The mechanisms underlying nonspecific supersensitivity induced by parasympathetic denervation in rat iris sphincter

该机制根据非特定超敏感性诱导的机制，利用RT-PCR、半定量PCR和皮肤纤维技术进行了实验。它发现了AF 64 A的微注射，这是一种新颖的胆碱能放大抑制剂，并被发现为大鼠的非初级眼睛室，在虹膜精子光滑麝香类似物中的变化中，这些变化被外科性催眠去除的神经性肿瘤学。The changes were Management terized in vitro by reduced contractile response to nerve stimulation presumably via the decrease in acetylcholine （ACh） release from parasympathetic nerve endings and by enhanced contractile responses both specific to exogenously applied ACH and nonspecific to serotonin and high KイD1+イエD1。鼠虹膜中麝香受体的半定量PCR分析，即m2、m3和m4亚型的mRNAs在虹膜中表达，而且，出乎意料的是，m4的表达水平远远高于m2和m3。大鼠虹膜中的m2、m3和m4序列同源性报告了超过99%的大鼠基因组或cDNA中的其他蛋白质，而在发现的插入环中氨基酸序列中的若干差异。跟随AF 64 A的注射，m2和m3的mRNA水平增加，即m4减少，相应地减少。The CaイイD12+イエD1 sensitivity of the contractile machinery measured in skinned fiber was slightly but significantly increased by AF64A injection。Ca-I-D12+ I-D1敏感性的增加被添加到H7，蛋白激酶C抑制剂中。AF64A injection resulted in marked increase in the maximum contractile response of iris sphincter muscle。A Slight increase in in actin的数量，而在那些myosin和calmodulin in在虹膜中没有解释在最大的契约性反应中的增加。A novel Mechanism distinctive from the changes in may underlie the nonspecific supersensitivity induced by AF64A。

The mechanisms underlying nonspecific supersensitivity induced by parasympathetic denervation were examined using RT-PCR, semi-quantitative PCR and skinned fiber techniques. It was found that microinjection of AF64A, a novel choline uptake inhibitor, into anterior eye chamber of the rat resulted in changes in iris sphincter smooth muscle similar to those elicited by surgical parasympathetic denervation by removal of ciliary gangrionectomy. The changes were characterized in vitro by reduced contractile response to nerve stimulation presumably via the decrease in acetylcholine (ACh) release from parasympathetic nerve endings and by enhanced contractile responses both specific to exogenously applied ACh and nonspecific to serotonin and high KィイD1+ィエD1. Semi-quantitative PCR analyses of muscarinic receptors in rat iris indicate that mRNAs of m2, m3 and m4 subtypes are expressed in iris and that, unexpectedly, the expression level of m4 is much higher than that of m2 and m3. The sequence homology of m2, m3 and m4 in rat iris to those reported in genome or cDNA in other tissues of the rat was over 99%, while several differences in amino acid sequence in intracellular loops were found. Following the injection of AF64A, mRNA levels of m2 and m3 increased and that of m4 decreased, respectively. The CaィイD12+ィエD1 sensitivity of the contractile machinery measured in skinned fiber was slightly but significantly increased by AF64A injection. The increase in CaィイD12+ィエD1 sensitivity was abolished by addition of H7, protein kinase C inhibitor. AF64A injection resulted in marked increase in the maximum contractile response of iris sphincter muscle. A slight increase in amount of actin and no change in those of myosin and calmodulin in iris can not explain the increase in the maximum contractile response. A novel mechanism distinctive from the changes in major contractile and related regulatory proteins may underlie the nonspecific supersensitivity induced by AF64A.