在部分不可逆受体失活后，利用不同激动剂对鱼类黑素细胞色素聚集α2-肾上腺素能受体进行表征。

Characterization of pigment aggregating alpha 2-adrenoceptors of fish melanophores by use of different agonists after partial irreversible receptor inactivation.

Karlsson J O, Andersson R G, Grundström N

Department of Pharmacology, Linköping University, Sweden.

Br J Pharmacol. 1989 May;97(1):222-8. doi: 10.1111/j.1476-5381.1989.tb11945.x.

Abstract

The affinity for, and the intrinsic efficacy on, postsynaptic melanosome aggregating alpha 2-adrenoceptors of fish melanophores was studied for B-HT 920, clonidine, medetomidine, noradrenaline, phenylephrine and UK-14,304. Investigations were carried out by evaluating the effects of progressive, irreversible inactivation of the alpha 2-adrenoceptors by benextramine. 2. The double reciprocal plots of equieffective concentrations of B-HT 920, clonidine, noradrenaline and phenylephrine were linear, which indicated that these compounds exerted their effects, mainly, through interaction with one receptor site. 3. The affinity for the alpha 2-adrenoceptor selective agonist B-HT 920, was found to be about 1000 times higher than the affinity for the alpha 1-adrenoceptor selective agonist phenylephrine. 4. The corresponding plot of equieffective concentrations of medetomidine was not linear, which may indicate that this imidazole compound exerted its effect through more than one receptor site. However, when phenoxybenzamine was used in place of the more selective benextramine, a linear relationship was obtained.

摘要

研究了B-HT 920、可乐定、美托咪定、去甲肾上腺素、苯肾上腺素和UK-14,304对鱼类黑素细胞突触后黑素体聚集α2肾上腺素能受体的亲和力及内在活性。通过评估贝那替秦对α2肾上腺素能受体进行渐进性、不可逆失活的影响来开展研究。2. B-HT 920、可乐定、去甲肾上腺素和苯肾上腺素等效浓度的双倒数图呈线性，这表明这些化合物主要通过与一个受体位点相互作用发挥其效应。3. 发现对α2肾上腺素能受体选择性激动剂B-HT 920的亲和力比对α1肾上腺素能受体选择性激动剂苯肾上腺素的亲和力高约1000倍。4. 美托咪定等效浓度的相应图不是线性的，这可能表明这种咪唑化合物通过多个受体位点发挥其效应。然而，当用酚苄明代替选择性更强的贝那替秦时，得到了线性关系。