Since plasma alanine concentrations are markedly elevated in late sepsis and alanine is an important gluconeogenic substrate, we investigated gluconeogenic activity in intra-abdominal sepsis. Sepsis in rats was produced by cecal ligation and puncture. After 17 to 21 hours (late sepsis, LS) livers from these and sham-operated rats were isolated and perfused at constant flow with Krebs buffer in the presence or absence of 10 mM alanine. Various phenylephrine (PE) concentrations were also used to measure gluconeogenic response to alpha-adrenergic stimulation. The results showed that glucose production from alanine by livers from LS rats was depressed in comparison to livers from sham rats (2.6 +/- 0.2 vs. 4.2 +/- 0.4 moles/gm/hr). Moreover, although livers from rats in LS responded to PE stimulation in a dose-dependent manner, the magnitude as well as the threshold of response was decreased in comparison to shams. In contrast to glucose production, VO2 of the sham and LS were not different under any conditions. Previous studies using lactate as a substrate, however, showed that both gluconeogenesis and oxidative responses were decreased in LS. Since hepatic gluconeogenic but not VO2 response was depressed with alanine, these results indicate that the decreased gluconeogenic capability precedes depressed oxidative capability in sepsis.
Adenosine Triphosphate Alanine