Effect of protein ingestion on splanchnic and leg metabolism in normal man and in patients with diabetes mellitus

Abstract

The inter organ flux of substrates after a protein rich meal was studied in 7 healthy subjects and in 8 patients with diabetes mellitus. Arterial concentrations as well as leg and splanchnic exchange of amino acids, carbohydrate substrates, free fatty acids (FFA), and ketone bodies were examined in the basal state and for 3 hr after the ingestion of lean beef (3 g/kg body wt). Insulin was withheld for 24 hr before the study in the diabetic patients. It is concluded that repletion of muscle nitrogen occurs after protein ingestion by selective splanchnic escape and muscle uptake of branched chain amino acids despite ongoing peripheral release of alanine and glutamine; in patients with diabetes mellitus, leg uptake of total amino acids is normal or transiently increased; however, uptake of branched chain amino acids is less persistent and augmented arterial increments of these amino acids are observed; protein intake has a stimulatory effect on splanchnic glucose output in diabetes which is not observed in normal man.