A uremic peptide containing polyamine: formation and possible role in uremic hypertriglyceridemia.

Concentrations of peptidic compounds in blood plasma of uremics are increased. Evidence for participation of intestinal bacteria in the production of such peptides (presumably toxic) was obtained by isolation of a strongly basic peptide containing covalently bound spermidine from peritoneal dialysate of patients with chronic uremia. The same peptide was found in blood plasma of patients with end-stage chronic renal failure. The absence of glutamic acid in the spermidinepeptide molecule suggests that an enzyme different from the transglutaminase of mammalian cells must take part in the synthesis of spermidinepeptide. This conjugate forms a relatively stable complex with insulin, thus altering the action of the hormone on adipose cell metabolism. Also, interaction of spermidinepeptide with insulin and lipoproteins may contribute to hypertriglyceridemia and accelerated atherosclerosis in patients with chronic uremia.