Graded intestinal vascular obstruction. II. Effects of antibiotic pretreatment in the rat

This study was performed to elucidate whether bacteria, or products of bacterial origin, could account for the circulatory collapse following a 1-hour intestinal vascular obstruction in the rat. Animals pretreated with clindamycin, in a way previously shown to induce characteristics otherwise found only in germ-free rats, were compared to controls pretreated with saline. Graded intestinal vascular obstruction was applied and four different pressure levels were used. Mortality increased with the applied pressure but there was no difference between the clindamycin-pretreated rats and controls. Hematocrit increased equally in all pressure levels and was not influenced by pretreatment. The amount of fluid lost from the serosal surface of the intestines was not correlated to the pretreatment used, the increase in hematocrit, or mortality. In the higher pressure levels, characteristic microscopic intestinal mucosal lesions were found in both series and the degree of mucosal damage correlated with increase mortality.