Comparison of DNA contents of visceral organs in rats with ventromedial hypothalamic lesions and fed a high fat diet.

Bilateral lesions of ventromedial hypothalamus are followed by a number of changes including vagal hyperactivity and hyperinsulinemia. To investigate if cell proliferation occurs in visceral organs in rats with ventromedial hypothalamic (VMH) lesions and fed a high fat diet, we determined DNA contents of visceral organs (liver, pancreas, small and large intestines, spleen, kidney and heart) 1 and 4 week after VMH lesions or start of high fat diet. In rats with VMH lesions, DNA contents increased significantly in liver, pancreas, and small and large intestines at 1 week, and maintained the same levels until the 4th week. DNA contents increased most in the pancreas, followed by small and large intestines, and liver. DNA content did not change in spleen, kidney, or heart. In rats fed a high fat diet, there was no increase in the DNA content of these organs, except in the small intestine at 4 weeks. The results suggest that VMH lesions produce excessive DNA synthesis in visceral organs, whereas a high fat diet does not. VMH lesions may induce cell proliferation in visceral organs through vagal hyperactivity and/or changes of humoral growth factors.