We studied the effects of histamine (HA) antagonists on the facilitatory action of morphine (M) and beta-endorphin (beta E) on prolactin (PRL) release and the effect of alpha-fluoromethylhistidine (alpha-FMH, inhibitor of HA synthesis) on beta E-induced PRL secretion. Male rats were injected intracerebroventricularly (i.c.v.) with mepyramine (MEP, H1-antagonist, 0.8 mumol/rat) or ranitidine (RAN, H2-antagonist, 0.4 mumol/rat) 10 min before M (6 mg/kg, intracarotid, i.a.) or beta E (0.25 micrograms/rat, i.c.v.). alpha-FMH (200 micrograms/rat, i.c.v.) was administered 3 h before beta E. Plasma PRL levels were measured at various times before and after drug treatment. RAN but not MEP significantly reduced PRL release induced by M whereas neither HA-antagonists nor alpha-FMH modified beta E-induced PRL release. The results obtained show that brain HA contributes through activation of H2-receptors to the PRL facilitatory action of M but not of beta E.
|Titolo:||A selective role for brain histamine in prolactin release induced by opiates|
GUIDOBONO CAVALCHINI, FRANCESCA (Secondo)
|Parole Chiave:||Rats, Inbred Strains; Rats; Prolactin; Methylhistidines; Animals; Ranitidine; Brain Chemistry; Pyrilamine; beta-Endorphin; Male; Injections, Intraventricular; Histamine|
|Settore Scientifico Disciplinare:||Settore BIO/14 - Farmacologia|
|Data di pubblicazione:||1990|
|Digital Object Identifier (DOI):||10.1007/BF01969044|
|Appare nelle tipologie:||01 - Articolo su periodico|