Effect of neurotensin, substance P and morphine sulfate on the secretion of prolactin and growth hormone in the rat.
Neurotensin (NT), substance P (SP) and morphine sulfate (MS) elevate plasma prolactin and growth hormone levels in both normal or estrogen-progesterone pretreated male rats. By contrast, steroid priming is required for TRF to exhibit PRL-releasing activity. Naloxone, an opiate receptor blocker, reverses the stimulatory effect of MS only. Diphenhydramine, a histamine antagonist, inhibits the response to NT, SP and MS without affecting the response to TRF. These results suggest the involvement of a histaminic step in the action of NT, SP and MS. TRF, NT and SP do not appear to stimulate PRL and GH through activation of an opiate receptor.
D000818:Animals; D004155:Diphenhydramine / Q000494:pharmacology; D004967:Estrogens / Q000494:pharmacology; D013006:Growth Hormone / Q000378:metabolism*; D008297:Male; D009020:Morphine / Q000494:pharmacology*; D009270:Naloxone / Q000494:pharmacology; D009496:Neurotensin / Q000494:pharmacology*; D011374:Progesterone / Q000494:pharmacology; D011388:Prolactin / Q000378:metabolism*; D051381:Rats; D012636:Secretory Rate / Q000187:drug effects; D013373:Substance P / Q000494:pharmacology*; D013973:Thyrotropin-Releasing Hormone / Q000494:pharmacology
D004967:Estrogens; D013373:Substance P; D009270:Naloxone; D009496:Neurotensin; D011374:Progesterone; D013973:Thyrotropin-Releasing Hormone; D009020:Morphine; D004155:Diphenhydramine; D011388:Prolactin; D013006:Growth Hormone