No abstract

The role of hypercholesterolemia as a factor modulating functional activity of macrophages during the growth of syngeneic transplanted 22a hepatoma in mice was studied. Starting from day 21 after inoculation of tumor cells we observed the development of hyperlipoproteinemia paralleled by an increase in macrophage activity parameters. The total serum cholesterol content and production of nitroxide anions by macrophages were in positive correlation on days 14-35 of tumor growth. We hypothesized that the development of hypercholesterolemia at the late stages of some tumor growth is a factor stimulating production of nitrites and 5'-nucleotidase activity.

Intensive apoptotic death of thymocytes is a possible mechanism of thymus involution during tumor growth. We studied the role of hypercholesterolemia and lactate acidosis in the induction of increased sensitivity of thymocytes to apoptosis during growth of transplanted hepatoma 22a in mice. Spontaneous apoptosis in thymocytes during tumor growth in mice was studied in vitro by acridine orange/ethidium bromide staining and diphenylamine test. Plasma levels of lactate, total cholesterol, alpha-cholesterol, and triglycerides were measured. A positive correlation was found between intensification of apoptosis (diphenylamine test) and increased concentration of total plasma cholesterol on days 21 and 28 after inoculation of tumor cells. Plasma lactate content did not increase at this term. We hypothesize that hypercholesterolemia accompanying tumor growth acts as a factor increasing thymocyte sensitivity to apoptosis.