisiologia , Atividade Motora/fisiologia , 17-alfa-Hidroxipregnenolona/metabolismo , Animais , Coturnix/metabolismo , Diencéfalo/efeitos dos fármacos , Diencéfalo/metabolismo , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Masculino , Melatonina/metabolismo , Melatonina/farmacologia
12.
J Neurosci ; 26(43): 11034-40, 2006 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-17065445

RESUMO

Pregnenolone (PREG) and dehydroepiandrosterone (DHEA) have been reported to improve memory in aged rodents. In brain, these neurosteroids are transformed predominantly into 7alpha-hydroxylated metabolites by the cytochrome P450-7B1 (CYP7B). The biological role of steroid B-ring hydroxylation is unclear. It has been proposed to generate bioactive derivatives that enhance cognition, immune, and other physiological processes. In support, 7alpha-hydroxylated DHEA increases the immune response in mice with greater potency than the parent steroid. Whether the memory-enhancing effects of PREG in rats is mediated via its 7alpha-hydroxylated metabolite 7alpha-hydroxyPREG is not known. We investigated this by treating memory-impaired aged rats (identified by their spatial memory performances in the Morris water maze task compared with young controls) with 7alpha-hydroxyPREG or PREG administered intracerebroventricularly using osmotic minipumps and then tested the rats during week 2 of steroid treatment in the eight-arm radial-arm version of the water maze (RAWM) that allows repeated assessment of learning. CYP7B bioactivity in hippocampal tissue (percentage conversion of [14C]DHEA to [14C]7alpha-hydroxyDHEA) was decreased selectively in memory-impaired aged rats compared with both young and memory-intact aged rats. 7alpha-hydroxyPREG (100 ng/h) but not PREG (100 ng/h) administration to memory-impaired aged rats for 11 d enhanced spatial memory retention (after a 30 min delay between an exposure trial 1 and test trial 2) in the RAWM. These data provide evidence for a biologically active enzyme product 7alpha-hydroxyPREG and suggests that reduced CYP7B function in the hippocampus of memory-impaired aged rats may, in part, be overcome by administration of 7alpha-hydroxyPREG.


Assuntos
17-alfa-Hidroxipregnenolona/análogos & derivados , Envelhecimento/efeitos dos fármacos , Sistema Enzimático do Citocromo P-450/administração & dosagem , Retenção Psicológica/efeitos dos fármacos , Comportamento Espacial/efeitos dos fármacos , Esteroide Hidroxilases/administração & dosagem , 17-alfa-Hidroxipregnenolona/administração & dosagem , Envelhecimento/fisiologia , Animais , Família 7 do Citocromo P450 , Injeções Intraventriculares , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Aprendizagem em Labirinto/fisiologia , Memória/efeitos dos fármacos , Memória/fisiologia , Ratos , Retenção Psicológica/fisiologia , Comportamento Espacial/fisiologia
13.
Steroids ; 72(4): 323-7, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17298837

RESUMO

New combined radioimmunoassay for determination of 17-hydroxypregnenolone sulfate (17-PregS) involving the hydrolysis of analyte by methanolysis was developed. 17-PregS, in addition to being secreted by the adrenals, is also formed by peripheral sulfoconjugation of 17-hydroxypregnenolone (17-Preg) or directly by hydroxylation of pregnenolone sulfate with 17alpha-hydroxylase/C17-20lyase. The measurement of 17-PregS can be used as a tool for detection of enzymatic deficiency particularly in pregnancy and for detection of congenital adrenal hyperplasia or gonadal dysfunction. The serum levels of 17-PregS, 17-Preg, dehydroepiandrosterone, dehydroepiandrosterone sulfate, pregnenolone and pregnenolone sulfate were measured in different age groups of human and in pregnant women respecting the age of gestation. The levels of 17-PregS are approximately three times higher than the levels of free 17-Preg in all subject groups. The levels of 17-PregS during pregnancy reached the local minimum in the 3rd month of gestation. The ratio of 17-PregS to free 17-Preg showed increasing profile during pregnancy with a maximum in the 8th month of gestation. These findings indicate that, the conversion of pregnenolone sulfate to 17-PregS is the major metabolic pathway for biosynthesis of 17-PregS.


