Siniscalchi A, Bianchi C
Dept. of Pharmacology, University of Ferrara, Italy.
Pharmacol Res Commun. 1988 Jan;20(1):73-85. doi: 10.1016/s0031-6989(88)80608-8.
The effect of ethylketocyclazocine (EKC) on 3H-Choline (Ch) efflux and on endogenous acetylcholine (ACh) release from guinea-pig brain slices was studied. The drug inhibited the 3H-Ch efflux at a low concentration (0.1 mumol/l) in thalamus slices, while only at high concentrations (30-100 mumol/l) did EKC induce deep inhibition in the caudate nucleus and slight reduction in the cerebral cortex. Dynorphin (1-13) and morphine (Mo) inhibited the ACh release from thalamus slices as well. Naloxone (Nx) was more effective in antagonizing Mo than EKC. The experiments carried out with the endogenous ACh bioassay technique confirmed the above results. Mr 2266 and Mr 1452, both proposed as preferential k antagonists, per se enhanced 3H-Ch efflux from thalamus slices, while the dextrorotatory isomer Mr 1453, devoid of opioid properties, did not share such action. The role of k-opioid receptors in cholinergic system modulation in the guinea-pig brain is discussed.
研究了乙基酮环唑辛（EKC）对豚鼠脑片3H-胆碱（Ch）外流以及内源性乙酰胆碱（ACh）释放的影响。该药物在低浓度（0.1μmol/L）时抑制丘脑切片中的3H-Ch外流，而仅在高浓度（30 - 100μmol/L）时，EKC才会在尾状核中诱导深度抑制，并使大脑皮层略有降低。强啡肽（1 - 13）和吗啡（Mo）也抑制丘脑切片中的ACh释放。纳洛酮（Nx）在拮抗Mo方面比EKC更有效。采用内源性ACh生物测定技术进行的实验证实了上述结果。两种被认为是选择性κ拮抗剂的Mr 2266和Mr 1452本身增强了丘脑切片中的3H-Ch外流，而不具有阿片样特性的右旋异构体Mr 1453则没有这种作用。讨论了κ阿片受体在豚鼠脑胆碱能系统调节中的作用。
