* GSH values are given as nmol / mg protein. Animals were fed with 2 mM BSO for 1, 2 or 3 weeks before injection with the different heavy metals, and the GSH content was evaluated at 3 and 5 days after the injection. Standard deviations did not exceed 5%. In brackets is the percentage of decrement of GSH levels relative to control untreated animals. Each value is the mean of 3 independent experiments, using 3 different animals.