Assuntos
17-alfa-Hidroxipregnenolona/análogos & derivados , Radioimunoensaio/métodos , 17-alfa-Hidroxipregnenolona/sangue , 17-alfa-Hidroxipregnenolona/metabolismo , Adolescente , Adulto , Fatores Etários , Criança , Pré-Escolar , Feminino , Idade Gestacional , Humanos , Masculino , Ciclo Menstrual , Pessoa de Meia-Idade , Gravidez , Valores de Referência , Fatores Sexuais
14.
Steroids ; 128: 50-57, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-29061488

RESUMO

7α-Hydroxypregnenolone is an endogenous neuroactive steroid that stimulates locomotor activity. A synthesis of 7α-hydroxypregnenolone from pregnenolone, which takes advantage of an orthogonal protecting group strategy, is described. In detail, the C7-position was oxidized with CrO3 and 3,5-dimethylpyrazole to yield a 7-keto steroid intermediate. The resulting 7-ketone was stereoselectively reduced to the 7α-hydroxy group with lithium tri-sec-butylborohydride. In contrast, reduction of the same 7-ketone intermediate with NaBH4 resulted in primarily the 7ß-hydroxy epimer. Furthermore, in an alternative route to the target compound, the 7α-hydroxy group was successfully incorporated by direct C-H allylic benzoyloxylation of pregnenolone-3-acetate with CuBr and tert-butyl peroxybenzoate followed by saponification. The disclosed syntheses to 7-oxygenated steroids are amenable to potentially obtain other biologically active sterols and steroids.


Assuntos
17-alfa-Hidroxipregnenolona/análogos & derivados , Locomoção/efeitos dos fármacos , Esteroides/síntese química , 17-alfa-Hidroxipregnenolona/síntese química , 17-alfa-Hidroxipregnenolona/uso terapêutico , Benzoatos/química , Encéfalo/efeitos dos fármacos , Encéfalo/fisiologia , Humanos , Melatonina/metabolismo , Esteroides/uso terapêutico
15.
J Clin Endocrinol Metab ; 102(8): 2701-2710, 2017 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-28472487

RESUMO

Context: Patients with 21-hydroxylase deficiency (21OHD) have long-term complications, resulting from poor disease control and/or glucocorticoid overtreatment. Lack of optimal biomarkers has made it challenging to tailor therapy and predict long-term outcomes. Objective: To identify biomarkers of disease control and long-term complications in 21OHD. Setting and Participants: Cross-sectional study of 114 patients (70 males), ages 2 to 67 years (median, 15 years), seen in a tertiary referral center. Methods: We correlated a mass-spectrometry panel of 23 steroids, obtained before first morning medication, with bone age advancement (children), adrenal volume (adults), testicular adrenal rest tumors (TART), hirsutism, menstrual disorders, and pituitary hormones. Results: Total adrenal volume correlated positively with 18 steroids, most prominently 21-deoxycortisol and four 11-oxygenated-C19 (11oxC19) steroids: 11ß-hydroxyandrostenedione (11OHA4), 11-ketoandrostenedione (11ketoA4), 11ß-hydroxytestosterone (11OHT), and 11-ketotestosterone (11ketoT) (r ≈ 0.7, P < 0.0001). Nine steroids were significantly higher (P ≤ 0.01) in males with TART compared with those without TART, including 11OHA4 (6.8-fold), 11OHT (4.9-fold), 11ketoT (3.6-fold), 11ketoA4 (3.3-fold), and pregnenolone sulfate (PregS; 4.8-fold). PregS (28.5-fold) and 17-hydroxypregnenolone sulfate (19-fold) levels were higher (P < 0.01) in postpubertal females with menstrual disorders. In males, testosterone levels correlated positively with all 11oxC19 steroids in Tanner stages 1 and 2 (r ≈ 0.7; P < 0.001) but negatively in Tanner stage 5 (r = -0.3 and P < 0.05 for 11ketoA4 and 11ketoT). In females, testosterone level correlated positively with all four 11oxC19 steroids across all Tanner stages (r ≈ 0.8; P < 0.0001). Conclusion: 11oxC19 steroids and PregS might serve as clinically useful biomarkers of disease control and long-term complications in 21OHD.


Assuntos
Hiperplasia Suprarrenal Congênita/metabolismo , Tumor de Resto Suprarrenal/metabolismo , Androgênios/metabolismo , Hirsutismo/metabolismo , Distúrbios Menstruais/metabolismo , Neoplasias Testiculares/metabolismo , 17-alfa-Hidroxipregnenolona/análogos & derivados , 17-alfa-Hidroxipregnenolona/metabolismo , Adolescente , Glândulas Suprarrenais/patologia , Adulto , Determinação da Idade pelo Esqueleto , Idoso , Androstenodiona/análogos & derivados , Androstenodiona/metabolismo , Androstenos/metabolismo , Criança , Pré-Escolar , Cortodoxona/metabolismo , Estudos Transversais , Feminino , Humanos , Hidroxitestosteronas/metabolismo , Masculino , Pessoa de Meia-Idade , Tamanho do Órgão , Pregnenolona/metabolismo , Testosterona/análogos & derivados , Testosterona/metabolismo , Adulto Jovem
16.
Steroids ; 111: 54-59, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-26844377

