Endotoxin studies in chicks: effect of lead acetate.

Lead acetate administered intravenously in a mixture with endotoxin preparations potentiates the toxic effect of endotoxin for 14-21 day old meat strain chicks. A dose of 2.8 mg of lead acetate/100 g body weight is more effective with endotoxin than a dose of 2.5 mg; however, a dose of 3.0 mg or greater is toxic alone. The degree of potentiation appears to be at least 1000 fold and permits toxicity determinations using endotoxin levels ranging from 0.125 microg to 250 microg/chick. Endotoxin preparations made using NaCl, TCA or phenol-water extraction procedures, possessed toxic activity for chicks when tested by this method.