beta-endorphin inhibits and facilitates lordosis behaviour in rats depending on ventricular site of administration.
beta-endorphin was administered intracerebroventricularly into the lateral and third ventricles of ovariectomized, oestrogen- and progesterone-primed rats, and its effect on lordosis and ear-wiggling was assessed. A dose of 2 micrograms beta-endorphin facilitated lordosis when infused into the lateral ventricle, but inhibited lordosis when infused into the third ventricle. The effects were the same whether measured at 30, 60 or 90 min following infusion. beta-endorphin had no significant effect on ear-wiggling frequency when administered in either ventricle. The differential effects of beta-endorphin depending on site of administration may reflect the activation of distinct opioid receptor subtypes within the brain.
Gorzalka
B B
BB
Department of Psychology, University of British Columbia, Vancouver, Canada. bgorzalka@neuron3.psych.ubc.ca
Heddema
G M
GM
Lester
G L
GL
Hanson
L A
LA
D000704:Analysis of Variance; D000818:Animals; D005260:Female; D007276:Injections, Intraventricular; D011187:Posture; D051381:Rats; D017207:Rats, Sprague-Dawley; D012726:Sexual Behavior, Animal / Q000187:drug effects*; D001615:beta-Endorphin / Q000494:pharmacology*
D001615:beta-Endorphin