Graded intestinal vascular obstruction. III. An analysis of pathogenic mechanisms.

A standardized model allowing graded obstruction of the intestine and its vascular supply was used in rats. Application of high pressures (100 and 120 cm of water) has previously been found to induce high mortality and intestinal mucosal lesions. This study was performed to elucidate the possible importance of nervous depressor reflexes and release of cardiotoxic material in the pathogenesis of the induced circulatory collapse. Denervation of the intestines made the blood pressure reduction during the period of obstruction less pronounced. Intestinal venous plasma obtained following one hour of obstruction with high pressure had a significant inhibitory effect when tested on isolated rabbit papillary muscles as compared to plasma obtained following obstruction with lower pressure. Pretreatment with clindamycin had no effect on this variable. It is suggested that the release of cardiotoxic factors is one pathogenetic factor in the development of the circulatory collapse following intestinal shock.