Substance P affects the GABAergic system in the hypothalamo-pituitary axis.
In the present work we examined the effect of the neutralization of endogenous substance P by the administration of an anti-substance P serum (ASPS) on GABA concentration in the anterior pituitary in hyperprolactinemic conditions induced by 5-hydroxytryptophan or by grafting anterior pituitaries. ASPS reduced the increase in the anterior pituitary GABA concentration induced by hyperprolactinemia. In vitro experiments showed that substance P inhibited K(+)-evoked GABA efflux from hypothalamic fragments and decreased GABA concentration in the anterior pituitary but ASPS increased it. Our results demonstrate that substance P modifies hypothalamic GABA release and anterior pituitary GABA concentration and suggest that an interaction exists between substance P and GABA.
Afione
S
S
Centro de Investigaciones en Reproducción, Facultad de Medicina Universidad de Buenos Aires, Argentina.
Debeljuk
L
L
Seilicovich
A
A
Pisera
D
D
Lasaga
M
M
Díaz
M C
MC
Duvilanski
B
B
D000818:Animals; D007030:Hypothalamo-Hypophyseal System / Q000502:physiology*; D007031:Hypothalamus / Q000378:metabolism; D066298:In Vitro Techniques; D010903:Pituitary Gland, Anterior / Q000378:metabolism / Q000502:physiology; D011388:Prolactin / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000502:physiology; D013373:Substance P / Q000276:immunology / Q000502:physiology*; D005680:gamma-Aminobutyric Acid / Q000502:physiology*
D012701:Serotonin; D013373:Substance P; D005680:gamma-Aminobutyric Acid; D011388:Prolactin