UPTAKE OF KETONE-BODIES IN PERFUSED HINDQUARTER AND KIDNEY OF STARVED, THYROTOXIC, AND DIABETIC RATS

To elucidate the peripheral disposal of ketone bodies in hyperketonemi a accompanied with starvation, hyperthyroidism, or diabetes mellitus, the uptake of acetoacetic acid (AcAc) and beta-hydroxybutyrate (BOHB) was investigated in the perfused hindquarter and kidney of starved, th yrotoxic, and diabetic rats. Thyrotoxicity was induced by daily subcut aneous injection of thyroxine (100 mug/kg/day) for 7 days, and diabete s mellitus was induced by intraperitoneal streptozotocin (50 mg/kg) in jection. Plasma concentration of AcAc and BOHB was significantly highe r in starved, thyrotoxic, and diabetic rats than in controls. The hind quarter or kidney of rats was perfused with synthetic medium containin g 0.2 or 1.5 mM AcAc or BOHB for 30 min at a flow rate of 0.5 ml/g mus cle wt/min or 3.2-3.5 ml/kidney/min, respectively. In perfused hindqua rter, the uptake of AcAc and BOHB was significantly reduced in starved and diabetic rats, but not in thyrotoxic rats. In perfused kidney, th e uptake of AcAc and BOHB was not significantly different between the experimental and control rats. These results suggest that in starvatio n or diabetes mellitus, disposal of AcAc and BOHB was impaired in the hindquarter but not in the kidney, and that disposal of AcAc and BOHB by hindquarter and kidney was not impaired in thyrotoxic rats.