Carpenter F G
Br J Pharmacol. 1977 Jan;59(1):43-9. doi: 10.1111/j.1476-5381.1977.tb06975.x.
The action of an anticholinesterase and an antimuscarinic drug upon nerve-induced contractions of the rat urinary bladder were examined during transmural stimulation at 20 Hz. Responses were graded in magnitude by limiting the duration of the stimulus trains. 2 Responses of low magnitude produced by short stimulus trains were unchanged by atropine; however, maximal responses resulting from long stimulus trains were diminished in magnitude and shortened in duration. 3 Responses of small magnitude elicited by short stimulus trains involve muscarinic receptors in close proximity to the neuroeffector junction and are resistant to atropine. 4 Maximal responses elicited by long stimulus trains involve 'junctional' muscarinic receptors as well as receptors located at the periphery of the junction; the 'extrajunctional' receptors are blocked by atropine. 5 Responses of low magnitude produced by short stimulus trains were unaffected by echothiophate; however, the duration of maximal responses resulting from the long stimulus trains was extended. 6 The inhibition of cholinesterase did not increase the occupation of muscarinic receptors by the transmitter; however, after large quantities of transmitter were released by the long stimulus trains the association between the receptors and acetylcholine was prolonged.
在20赫兹的跨壁刺激过程中，研究了抗胆碱酯酶药和抗毒蕈碱药对大鼠膀胱神经诱发收缩的作用。通过限制刺激串的持续时间来对反应幅度进行分级。2 短刺激串产生的低幅度反应不受阿托品影响；然而，长刺激串产生的最大反应幅度减小且持续时间缩短。3 短刺激串引发的小幅度反应涉及紧邻神经效应器接头的毒蕈碱受体，且对阿托品有抗性。4 长刺激串引发的最大反应涉及“接头处”毒蕈碱受体以及位于接头周边的受体；“接头外”受体被阿托品阻断。5 短刺激串产生的低幅度反应不受依可碘酯影响；然而，长刺激串产生的最大反应的持续时间延长。6 胆碱酯酶的抑制并未增加递质对毒蕈碱受体的占据；然而，在长刺激串释放大量递质后，受体与乙酰胆碱之间的结合延长。
