Spinal effects of alpha-endorphin in mice.
In male R-3 mice alpha-endorphin (alpha-E) was injected intracerebroventricularly (icv, 10 ng) or intrathecally (ith, 1 or 10 ng). The antinociceptive activity (tail immersion test) and the locomotor activity (photocell actometers) were measured. alpha-E administered icv or ith induced an evident antinociceptive effect which was prevented by the previous naloxone injection. Locomotor activity was inhibited by icv but not ith administration of alpha-E. This effect was not changed by naloxone. The results show that exogenous alpha-E elicits different effects when applied icv or ith, and induces antinociceptive effect at the spinal level through opioid receptors.
D000700:Analgesics; D000818:Animals; D004723:Endorphins / Q000008:administration & dosage* / Q000037:antagonists & inhibitors / Q000494:pharmacology; D007276:Injections, Intraventricular; D007278:Injections, Spinal; D008297:Male; D051379:Mice; D009043:Motor Activity / Q000187:drug effects*; D009270:Naloxone / Q000494:pharmacology; D018822:alpha-Endorphin
D000700:Analgesics; D004723:Endorphins; D009270:Naloxone; D018822:alpha-Endorphin