Influence of long-term treatment with hydrazinophthalazines on the activity of lysosomal exoglycosidases in rat tissues.

Serum antinuclear antibodies were induced in rats by treatment with hydralazine or todralazine, given in daily dose of 25 mg/kg of body wt. for 12 months. An increased activity of alpha-glucosidase, beta-glucosidase, beta-galactosidase, alpha-fucosidase, beta-xylosidase was found in heart muscle, liver, kidney and lung. Hydralazine produced a more significant increase in the enzyme activity than todralazine. The obtained results suggest drug-induced connective tissue damage, probably of an inflammatory type. The mechanism of this phenomenon and its relationship to immunological alterations remain unclear.