Effects of simultaneous treatment with PMX-DHP and sivelestat on endotoxaemia in conscious guinea pigs

Abstract

Using an endotoxaemia model in conscious guinea pigs, we previously reported that polymyxin B immobilized fiber-direct hemoperfusion (PMX-DHP) or administration of sivelestat are effective treatments for sepsis. In the present study, we investigated whether simultaneous treatment with PMX-DHP and sivelestat sodium was more effective than either treatment alone for sepsis. Measurements examined included intestinal paralysis, blood pressure, serum HMGB1 level and survival rate. Colonic motion was monitored continuously by telemetry using a transducer attached to the taenia caecum, while blood pressure was monitored with a carotid artery catheter. The guinea pigs were divided into 4 groups and lipopolysaccharide (LPS) was administered to all animals. The control group received only LPS. The remaining three groups received PMX treatment for 2 hours, sivelestat sodium administration for 2 hours or simultaneous PMX and sivelestat treatment for 2 hours. In the control group, decreased colonic muscle tension and arterial pressure, and increased serum HMGB1 levels were observed and all animals died within 30 hours. In the PMX-DHP treated group, the decreases in colonic tension and arterial pressure were less severe than for the control group and the survival rate was higher than the control group, but serum HMGB1 levels were not significantly different. In the sivelestat group, decreases in colonic tension and arterial pressure were not significantly different with the control group, but serum HMGB1 levels were lower than in the control group. Simultaneous treatment with both PMX-DHP and sivelestat sodium did not exhibit synergistic effects for the treatment of LPS- induced endotoxaemia and mortality. PMX-DHP was effective at treating sepsis induced by administration of a high dose of LPS in guinea pigs, but simultaneous administration of sivelestat sodium did not augment the efficacy of PMX-DHP treatment.