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Ventura,R.R.; Gomes,D.A.; Reis,W.L.; Elias,L.L.K.; Castro,M.; Valença,M.M.; Carnio,E.C.; Rettori,V.; McCann,S.M.; Antunes-Rodrigues,J.. |
The central nervous system plays an important role in the control of renal sodium excretion. We present here a brief review of physiologic regulation of hydromineral balance and discuss recent results from our laboratory that focus on the participation of nitrergic, vasopressinergic, and oxytocinergic systems in the regulation of water and sodium excretion under different salt intake and hypertonic blood volume expansion (BVE) conditions. High sodium intake induced a significant increase in nitric oxide synthase (NOS) activity in the medial basal hypothalamus and neural lobe, while a low sodium diet decreased NOS activity in the neural lobe, suggesting that central NOS is involved in the control of sodium balance. An increase in plasma concentrations in... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Vasopressin; Oxytocin; ANP; Nitric oxide; Blood volume expansion; Sodium diet. |
Ano: 2002 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2002000900011 |
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Gutkowska,J.; Jankowski,M.; Mukaddam-Daher,S.; McCann,S.M.. |
Oxytocin (OT), a nonapeptide, was the first hormone to have its biological activities established and chemical structure determined. It was believed that OT is released from hypothalamic nerve terminals of the posterior hypophysis into the circulation where it stimulates uterine contractions during parturition, and milk ejection during lactation. However, equivalent concentrations of OT were found in the male hypophysis, and similar stimuli of OT release were determined for both sexes, suggesting other physiological functions. Indeed, recent studies indicate that OT is involved in cognition, tolerance, adaptation and complex sexual and maternal behaviour, as well as in the regulation of cardiovascular functions. It has long been known that OT induces... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Oxytocin; Natriuretic peptides; Heart. |
Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2000000600003 |
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Picanço-Diniz,D.L.W.; Valença,M.M.; Favaretto,A.L.V.; McCann,S.M.; Antunes-Rodrigues,J.. |
We investigated the participation of A1 or A2 receptors in the gonadotrope and their role in the regulation of LH and FSH secretion in adult rat hemipituitary preparations, using adenosine analogues. A dose-dependent inhibition of LH and FSH secretion was observed after the administration of graded doses of the R-isomer of phenylisopropyladenosine (R-PIA; 1 nM, 10 nM, 100 nM, 1 µM and 10 µM). The effect of R-PIA (10 nM) was blocked by the addition of 8-cyclopentyltheophylline (CPT), a selective A1 adenosine receptor antagonist, at the dose of 1 µM. The addition of an A2 receptor-specific agonist, 5-N-methylcarboxamidoadenosine (MECA), at the doses of 1 nM to 1 µM had no significant effect on LH or FSH secretion, suggesting the absence of this receptor... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Adenosine; LH; FSH; A1 receptor; Anterior pituitary. |
Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1999000900017 |
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McCann,S.M.; Mastronardi,C.; Walczewska,A.; Karanth,S.; Rettori,V.; Yu,W.H.. |
Nitric oxide (NO) plays a crucial role in reproduction at every level in the organism. In the brain, it activates the release of luteinizing hormone-releasing hormone (LHRH). The axons of the LHRH neurons project to the mating centers in the brain stem and by afferent pathways evoke the lordosis reflex in female rats. In males, there is activation of NOergic terminals that release NO in the corpora cavernosa penis to induce erection by generation of cyclic guanosine monophosphate (cGMP). NO also activates the release of LHRH which reaches the pituitary and activates the release of gonadotropins by activating neural NO synthase (nNOS) in the pituitary gland. In the gonad, NO plays an important role in inducing ovulation and in causing luteolysis, whereas in... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: NO and synthase; NG-monomethyl-L-arginine; Nitroprusside; NOergic neurons; FSH; LH; LHRH; FSHRF. |
Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1999001100007 |
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