The effect of mercuric chloride on the excretion of two urinary enzymes in the rat.

The effect of intravenous injections of HgCl2 on the renal excretion of alkaline phosphatase (AP) and leucine aminopeptidase (LAP) was investigated in rats. On the first day after Hg enzyme excretion showed a linear rise with the Hg dose from a threshold value of 0.44 mg Hg/kg. On the second day a statistically significant effect was seen already after 0.25 mg HgKG. After doses of 0.75 mg/kg or more a decrease of enzyme activity below control values occurred which persisted for more than 4 days. Treatment with 2,3-dimercaptopropansulfonate (DMPS) brought about a normalization of AP excretion. An effect on LAP excretion was observed only with early treatment. The same holds for the effect of DMPS on Hg-induced lethality. The usefulness of a measurement of LAP excretion for estimating the exposure to inorganic mercury is discussed.