Effect of glucose infusion in dogs on blood sugar, insulinemia and serum free fatty acid responses.

A glucose dose-response study, in normal dogs, was performed in vivo. Glucose doses: a) priming 700 mg/kg body wt, i.v.; b) intravenous infusions: 20 (Group I), 28 (Group II), 44 (Group III) and 100 mg/kg body wt/min (Group IV) for 60 min. The following responses were studied: blood sugar, serum immunoreactive insulin and serum free fatty acids. There were significant effects of the dose of infused glucose on blood sugar and serum insulin integrated responses; the integrated serum free fatty acid response was not influenced. Mean integrated blood sugar responses in groups I, II and III coincided, while that observed in Group IV was increased. Mean integrated serum insulin response in group III was above those found in I, II and IV; the response in II was below the one detected in IV. In groups I and II, there was a linear inverse relationship of blood sugar to serum insulin integrated responses; this relationship vanished as data from groups III and IV were also included in the calculation of respective product-moment correlation coefficient. There was a significant effect of the dose of infused glucose on the insulinogenic index during glucose test. Mean insulinogenic indices in groups II and IV were below that of group III. A small unique peak of insulin response in group I during glucose infusion test was observed. A typical biphasic insulin response in systemic venous blood of animals of group II, was found.(ABSTRACT TRUNCATED AT 250 WORDS)