Metabolic and pancreatic changes caused in male dogs by testosterone chronic administration

The pancreatic cytology and the glycemic, insulinemic and serum free fatty acid responses in dogs during hyperglycemia induced by glucose and over hypoglycemia evoked by insulin have been studied. The dogs were in the alternative following conditions: untreated, under propylenglycol treatment (vehicle controls) and under testosterone propionate plus its vehicle. Testosterone dose: 0.75 mg/kg body wt./day, once daily. Both intramuscular treatments lasted 2 weeks. In the pancreas of the untreated dogs, the islets presented irregular edges with acute prominences, and B-cells could be clearly appreciated, with a high content of dark brown beta-granules of insulin. B-cells presented negative images of nuclei located in the central areas of such cells. In the pancreas of the testosterone treated dogs, the yellowish cytoplasms of the B-cells looked empty, bearing just a few beta-granules (small amount of stored insulin). The B-cells appear to present a great number of vacuoles in testosterone treated dogs. The curve of glycemia in the glucose and insulin tests, the glucose space and the half-life time of insulin in circulation in dogs under testosterone plus vehicle treatment were similar to those observed in dogs treated with propylenglycol pursuant to the same experimental design used in the other two groups.(ABSTRACT TRUNCATED AT 250 WORDS)