[Effects of kappa-opiate receptor antagonist MR-2266-BS on ACTH and prolactin release].
The effect of intravenous injection of different doses of MR-2266-BS, a selective antagonist of kappa-opiate receptor, on plasma adrenocorticotropin (ACTH) and prolactin (PRL) in conscious male rats bearing an intrajugular cannulae was assessed. The results revealed that the MR-2266-BS of 3 mg/kg completely blocked the restraint stress-induced increase in plasma ACTH levels, and further elevated plasma PRL levels in these animals, while there were no effects on the resting levels of ACTH and PRL. MR-2266-BS of 6 mg/kg significantly increased the resting levels of plasma ACTH and also further elevated the restraint stress-induced increase of plasma ACTH and PRL. The present data suggest that kappa-opiate receptor and its endogenous ligand may be involved in the regulation of the resting and restraint stress-induced release of ACTH, and their action appears to be both stimulatory and inhibitory. Furthermore, kappa-opiate receptor and its endogenous ligand may only inhibit the stress-induced release of PRL.
Xu
R K
RK
Chen
L
L
Li
H
H
Yang
S J
SJ
Huang
X Y
XY
D000324:Adrenocorticotropic Hormone / Q000378:metabolism*; D000818:Animals; D001575:Benzomorphans / Q000494:pharmacology*; D008297:Male; D009019:Morphinans / Q000494:pharmacology*; D009020:Morphine / Q000037:antagonists & inhibitors; D011388:Prolactin / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D011957:Receptors, Opioid / Q000187:drug effects*; D017473:Receptors, Opioid, kappa
D001575:Benzomorphans; D009019:Morphinans; D011957:Receptors, Opioid; D017473:Receptors, Opioid, kappa; C027247:MR 2266; D009020:Morphine; D000324:Adrenocorticotropic Hormone; D011388:Prolactin