Urinary gamma-glutamyl transferase as a specific marker for mercury after heavy metal treatment of rats.

Male Sprague--Dawley rats were injected i.p. with 1 mg heavy metal (Cu, Rb, Cs, Zn, Sr, Cd, Ba, Zr, Pb, Mb, Fe, Co, Ni)/kg body weight, as chlorides and 24 h urine samples were analysed for gamma-glutamyl transferase (GGT) content. Mercury (Hg) was the only metal that induced an enhanced urinary GGT activity. We concluded that, when acute metal intoxication has been observed, urinary GGT may function as a specific marker for Hg intoxication. Gel permeation studies showed that increased tubular lesion accounts for the Hg-induced GGT increase.