Ketogenesis evaluation in perfused liver of diabetic rats submitted to short-term insulin-induced hypoglycemia

Ketogenesis, inferred by the production of acetoacetate plus ss-hydroxybutyrate, in isolated perfused livers from 24-h fasted diabetic rats submitted to short-term insulin-induced hypoglycemia (IIH) was investigated. For this purpose, alloxan-diabetic rats that received intraperitoneal regular insulin (IIH group) or saline (COG group) injection were compared. An additional group of diabetic rats which received oral glucose (gavage) (100 mg kg(-1)) 15 min after insulin administration (IIH + glucose group) was included. The studies were performed 30 min after insulin (1.0 U kg(-1)) or saline injection. The ketogenesis before octanoate infusion was diminished (p < 0.05) in livers from rats which received insulin (COG vs. IIH group) or insulin plus glucose (COG vs. IIH + glucose group). However, the liver ketogenic capacity during the infusion of octanoate (0.3 mM) was maintained (COG vs. IIH group and COG vs. IIH + glucose group). In addition, the blood concentration of ketone bodies was not influenced by the administration of insulin or insulin plus glucose. Taken together, the results showed that inspite the fact that insulin and glucose inhibits ketogenesis, livers from diabetic rats submitted to short-term IIH which received insulin or insulin plus glucose showed maintained capacity to produce acetoacetate and ss-hydroxybutyrate from octanoate.