RESUMO
OBJECTIVE: To investigate the influence of substance P on gonadotropin release from the pituitary as evaluated according to the final effect, i.e. the ovulation. METHODS: Stainless steel tube was implanted into the 3rd cerebral ventricle and substance P (SP), C-terminal hexapeptide of Substance P (SP6-11), Gn-RH and adrenaline were infused on the 3rd day of the cycle (proestrus). The oviducts were then isolated on the day of estrus and the ova were counted. RESULTS: SP or SP6-11 inhibited the ovulation which was not prevented by intracerebroventricular (i.c.v.) capsaicin pretreatment. The i.c. v. administration of noradrenaline on the 7-8th day of pseudopregnancy induced the ovulation which was prevented by the injection of SP immediately before noradrenaline. CONCLUSIONS: It is suggested that noradrenergic neuros which control the ovulation by influencing the release of Gn-RH into pituitary portal vessels are affected by SP-ergic neurons.
Assuntos
Homeostase , Ovulação/fisiologia , Substância P/fisiologia , Animais , Capsaicina/farmacologia , Ventrículos Cerebrais/efeitos dos fármacos , Encefalina Metionina/farmacologia , Epinefrina/administração & dosagem , Epinefrina/farmacologia , Feminino , Hormônio Liberador de Gonadotropina/administração & dosagem , Hormônio Liberador de Gonadotropina/farmacologia , Ovulação/efeitos dos fármacos , Fragmentos de Peptídeos/administração & dosagem , Fragmentos de Peptídeos/farmacologia , Pseudogravidez , Ácido Pirrolidonocarboxílico/análogos & derivados , Ratos , Ratos Endogâmicos BUF , Ratos Wistar , Substância P/administração & dosagem , Substância P/farmacologiaRESUMO
We have shown that the complexation of luteinizing hormone releasing hormone, luliberin (LHRH), a hypothalamic neurohormone, by Cu(II), Ni(II), and Zn(II) may affect its basic, ovulation-inducing potency in the dose responsive manner. Some explanation of the obtained results are offered here.
