Suppressive effect of beta-endorphin on body shaking response to ice water immersion and synergistic action of vasoactive intestinal peptide on beta-endorphin in anesthetized rats.
The effects of beta-endorphin and vasoactive intestinal peptide (VIP) on the body shaking response to ice water immersion were observed in anesthetized rats. Intraventricular injection of beta-endorphin markedly inhibited body shaking, but gamma- and alpha-endorphin and methionine-enkephalin showed only slight or little effect. VIP also suppressed the body shaking. The inhibitory effect of beta-endorphin and VIP was blocked by naloxone. When small doses of beta-endorphin and VIP which could not affect the shaking behavior by themselves were administered simultaneously, significant suppression occurred, indicating potentiation of the effect of beta-endorphin by VIP.
D000818:Animals; D004357:Drug Synergism; D004723:Endorphins / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D004744:Enkephalin, Methionine / Q000494:pharmacology; D007053:Ice; D007101:Immersion / Q000503:physiopathology; D008297:Male; D009270:Naloxone / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D012768:Shivering / Q000187:drug effects*; D014660:Vasoactive Intestinal Peptide / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D018822:alpha-Endorphin; D001615:beta-Endorphin; D018823:gamma-Endorphin
D004723:Endorphins; D007053:Ice; D009270:Naloxone; D014660:Vasoactive Intestinal Peptide; D004744:Enkephalin, Methionine; D001615:beta-Endorphin; D018822:alpha-Endorphin; D018823:gamma-Endorphin