Diet-induced reduction in serum lipoproteins stimulates cell proliferation in weanling rats

Male weanling Wistar rats were fed a 4% cholestyramine diet and used as a model to demonstrate that a reduction in serum low density lipoproteins stimulates de novo cholesterogenesis leading to DNA synthesis and cell proliferation. Feeding this diet resulted in a decrease in serum very low density lipoproteins and low density lipoproteins, an increase in high density lipoproteins and an increase in de novo cholesterogenesis in liver, thymus, spleen, pancreas, kidney and lung. DNA synthesis increased only in the thymus and spleen. Histological examination of spleen, thymus and lymph nodes showed an increased number of immature cells and enhanced mitotic activity. These results suggest that a marked reduction in serum low density lipoproteins stimulates de novo cholesterogenesis, leading to enhanced DNA synthesis and cell proliferation.