URINARY TAURINE AS A NONINVASIVE MARKER OF AFLATOXIN B-1-INDUCED HEPATOTOXICITY - SUCCESS AND FAILURE

The usefulness of urinary taurine as a non-invasive measure of hepatot oxicity of aflatoxin B-1 (AFB(1)) was evaluated: changes in urinary ta urine were characterized in a dose-response, acute toxicity experiment and in two sub-chronic, low dose exposure experiments. Urine of young , male, F344 rats was collected for 4 days prior to, and for 3 days af ter, the treatment with AFB(1). Rats received a single p.o. dose of 0, 0.25, 0.5, 1, 2 or 3 mg AFB(1)/kg body wt. A transient increase in ur inary taurine was noted with doses of 1, 2 or 3 mg AFB(1)/kg. In two s ub-chronic exposure experiments, rats were gavaged with 25 mu g AFB(1) /day for 5 successive days per week for 1 or 2 weeks (approximately 0. 25 mg/kg/day). In the first experiment, only a transient increase in u rinary taurine during 5 successive doses of AFB(1) was observed, while in the second experiment, urinary taurine rose continuously during th e 2 weeks of the AFB(1) treatment. An explanation for these differing results is not obvious. Urinary taurine appeared to be a useful, non-i nvasive marker when hepatotoxicity was extensive. Unfortunately, at th e low doses of AFB(1) (0.25-0.5 mg/kg) as used in carcinogenesis exper iments (10 doses of 25 mu g/rat), urinary taurine appeared to be an in sensitive measure of hepatic damage. (C) 1997 Elsevier Science Ireland Ltd.