Fruhwald S, Herk E, Schöll G, Shahbazian A, Hammer H F, Metzler H, Holzer P
Department of Anaesthesiology and Intensive Care Medicine, Medical University of Graz, Graz, Austria.
Neurogastroenterol Motil. 2004 Apr;16(2):213-22. doi: 10.1111/j.1365-2982.2004.00509.x.
The action of endotoxin to alter gastrointestinal motility in vivo may reflect a direct effect on the gut or result from vascular and other systemic manifestations of this sepsis model. Here we examined whether in vivo pretreatment of guinea-pigs with endotoxin modifies peristalsis in the isolated gut and influences the antipropulsive action of adrenoceptor agonists. Distension-induced peristalsis was recorded in fluid-perfused segments of the small intestine taken from animals pretreated intraperitoneally with endotoxin (1 mg kg(-1)Escherichia coli lipopolysaccharide) or vehicle 4 or 20 h before. Clonidine, adrenaline, noradrenaline, dopamine and dobutamine inhibited peristalsis with differential potency. Endotoxin pretreatment lowered the peristaltic pressure threshold and altered other parameters of baseline peristalsis in a time-related manner. The potency and efficacy of clonidine to inhibit peristalsis were markedly decreased after endotoxin administration, while the potency of the other test drugs was less attenuated. The antipropulsive action of clonidine in control segments was reduced by yohimbine and prazosin, whereas in segments from endotoxin-pretreated animals it was antagonized by yohimbine but not prazosin. We conclude that systemic endotoxin pretreatment of guinea-pigs modifies baseline peristalsis by an action on the gut and inhibits the antipropulsive action of adrenoceptor agonists through changes in adrenoceptor activity.
内毒素在体内改变胃肠动力的作用可能反映了其对肠道的直接影响，或者是由该脓毒症模型的血管及其他全身表现所致。在此，我们研究了豚鼠体内预先给予内毒素是否会改变离体肠道的蠕动，并影响肾上腺素能受体激动剂的抗蠕动作用。记录从腹腔内预先给予内毒素（1 mg kg⁻¹ 大肠杆菌脂多糖）或赋形剂4或20小时前的动物获取的小肠液体灌注节段中扩张诱导的蠕动。可乐定、肾上腺素、去甲肾上腺素、多巴胺和多巴酚丁胺以不同效力抑制蠕动。预先给予内毒素会降低蠕动压力阈值，并以时间相关的方式改变基线蠕动的其他参数。给予内毒素后，可乐定抑制蠕动的效力和效能显著降低，而其他受试药物的效力减弱程度较小。在对照节段中，可乐定的抗蠕动作用可被育亨宾和哌唑嗪减弱，而在预先给予内毒素动物的节段中，其抗蠕动作用仅被育亨宾拮抗，而不被哌唑嗪拮抗。我们得出结论，豚鼠全身性预先给予内毒素通过作用于肠道改变基线蠕动，并通过肾上腺素能受体活性的变化抑制肾上腺素能受体激动剂的抗蠕动作用。
