Relationship between turnover rate and oxidation rate of alanine in the post-absorptive state and during parenteral nutrition before and after surgery.

Abstract

The influence of total parenteral nutrition and stomach resection on alanine turnover rate and alanine oxidation rate was measured in ten patients after single injection of U-14 C-alanine. Sequential studies were done in three patients. During parenteral nutrition alanine turnover was significantly higher than in the post-abortive state (14.75 +/- 2.56 mumol kg-1 min-1 and 8.48 +/- 1.88 mumol kg-1 min-1, respectively; P less than 0.01, mean +/- s.d.). Surgery had no additional significant influence on alanine turnover. In the post-absorptive state 4.71 +/- 0.71 mumol kg-1 min-1 was oxidized, during parenteral feeding before surgery 7.93 +/- 1.93 mumol kg-1 min-1 (P less than 0.01 v. post-absorptive state), and during parenteral feeding after surgery 7.67 +/- 1.67 mumol kg-1 min-1. The percentages of alanine turnover used for oxidation in the post-absorptive state and during parenteral feeding before and after surgery were 57 +/- 11%, 54 +/- 7% and 45 +/- 11%, respectively (no significant differences). It is concluded that the degree of alanine oxidation seems to be directed by the degree of alanine turnover. A discussion about differences in alanine oxidation under different circumstances must therefore include a discussion about changes in alanine turnover.