Influence of testosterone on blood sugar, serum insulin and free fatty acid responses to glucose in normal male dog.
The influence of testosterone propionate chronic treatment on blood sugar, serum immunoreactive insulin and free fatty acid levels of male, normal, fasted, unanesthetized dogs, basally and during an intravenous glucose tolerance test has been studied. Control experiments using uninjected or vehicle-injected dogs were also performed. Blood sugar and serum immunoreactive insulin basal levels were not affected by testosterone propionate and/or its vehicle, but serum free fatty acids basal values were increased. The blood sugar curve during the test observed in the dogs in the three conditions differed little; neither glucose space nor glucose "k" value were affected by treatments. Testosterone administration reduced by 50% the serum immunoreactive insulin peak following glucose load, as compared to vehicle-injected controls. Hyperglycemia and hyperinsulinaemia induced a fall in serum free fatty acid levels in control groups, followed by a recovery period at the end of the test. Either the fall or the recovery were more intense in testosterone-treated dogs than in vehicle-injected controls. Results are discussed, emphasizing that testosterone exerts a moderate "diabetogenic" action in male dog, inasmuch as although it intensely promotes lipid mobilization and moderately reduces the insulin response to glucose, fails to induce any glucose intolerance.
D000818:Animals; D001786:Blood Glucose / Q000378:metabolism*; D003920:Diabetes Mellitus / Q000188:drug therapy / Q000378:metabolism*; D004285:Dogs; D005230:Fatty Acids, Nonesterified / Q000097:blood*; D005951:Glucose Tolerance Test; D007328:Insulin / Q000097:blood*; D008297:Male; D013739:Testosterone / Q000378:metabolism* / Q000627:therapeutic use
D001786:Blood Glucose; D005230:Fatty Acids, Nonesterified; D007328:Insulin; D013739:Testosterone