Thymidine kinase activity in liver and serum of rats after cadmium administration.

Intraperitoneal administration of a cadmium (Cd) salt at concentrations of 2.5 and 4.0 mg CdCl2/kg of body wt., caused time-dependent severe liver injury, in Quinster rats, more intense at the higher administered dose. Thymidine kinase, the key enzyme of the salvage pathway of DNA biosynthesis, was strongly affected in liver tissue and serum of cadmium-intoxicated rats. Lower thymidine kinase activity was observed both in liver and serum of rats treated with the higher dose of cadmium, in which the maximal liver injury appeared.