Interaction between NO and oxytocin: Influence on LHRH release
Autor: | V. Rettori, G. Canteros, S.M. McCann |
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Jazyk: | angličtina |
Rok vydání: | 1997 |
Předmět: | |
Zdroj: | Brazilian Journal of Medical and Biological Research, Vol 30, Iss 4, p 453 (1997) |
Druh dokumentu: | article |
ISSN: | 0100-879X 1414-431X |
DOI: | 10.1590/S0100-879X1997000400004 |
Popis: | Nitric oxide synthase (NOS)-containing neurons have been localized in various parts of the CNS. These neurons occur in the hypothalamus, mostly in the paraventricular and supraoptic nuclei and their axons project to the neural lobe of the pituitary gland. We have found that nitric oxide (NO) controls luteinizing hormone-releasing hormone (LHRH) release from the hypothalamus acting as a signal transducer in norepinephrine (NE)-induced LHRH release. LHRH not only releases LH from the pituitary but also induces sexual behavior. On the other hand, it is known that oxytocin also stimulates mating behavior and there is some evidence that oxytocin can increase NE release. Therefore, it occurred to us that oxytocin may also stimulate LHRH release via NE and NO. To test this hypothesis, we incubated medial basal hypothalamic (MBH) explants from adult male rats in vitro. Following a preincubation period of 30 min, MBH fragments were incubated in Krebs-Ringer bicarbonate buffer in the presence of various concentrations of oxytocin. Oxytocin released LHRH at concentrations ranging from 0.1 nM to 1 µM with a maximal stimulatory effect (Pa1-adrenergic receptor antagonist, indicating that NE mediated this effect. Oxytocin at the same concentrations also increased the activity of NOS (P |
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