Influence of homeorhetic state on ruminant metabolism and substrate selection for hepatic gluconeogenesis.

摘要

We hypothesized that the contribution of amino acids to hepatic gluconeogenesis would increase when glucose demand was increased in ruminants. Our first approach was to establish a sheep model for increased glucose demand. Four wethers injected with excipient or.5, 1.0, or 2.0 g/d of phlorizin excreted an average of 0,72.7, 97.9, and 98.5 g/d of glucose into the urine. Wethers injected with 1.0 g/d of phlorizin excreted approximately 50% of their probable daily glucose production into their urine and adapted by 24 h after the first injection. Phlorizin-induced changes in plasma variables suggested increased gluconeogenesis from amino acids. In experiment 2, isolated hepatocytes from 10 Dorset wethers injected with excipient or 1.0 g/d of phlorizin for 72 h were used to determine the effects of increased glucose demand on conversion of (1-