Kiernan J A, Heinicke E A
Department of Anatomy, University of Western Ontario, London, Canada.
Neuroscience. 1989;30(3):837-42. doi: 10.1016/0306-4522(89)90175-9.
Effects of senna on the myenteric plexus of the colon were investigated in view of earlier reports that this anthraquinone cathartic depletes the plexus of its intrinsic neurons. Rats and mice were given purgative doses of sennosides in their drinking water for 4 and 5 months, respectively. Body growth was reduced, and the weight of the colon with its contents was increased relative to the weight of the whole body in the treated animals. The latter change was attributed to depressed propulsive motility of the large intestine. Total numbers of myenteric neurons were determined from whole-mount preparations stained with Cuprolinic Blue-magnesium chloride, which selectively coloured the neuronal somata. The number of neurons in the rat's colon was unaffected by treatment with senna, but the colons of the treated mice contained significantly more neurons than those of their controls. Staining with antisera to 10 putative neurotransmitters or their associated enzymes revealed immunoreactive somata and axons in the myenteric plexus. Treatment with senna was not associated with absence of neuronal somata or fibres stainable with any of the antisera in either species. Thus, there was no evidence of toxic destruction of any identifiable population of neurons that might have been too small to affect the total counts. We conclude that senna does not kill myenteric neurons in the colon of the rat or mouse.
鉴于早期报道称这种蒽醌类泻药会使结肠肌间神经丛的固有神经元减少，本研究调查了番泻叶对结肠肌间神经丛的影响。分别给大鼠和小鼠在饮用水中给予泻下剂量的番泻苷，持续4个月和5个月。处理组动物的身体生长减缓，结肠及其内容物的重量相对于全身重量增加。后一种变化归因于大肠推进性运动减弱。通过用铜蓝蛋白-氯化镁染色的整装标本确定肌间神经元的总数，该方法可选择性地使神经元胞体着色。番泻叶处理对大鼠结肠中的神经元数量没有影响，但处理组小鼠的结肠中神经元数量明显多于对照组。用针对10种假定神经递质或其相关酶的抗血清染色，可在肌间神经丛中显示出免疫反应性胞体和轴突。番泻叶处理与两种动物中任何一种抗血清可染色的神经元胞体或纤维缺失均无关。因此，没有证据表明任何可识别的神经元群体受到毒性破坏，而这些神经元群体可能太小以至于无法影响总数。我们得出结论，番泻叶不会杀死大鼠或小鼠结肠中的肌间神经元。
