[Cholecystokinin octapeptide antagonized the effect of NDAP on CaM in rat dorsal spinal synaptosome].
To elucidating the molecular mechanisms underlying CCK-8 anti-opioid effects, we have observed the effects and interactions of CCK-8 and kappa opiate agonist NDAP on CaM activity in rat dorsal spinal cord synaptosomes. The result indicated that 10 nmol/L-1 mumol/L NDAP produced dose-dependent decrease in CaM activity of rat spinal synaptosomes (P < 0.01). This suppressive effect was completely blocked by specific kappa receptor antagonist Nor-BNI at 1 mumol/L. In contrast, CCK-8 (10-100 nmol/L) induced a significant increase in CaM activity (P < 0.05-0.01), and was capable of antagonizing the suppressive effect induced by NDAP. Specific CCK-B receptor antagonist L365, 260 could partially block the effects of CCK-8 increased CaM activity at 1 mumol/L. The above results suggest that CCK-8 can antagonize the suppressive effect of NDAP on CaM activity in rat spinal synaptosomes via activation of CCK-B receptor, an effect that may constitute one of the mechanisms for the anti-opioid activity of CCK-8.
Chen
S Z
SZ
Department of Physiology, Beijing Medical University.
Han
J S
JS
D000818:Animals; D002147:Calmodulin / Q000502:physiology*; D004399:Dynorphins / Q000037:antagonists & inhibitors*; D005260:Female; D008297:Male; D010446:Peptide Fragments / Q000037:antagonists & inhibitors*; D051381:Rats; D017208:Rats, Wistar; D012844:Sincalide / Q000494:pharmacology*; D013116:Spinal Cord / Q000378:metabolism; D013574:Synaptosomes / Q000502:physiology*
D002147:Calmodulin; D010446:Peptide Fragments; C061285:E 2078; D004399:Dynorphins; D012844:Sincalide