RESUMO

Steroids have been widely used in the clinical setting. They bind and activate nuclear receptors to regulate gene expression. In addition to activating genomic transcription, steroids also exert nongenomic actions. The current article focuses on the nongenomic actions of neurosteroids, including pregnenolone (P5), 7α-hydroxypregnenolone, pregnenolone sulfate and allopregnanolone. Pregnenolone and its derivatives promote neuronal activity by enhancing learning and memory, relieving depression, enhancing locomotor activity, and promoting neuronal cell survival. They exert these effects by activating various target proteins located in the cytoplasm or cell membrane. Pregnenolone and its metabolites bind to receptors such as microtubule-associated proteins and neurotransmitter receptors to elicit a series of reactions including stabilization of microtubules, increase of ion flux into cells, and dopamine release. The wide actions of neurosteroids indicate that pregnenolone derivatives have great potential in future treatment of neurological diseases.


Assuntos
Neurotransmissores/uso terapêutico , Pregnenolona/uso terapêutico , 17-alfa-Hidroxipregnenolona/análogos & derivados , 17-alfa-Hidroxipregnenolona/farmacologia , 17-alfa-Hidroxipregnenolona/uso terapêutico , Animais , Depressão/tratamento farmacológico , Depressão/metabolismo , Humanos , Microtúbulos/efeitos dos fármacos , Microtúbulos/metabolismo , Doenças Neurodegenerativas/tratamento farmacológico , Doenças Neurodegenerativas/metabolismo , Neurotransmissores/farmacologia , Pregnanolona/farmacologia , Pregnanolona/uso terapêutico , Pregnenolona/farmacologia
17.
Sci Rep ; 5: 12546, 2015 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-26220247

RESUMO

Salmon migrate upstream against an opposing current in their natal river. However, the molecular mechanisms that stimulate upstream migratory behavior are poorly understood. Here, we show that 7α-hydroxypregnenolone (7α-OH PREG), a newly identified neuronal modulator of locomotion, acts as a key factor for upstream migration in salmon. We first identified 7α-OH PREG and cytochrome P450 7α-hydroxylase (P4507α), a steroidogenic enzyme producing 7α-OH PREG, in the salmon brain and then found that 7α-OH PREG synthesis in the brain increases during upstream migration. Subsequently, we demonstrated that 7α-OH PREG increases upstream migratory behavior of salmon. We further found that 7α-OH PREG acts on dopamine neurons in the magnocellular preoptic nucleus during upstream migration. Thus, 7α-OH PREG stimulates upstream migratory behavior through the dopaminergic system in salmon. These findings provide new insights into the molecular mechanisms of fish upstream migration.


Assuntos
17-alfa-Hidroxipregnenolona/análogos & derivados , Comportamento Animal/efeitos dos fármacos , Dopamina/metabolismo , Neurônios Dopaminérgicos/efeitos dos fármacos , Locomoção/efeitos dos fármacos , Atividade Motora/efeitos dos fármacos , Salmão/fisiologia , 17-alfa-Hidroxipregnenolona/farmacologia , Animais , Comportamento Animal/fisiologia , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Encéfalo/fisiologia , Estimulantes do Sistema Nervoso Central/farmacologia , Neurônios Dopaminérgicos/metabolismo , Neurônios Dopaminérgicos/fisiologia , Feminino , Locomoção/fisiologia , Masculino , Dados de Sequência Molecular , Atividade Motora/fisiologia
18.
J Invest Dermatol ; 81(1): 70-4, 1983 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-6223099

RESUMO

We have studied a group of young adult women of mean age 23.8 +/- 6.5 (SD) years with only acne (A, n = 46), only hirsutism (H, n = 10), and acne plus hirsutism (A + H, n = 19) who sought dermatologic care. We measured the androgens, total and free testosterone (T), free 17 beta-hydroxysteroids (17-beta), dehydroepiandrosterone sulfate (DS), and the androgen precursors 17 alpha-hydroxypregnenolone (17-Preg) and 17 alpha-hydroxyprogesterone (17-Prog), as well as testosterone-estrogen binding globulin in all patients. Plasma hormone levels of the patients were compared to those of 23 controls of mean age 25.6 +/- 6.6 years who had neither acne nor hirsutism. Mean levels of all hormones measured, except 17-Preg, were elevated in the women with acne. Fifty-two percent of Group A, 60% of Group H, and 63% of Group A + H patients had at least one abnormal hormone level. The most frequently elevated plasma androgens in all the women with acne were: free T 25%, free 17-beta 23%, and DS 19%. Total T was high in only 12%. Elevations of plasma androgens were present in some women who did not have hirsutism or irregular menses. Identification of endocrine abnormalities in women with acne may potentially offer an opportunity for hormonal therapy.


