Kidney urokinase activity following acute exposure to lead.

Urokinase activity was measured in kidney homogenate fractions obtained 2 days after injecting rats with 0.5 mg Pb2+/100 g body weight. The activity was higher in the membrane-containing fractions than in the soluble supernatant fractions and was markedly higher in the preparations derived from the lead-treated rats. The kidney poly(A)+ RNA was obtained from these animals and translated in a rabbit reticulocyte lysate system. In the preparations obtained from the lead-treated rats, there was an increased synthesis of a protein, believed to be urokinase, of pl 8.6 and molecular weight (Mr) 45,000.