The effect of renal cytomedin on coagulative and microcirculatory hemostasis and lipid peroxidation was studied in 30 Wistar rats with induced Heymann's nephritis. The course of nephritis caused activation of lipid peroxidation, development of the syndrome of disseminated intravascular coagulation of blood in the animals, and diminution of antiaggregation properties of the kidney. Administration of the polypeptide normalized these processes. Thus, the discussed cytomedin produces a marked positive regulatory effect in experimental renal pathology.