Plasma amino acid, glucagon, and insulin concentrations in dogs with nitrosamine-induced hepatic disease

Abstract

Plasma amino acids, glucagon, and insulin concentrations were determined once a week in dogs that developed acute hepatic necrosis and chronic hepatic insufficiency after treatment with dimethylnitrosamine. During the acute phase, plasma concentrations of most amino acids increased, with the changes usually correlating with increased glucagon values. Insulin correlated with changes in 10 of 21 amino acids, but the latter were not the most abundant nor the branched-chain amino acids. During the chronic phase, plasma phenylalanine tyrosine, and methionine concentrations remained increased throughout the study. Plasma values of these amino acids did not correlate with plasma concentrations of either glucagon or insulin. The values of the most abundant amino acids were less than base-line levels during the chronic phase, and 9 of 10 of these correlated positively with glucagon concentrations, but not insulin. Only proline correlated positively with insulin. Isoleucine and valine showed a negative correlation with insulin. The low concentrations of the nonaromatic amino acids increased during the time from the early to late chronic phase, during which time plasma glucagon increased and insulin remained unchanged. This study shows that a significant positive correlation existed between glucagon and the most abundant plasma amino acids during the chronic phase of hepatic insufficiency, at which time most plasma amino acid concentrations were returning toward base line. Increased glucagon values did not correlate with any evidence for deterioration of hepatic function.