Hayes A, Kelly A
Eur J Pharmacol. 1985 Apr 16;110(3):317-22. doi: 10.1016/0014-2999(85)90558-8.
The purpose of this study was to investigate further the kappa opioid receptor selectivity of the field-stimulated isolated rabbit vas deferens preparation and to study the profile of a series of kappa agonists in this tissue. Agonists acting at mu, delta and sigma receptors were without detectable effect in the rabbit vas deferens. But a number of kappa agonists, including bremazocine, tifluadom, ethylketocyclazocine, ketocyclazocine, U-50,488 and Win 42,610 all depressed contractions, producing parallel dose-response curves. Mr 2034 generally produced a shallower dose-response curve and achieved a lower maximum effect, thus acting like a partial agonist. The effect of ethylketocyclazocine was not reduced by the irreversible mu antagonist, beta-funaltrexamine, confirming that it is not acting via mu receptors. Another group of drugs, including nalorphine, butorphanol and proxorphan, which produce an agonist action via kappa receptors in the guinea-pig ileum and mouse vas deferens, were antagonists in the rabbit vas deferens, suggesting that this tissue will only respond to high efficacy kappa agonists.
本研究的目的是进一步研究场刺激离体兔输精管制剂对κ阿片受体的选择性，并研究该组织中一系列κ激动剂的作用情况。作用于μ、δ和σ受体的激动剂在兔输精管中未产生可检测到的效应。但包括布马佐辛、替氟朵、乙基酮环佐辛、酮环佐辛、U-50,488和Win 42,610在内的多种κ激动剂均能抑制收缩，产生平行的剂量-反应曲线。Mr 2034通常产生较浅的剂量-反应曲线，且最大效应较低，因此表现为部分激动剂。乙基酮环佐辛的效应不会被不可逆的μ拮抗剂β-芬太尼所减弱，这证实其作用并非通过μ受体。另一组药物，包括纳洛啡、布托啡诺和丙氧芬，在豚鼠回肠和小鼠输精管中通过κ受体产生激动作用，但在兔输精管中却是拮抗剂，这表明该组织仅对高效能的κ激动剂有反应。
