Analysis of plasma middle molecular fraction in uremic patients.

Plasma ultrafiltration of patients with chronic renal failure (CRF) in terminal stage and of apparently healthy human donors were studied. It has been shown that additional chromatographic peaks observable in fractionating plasma ultrafiltrate of uremic patients are formed predominantly by substances of nonprotein nature. Aminoacid composition of middle molecular peptides' pool in qualitative respect was identical in normal humans and CRF patients. Quantitative contents of the peptides showing considerable individual fluctuations were reported.