DIABETES-INDUCED ALTERATION OF HMGCOA REDUCTASE FORMS IN RAT LIVERS

The effects of streptozotocin-induced diabetes on the various forms of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCoA reductase), p hosphorylated/dephosphorylated and thiolic/disulphide, were studied in rat liver. Animals were treated twice with 65 mg/kg intraperitoneally of streptozotocin to induce diabetes and sacrificed after 5 days. The relative amounts of the four possible forms of the enzyme were determ ined in control and diabetic rats. As determined from the total activi ty, and in agreement with previous reports, the enzyme protein was sig nificantly decreased in streptozotocin-treated rats. However, the perc entage of the active thiolic dephosphorylated form was higher in these animals than in controls, suggesting a response of the liver to the d ecrease both total and specific activity of HMGCoA reductase.