Roger T, Bardon T, Ruckebusch Y
Laboratoire d'Anatomie, Ecole Nationale Vétérinaire de Lyon, France.
Can J Vet Res. 1994 Jul;58(3):163-6.
The electrical and mechanical activity of the large intestine and its response to administration of opiate mu and kappa agonists were assessed from electrodes and inductograph coils chronically implanted on the cecocolic segment in six ponies given a diet of hay and concentrates. Before the drugs were given, migrating complexes propagating from the cecum into the colon occurred at the rate of 1.5 to 16/hour. During this propulsive activity, the cecocolic sphincter opened and closed allowing the outflow of cecal contents and preventing the backflow of colic contents. Each pony was used as its own control and was given fentanyl (0.01 and 0.05 mg/kg of body weight, IV) and U50488H (0.1 and 0.5 mg/kg, IV) at weekly intervals. The mu agonist fentanyl elicited a marked phase of inhibition of the propulsive activity and a closure of the cecocolic sphincter that lasted one to two hours depending on the dose. The kappa agonist U50488H induced an inhibition of the short spiking activity, i.e. of the resting muscle tone. It did not disturb the occurrence of migrating complexes nor that of the openings of the cecocolic sphincter. These kappa compounds may be drugs of choice to alleviate visceral pain in colic stases without inducing delay of transit unlike mu compounds.
对6匹以干草和精饲料为食的小马，通过长期植入盲结肠段的电极和感应线圈，评估其大肠的电活动和机械活动以及对阿片μ和κ激动剂给药的反应。在给药前，从盲肠向结肠传播的移行性复合运动以每小时1.5至16次的速率发生。在这种推进活动期间，盲结肠括约肌打开和关闭，允许盲肠内容物流出并防止结肠内容物回流。每匹小马都作为自身对照，每周间隔静脉注射芬太尼（0.01和0.05mg/kg体重）和U50488H（0.1和0.5mg/kg）。μ激动剂芬太尼引起推进活动的显著抑制阶段以及盲结肠括约肌关闭，持续时间为1至2小时，具体取决于剂量。κ激动剂U50488H诱导短峰活动的抑制，即静息肌张力的抑制。它不干扰移行性复合运动的发生，也不干扰盲结肠括约肌的开放。与μ化合物不同，这些κ化合物可能是缓解结肠淤滞内脏疼痛而不引起转运延迟的首选药物。
