Caerulein and cholecystokinin suppress beta-endorphin-induced analgesia in the rat.
The analgesic action of beta-endorphin, as observed in the hot plate test with rats, was effectively suppressed by intracerebroventricular (i.c.v.) injection of caerulein and cholecystokinin octapeptide (CCK-8). The effect of caerulein was particularly striking; this peptide in doses of more than 0.09 nM lessened or abolished the analgesic effect of beta-endorphin in a dose of 0.7 nM. On the other hand, non sulfated CCK-8 had no significant effect on beta-endorphin-induced analgesia.
D000698:Analgesia; D000818:Animals; D002108:Ceruletide / Q000494:pharmacology*; D002766:Cholecystokinin / Q000494:pharmacology*; D004723:Endorphins / Q000037:antagonists & inhibitors*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D001615:beta-Endorphin
D004723:Endorphins; D001615:beta-Endorphin; D002108:Ceruletide; D002766:Cholecystokinin