Prolactin release induced by opiate agonists, effect of glucocorticoid pretreatment in intact and adrenalectomized rats.
Cortisol administered at a dose of 25 mg/kg 24 h before measurements decreased the prolactin secretion induced by intraventricularly given opioids (dynorphin, beta-endorphin, Met-enkephalin or D-Met-Pro-enkephalinamide). The effect of cortisol was depressed by actinomycin D pretreatment. The cortisol-induced inhibition of the action of morphine was facilitated in adrenalectomized animals; measuring the effects of increasing doses of cortisol a maximal inhibition was obtained at a dose of 5 mg/kg. The opioid-induced corticosterone secretion was not affected 24 h after a single administration of cortisol. The present results show that the cortisol-induced inhibition of opioid-induced prolactin secretion is dependent on protein synthesis and independent of changes in drug metabolism, and of the type of opiate receptor preferentially affected by the opiate agonists employed.
Kiem
D T
DT
Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest.
Kanyicska
B
B
Stark
E
E
Fekete
M I
MI
D000315:Adrenalectomy; D000818:Animals; D002552:Cerebral Ventricles / Q000187:drug effects / Q000502:physiology*; D004399:Dynorphins / Q000494:pharmacology; D004723:Endorphins / Q000008:administration & dosage / Q000494:pharmacology*; D004744:Enkephalin, Methionine / Q000031:analogs & derivatives / Q000494:pharmacology; D006854:Hydrocortisone / Q000494:pharmacology*; D007276:Injections, Intraventricular; D008297:Male; D011388:Prolactin / Q000097:blood / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D012016:Reference Values; D001615:beta-Endorphin / Q000494:pharmacology
D004723:Endorphins; D004744:Enkephalin, Methionine; D001615:beta-Endorphin; C021717:enkephalin, Met(2)-ProNH2(5)-; D004399:Dynorphins; D011388:Prolactin; D006854:Hydrocortisone