Assuntos
Acne Vulgar/sangue , Androgênios/sangue , 17-alfa-Hidroxipregnenolona/análogos & derivados , 17-alfa-Hidroxipregnenolona/sangue , 17-alfa-Hidroxiprogesterona , Adolescente , Adulto , Desidroepiandrosterona/sangue , Feminino , Hirsutismo/sangue , Humanos , Hidroxiprogesteronas/sangue , Hidroxiesteroides/sangue , Distúrbios Menstruais/sangue , Globulina de Ligação a Hormônio Sexual/análise , Testosterona/sangue
19.
J Endocrinol ; 67(1): 89-97, 1975 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-1194830

RESUMO

Using specific radioimmunoassays, 17alpha,20alpha-dihydroxypregn-4-en-3-one and progesterone were measured in maternal utero-ovarian venous plasma from four sheep during parturition induced with dexamethasone and two sheep at spontaneous delivery. 17alpha,20alpha-Dihydroxypregn-4-en-3-one was also measured in maternal jugular venous and foetal posterior vena caval plasma from one dexamethasone-induced animal over the same period. Basal utero-ovarian venous levels of 17alpha,20alpha-dihydroxypregn-4-en-3-one were in the range 3-7 ng/ml; at the time of the pre-labour fall in maternal progesterone, the concentration of 17alpha-20alpha-dihydroxypregn-4-en-3-one increased, reaching 17-76 ng/ml at delivery. Maternal levels fell rapidly after delivery. In contrast to foetal progesterone concentrations, which are low, foetal 17alpha,20alpha-dihydroxypregn-4-en-3-one levels were approximately the same as those in the maternal utero-ovarian vein. Maternal jugular venous levels in one animal were 50-80% of those in the utero-ovarian vein. These findings confirm earlier results obtained in vitro which indicated that exposure to glucocorticoid results in increased activity of a steroid 17alpha-hydroxylase in the ovine foetal placenta.


Assuntos
17-alfa-Hidroxipregnenolona/análogos & derivados , Trabalho de Parto , 17-alfa-Hidroxipregnenolona/sangue , Animais , Dexametasona/farmacologia , Feminino , Sangue Fetal/análise , Trabalho de Parto Induzido , Gravidez , Progesterona/sangue , Radioimunoensaio , Ovinos , Fatores de Tempo
20.
J Endocrinol ; 69(3): 433-44, 1976 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-950536

RESUMO

Progesterone, 17 alpha, 20 alpha-dihydroxypregn-4-en-3-one, androstenedione, total unconjugated oestrogen and oestrone sulphate have been measured by radioimmunoassays in maternal utero-ovarian venous, maternal peripheral venous and/or foetal posterior vena caval plasma from six sheep bearing bilaterally adrenalectomized lambs, in which premature parturition was induced by administration of glucocorticoid. Three of the ewes were overiectomized, and in one of these three animals the foetal testes were also excised, at the time of foetal adrenalectomy. Adrenalectomy was judged to be complete on the basis of plasma cortisol levels in the neonatal lambs, and by examination of the site of ablation at necropsy. In all cases foetal administration of glucocorticoid led to the onset of labour, and lambing, and in all animals the hormonal changes preceding parturition were indistinguishable (either qualitatively or quantitatively) from the changes observed in animals carrying intact lambs. Since therapy with glucocorticoid alone successfully compensates for ablation of the foetal adrenal cortex, it is suggested that glucocorticoid is the only adrenal product required to cause parturition, and that foetal adrenal secretion of androgens may be unnecessary.


Assuntos
Glândulas Suprarrenais/embriologia , Ovinos/fisiologia , 17-alfa-Hidroxipregnenolona/análogos & derivados , 17-alfa-Hidroxipregnenolona/sangue , Adrenalectomia , Androstenodiona , Animais , Dexametasona/farmacologia , Estrogênios/sangue , Estrona/sangue , Feminino , Hidrocortisona/sangue , Gravidez , Progesterona/sangue , Fatores de Tempo
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