Despite the modern surgery progress and success, the achievements of asepsis and antisepsis, as well as rather broad possibilities of antibacterial, infusion and detoxification therapy, the incidence of peritonitis and mortality from it remain at a high level.The aim of the study was to clarify the significance of the activity of Kupffer cells in the regulation of total cholesterol in the liver and blood lipoproteins, the level of iodine-containing thyroid hormones in the blood and the body temperature in rats with experimental peritonitis.It was found that in the conditions of experimental peritonitis in rats, secondary atherogenic dyslipoproteinemia develops and the level of iodine-containing thyroid hormones in the blood decreases. Kupffer cells and nitrogen monoxide are involved in the changes in the content of total cholesterol, lipoproteins, the level of iodine-containing hormones in the blood plasma and the body temperature during peritonitis. A decrease in the activity of Kupffer cells in peritonitis, apparently, plays a compensatory role and prevents the development of secondary dyslipoproteinemia.