Effect of subacute administration of isoniazid and pyridoxine on lipids in plasma, liver and adipose tissues in the rabbit.

The effect of subacute intraperitoneal administration of Isoniazid (INH) on various lipid parameters was studied in liver and adipose tissue in addition to plasma. In the liver, its effect on various phospholipid fractions was also assessed. The changes in lipid profile reflected INH-induced hepatic steatosis. While pyridoxine alone did not alter any of these lipid parameters, its concurrent administration with INH prevented almost all the INH-induced lipid changes. The enhanced lipid mobilization into liver, and a fall in phosphatidylcholine with a concomitant rise in phosphatidylethanolamine in liver impeding lipoprotein synthesis, might be responsible for the hepatic steatosis. Pyridoxal, a pyridoxine metabolite, might have trapped the primary amine functional group of acetylhydrazine and thus prevented the steatosis.