“Medium molecules” as nonspecific regulators of phagocytic activity

Three identical oligopeptide-containing fractions of so-called “medium molecules”, isolated by sequential ultrafiltration and gel chromatography from the blood of 8 intact dogs and 15 dogs with an extensive thermal burn, were examined for their impact on phagocytic cells (neutrophil granulocytes and macrophages) in relation to the molecular-weight distribution of the molecules. The relatively high-polymer fractions of medium molecules, unlike oligomeric fractions, stimulated the phagocytic activity of these cells. Because of their increased polymerism, the fractions of medium molecules from dogs with thermal trauma stimulated phagocytosis to a greater extent than did those from intact animals. Translatedfrom Byulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 2, pp. 159–162, February, 1995 Presented by V. A. Trufakin, Member of the Russian Academy of Medical Sciences