Abstract
Renal glucose production and utilization rates and total body glucose turnover rate in intact unanesthetized control sheep and acidotic sheep induced by HCI infusion were determined by the measurements of renal blood flow and arteriovenous 14C-glucose concentration differences using the method of primed continuous infusion of U-14C-glucose. At the same time renal ammonia production rate was measured, and the relationship between renal glucose production and ammonia production during acidosis was quantitatively estimated. No significant difference in the renal blood flow existed between the groups. Acidosis extremely stimulated renal glucose production (2-fold) and utilization (2.5-fold) and renal ammonia production (9-fold), but not renal glucose production, which was measured by the method of arteriovenous glucose difference, and total body glucose turnover rate. Furthermore, acidosis caused a 25% inhibition of hepatic glucose production. This finding may suggest that the pattern of glucose metabolism in sheep liver and kidney to acid-base status was very different. On the assumption that all of ammonia produced by kidney originate from only glutamine and all of glutamine residue, which is deaminated and deamided via the glutaminase pathway, is converted to glucose, in control sheep glucose converted from glutamine was only 0.8% of glucose produced by kidney and in acidosis it was 4.2%. Thus, it appears that there is relationship between increased renal glucose production and ammonia production in acidosis. It is concluded, however, that renal gluconeogenesis and ammonia production in sheep may not be interdependent, since the contribution of glutamine to renal gluconeogenesis is very small.
