内毒素对冠状动脉循环的效应

Effects of Endotoxin on Coronary Circulation

本实验以猪为模型，探讨败血症性休克的主要毒素──内毒素对冠状动脉（冠脉）循环的影响。从静脉输注内毒素，浓度为４ｎｇ／ｍｌ按每分钟０．３ｎｇ／ｋｇ持续输入。该剂量内毒素未引起血压下降，也不损害冠脉的自动调节功能，冠脉流量保持恒定。但当冠脉灌注压降至４．６７ｋＰａ时，内毒素使冠脉流量增加（输注前和后分别为６２．５±２９．２和８９．５±３２．７ｍｌ／ｍｉｎ，Ｐ＜０．０５）。对内毒素增加冠脉流量的可能机理进行了初步探讨。

To investigate the effects of endotoxin(ETX) on coronary circulation,we infused endotoxin(4ng/ml)intravenously in a small dose(0. 3ng/kg.min￣(-1))which did not reduce the blood presssure, nordid it disturb the coronary autoregulation,and theflow kept constant during the ETX infusion, But whenthe left coronary artery descending branch(LAD) wasnarrowed and the LAD pressure was reduced to 4.67kPa,the ETX showed a vasodilator effect on the LAD(pre-ETX 65.2±29. 2 ml/min, post-ETX 89.5±32.7ml/min,P<0.05)This effect suggested that theETX in a small dose bad a vasodilator effect on a nar-rowed coronary artery,even when it did not disturbthe hemodynamics. The possible mechanisms weresurveyed preliminarily.