Determination of overall insulin sensitivity in diabetic mice, KK

A convenient methods for determining the overall insulin sensitivity of small animals was established based on the steady state plasma glucose (SSPG) concentration methods of Shen, Reaven and Farguhar (1970). Subcutaneous injection into C57BL/6 mice of saline containing epinephrine, propranolol, glucose and (3H-3)glucose with or without insulin gave steady state levels of blood glucose (SSBG), plasma insulin (SSPI) and specific activity of blood glucose (SSBG), plasma insulin (SSPI) and specific activity of blood glucose after 45 minutes. Glucose turnover (GTN) and hepatic glucose output (HGO) were computed using specific activity of blood glucose and the influx rate of injected glucose. The method was applied to diabetic and insulin resistant mice, KK. There was no difference in GTN and HGO between KK and C57BL/6 mice regardless of whether insulin was injected or not. SSPI of both strains increased in the same injected or not, SSPI of both strains increased in the same injected or not. SSPI of both strains increased in the same fashion in response to increasing doses of the hormone. SSBG of both strains fell in response to increasing SSPI level, but the response of SSBG was less prominent in KK mice. Consequently, the insulin dose-response curve of SSBG apparently shifted rightwards in KK mice.