THE EFFECT OF CERTAIN SULPHONYLUREA DRUGS ON PANTOTHENIC ACID METABOLISM IN THE RAT

Abstract

Small amounts of chlorpropamide in the diet (125 mg/kg) did not affect the growth response of rats given pantothenic acid deficient or normal diets. The growth-retarding effect of 1000 mg chlorpropamide/kg of diet was not overcome by the addition of excess pantothenic acid to the diet. The hypoglycemic responses of normal and pantothenic acid deficient animals to insulin were similar, but the effect of tolbutamide on blood sugar levels was significantly less in pantothenic acid deficient animals than in normal controls. The acetylation of an intraperitoneally administered dose of sulphanilamide was significantly lowered when normal rats were given a concomitant oral dose of tolbutamide or propylthiouracil, but was unaffected by phenformin or insulin. Although pantothenic acid deficient animals acetylated less sulphanilamide than normal animals, the percentage of acetylation was not reduced further by treatment with tolbutamide.It was concluded that tolbutamide and chlorpropamide apparently influence certain aspects of pantothenic acid metabolism in the rat, but is unlikely to influence significantly the over-all requirements for the vitamin.