title: Urinary taurine as a non-invasive marker of aflatoxin B1-induced hepatotoxicity: success and failure.
abstract: The usefulness of urinary taurine as a non-invasive measure of hepatotoxicity of aflatoxin B1 (AFB1) was evaluated: changes in urinary taurine 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 after, the treatment with AFB1. Rats received a single p.o. dose of 0, 0.25, 0.5, 1, 2 or 3 mg AFB1/kg body wt. A transient increase in urinary taurine was noted with doses of 1, 2 or 3 mg AFB1/kg. In two sub-chronic exposure experiments, rats were gavaged with 25 microg AFB1/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 urinary taurine during 5 successive doses of AFB1 was observed, while in the second experiment, urinary taurine rose continuously during the 2 weeks of the AFB1 treatment. An explanation for these differing results is not obvious. Urinary taurine appeared to be a useful, non-invasive marker when hepatotoxicity was extensive. Unfortunately, at the low doses of AFB1 (0.25-0.5 mg/kg) as used in carcinogenesis experiments (10 doses of 25 microg/rat), urinary taurine appeared to be an insensitive measure of hepatic damage.
authors.affiliation: Department of Pharmacology and Toxicology, Dartmouth Medical School, Hanover, NH 03755, USA.
authors.forename: Y Y
authors.initials: YY
authors.lastname: Maxuitenko
authors.forename: W G
authors.initials: WG
authors.lastname: North
authors.forename: B D
authors.initials: BD
authors.lastname: Roebuck
mesh_terms: D000284:Administration, Oral; D016604:Aflatoxin B1 / Q000008:administration & dosage / Q000633:toxicity*; D000410:Alanine Transaminase / Q000097:blood; D000596:Amino Acids / Q000652:urine; D000818:Animals; D015415:Biomarkers / Q000652:urine; D001835:Body Weight / Q000187:drug effects; D002273:Carcinogens / Q000633:toxicity*; D048429:Cell Size / Q000187:drug effects; D002940:Circadian Rhythm; D004305:Dose-Response Relationship, Drug; D004326:Drinking / Q000187:drug effects; D004435:Eating / Q000187:drug effects; D007064:L-Iditol 2-Dehydrogenase / Q000097:blood; D008099:Liver / Q000187:drug effects* / Q000201:enzymology / Q000473:pathology; D008297:Male; D009929:Organ Size / Q000187:drug effects; D011041:Poisoning / Q000401:mortality; D051381:Rats; D011916:Rats, Inbred F344; D013654:Taurine / Q000652:urine*
chemical_list: D000596:Amino Acids; D015415:Biomarkers; D002273:Carcinogens; D013654:Taurine; D016604:Aflatoxin B1; D007064:L-Iditol 2-Dehydrogenase; D000410:Alanine Transaminase