Effects of Lead Acetate on Sensitivity to Shock,Intravascular Carbon and Endotoxin Clearances,and Hepatic Endotoxin Detoxification 1

Abstract

Summary

Lead acetate iv at 5 mg/300 g to male rats of the Holtzman strain sensitized to the lethal shock induced by endotoxin, Noble-Collip tumbling trauma, hind limb ischemia, bowel ischemia, and horse serum anaphylaxis. Lead treatment depressed the intravascular phagocytic clearance of colloidal carbon as evaluated at 15, 30, 60, 120 and 240 min. By use of an endotoxin bioassay based on lethality in lead-treated assay rats, the intravascular removal of a test dose of 0.5 mg of endotoxin was not altered by lead treatment as compared to normal and sodium acetate treated controls. The ability of liver homogenates to detoxify endotoxin was not altered by lead administration at 0.5, 1, 2, 3, or 8 hr prior to sacrifice. The in vitro addition of lead to homogenates incubated with endotoxin did not alter detoxification. It is suggested that the mechanism of lead sensitization to endotoxin probably does not reflect alteration in its rate of clearance or detoxification but rather may relate to lead's ability to alter metabolic responses during endotoxemia.