[A low-molecular polypeptide of the blood serum in warm-blooded animals: its effect on cell adhesion and proliferation].

The review deals with investigation of a 6-kDa polypeptide discovered in blood whey of warm-blooded animals. This polypeptide stimulates cell adhesion, the action being characterized by absence of tissue and species specificity. Dose dependence of biological effect, intensively is revealed: optimal are concentrations of 10(-15)--10(-19)m, at which the polypeptide stimulates in-culture fibroblast proliferation. Information is provided about biochemical investigation of the polypeptide: method of its extraction from the whey and of purification; physicochemical properties of the polypeptide extracted from blood whey of various animals and man. For one of the cattle, amino acid composition is determined. Polypeptide states in blood whey at different ontogenetic stages are studied. At earlier stages, the polypeptide is "active"; at later stages of prenatal and in postnatal development, it is "nonactive" due to its being bound by another whey substance, a "carrier". By sum of results of investigation of its physicochemical properties and biological activity, the polypeptide represents previously unstudied blood whey factor.