Penicillamine and vitamin B6 interrelationships in the rat.

DL-Penicillamine administered in the diet at the 0.25% level produced a marked lowering of food intake and body weight. Using blood transaminase activities as criteria, a definite antagonism to vitamin B6 was demonstrated. The response of animals to the drug did not differ between sexes. Transaminase activity changes were apparent within 13 days of treatment. They were not the result of a reduced food intake. Administration of 800 μg of pyridoxine hydrochloride per 10 g of diet to animals receiving penicillamine approximated the maximal prevention of the effects of the drug upon food intake, body weight, and transaminase activity. The effects were not completely prevented by dosages of vitamin B6 as high as 2000 μg per 10 g of diet. Attention is drawn to the possible significance of these studies in the treatment of patients (Wilson's disease) with penicillamine. On the basis of extrapolations from the present studies in rats, 50 mg of pyridoxine hydrochloride might be expected to give near-maximal protec...