Makanju O O
Methods Find Exp Clin Pharmacol. 1983 Nov;5(9):631-4.
The effects of some cholinomimetic and sympathomimetic drugs have been investigated on the isolated rectal muscles of West African rainbow lizard (Agama agama) and land tortoise (Kinixys crosa). Acetylcholine and its natural or synthetic analogues evoked concentration-related atropine-sensitive contractions of the muscle preparations, whereas all the catecholamines examined relaxed the lizard (and guinea-pig), but not the tortoise, isolated rectum in a dose-dependent fashion. The ganglionic stimulant drugs used, nicotine and DMPP, did not produce any effect on the isolated rectum of the two reptiles, although they contracted the guinea-pig isolated rectum in a concentration-dependent manner. Concentrations of physostigmine, which induced spasms or contractions in the isolated rectum of the guinea-pig, failed to excite reptilian rectal muscle preparations. Histamine induced biphasic responses in the lizard isolated rectum without affecting the isolated rectum of the tortoise. Serotonin (5-HT) which contracted the isolated rectum of the guinea-pig (like histamine) also provoked variable contractions of the lizard rectum but did not affect the tortoise isolated rectum. It is therefore concluded that although the rectal smooth muscles of these two terrestrial West African reptiles possess cholinergic innervation with mainly "muscarinic" cholinoceptors, their autonomic innervation differs from that of a conventional mammalian (e.g. guinea-pig) gastrointestinal tract smooth muscle.
已经研究了一些拟胆碱药和拟交感神经药对西非彩虹蜥蜴（变色蜥）和陆龟（克罗氏动胸龟）离体直肠肌肉的作用。乙酰胆碱及其天然或合成类似物可引起肌肉制剂浓度相关的对阿托品敏感的收缩，而所有检测的儿茶酚胺均以剂量依赖性方式使蜥蜴（和豚鼠）的离体直肠松弛，但对陆龟的离体直肠无此作用。所用的神经节兴奋药尼古丁和二甲基苯基哌嗪对这两种爬行动物的离体直肠没有任何作用，尽管它们能使豚鼠离体直肠以浓度依赖性方式收缩。毒扁豆碱在豚鼠离体直肠中可引起痉挛或收缩，但其浓度未能使爬行动物直肠肌肉制剂兴奋。组胺在蜥蜴离体直肠中引起双相反应，但不影响陆龟的离体直肠。血清素（5-羟色胺）能使豚鼠离体直肠收缩（与组胺类似），也能引起蜥蜴直肠不同程度的收缩，但不影响陆龟的离体直肠。因此得出结论，尽管这两种西非陆生爬行动物的直肠平滑肌具有胆碱能神经支配，主要是“毒蕈碱型”胆碱受体，但其自主神经支配与传统哺乳动物（如豚鼠）胃肠道平滑肌的自主神经支配不同。
