Suppressive Effect of β-Endorphin on Body Shaking Response to Ice Water Immersion and Synergistic Action of Vasoactive Intestinal Peptide on β-Endorphin in Anesthetized Rats

抄録

The effects of β-endorphin and vasoactive intestinal peptide (VIP) on the body shaking response to ice water immersion were observed in anesthetized rats. Intraventricular injection of β-endorphin markedly inhibited body shaking, but γ- and α-endorphin and methionine-enkephalin showed only slight or little effect. VIP also suppressed the body shaking. The inhibitory effect of β-endorphin and VIP was blocked by naloxone. When small doses of β-endorphin and VIP which could not affect the shaking behavior by themselves were administered simultaneously, significant suppression occurred, indicating potentiation of the effect of β-endorphin by VIP.