INHIBITORY EFFECT OF HYPOTHALAMIC-LESIONS ON LIVER TUMOR INDUCTION BY N-2-FLUORENYLACETAMIDE IN MALE RATS

Abstract

Bilateral electrolytic lesions were placed in the median eminence area of the hypothalamus in 12-wk-old male Wistar rats. Sham-operated and untreated control rats were also included. Two weeks later, 1/2 of them were given 0.03% N-2-fluorenylacetamide incorporated into the diet for 16 wk with adequate resting periods in between. The animals were killed 34 wk after the last carcinogen feeding. Lesions in the hypothalamus effectively inhibited liver tumor formation (0 of 16, 0%). The incidence of hepatocellular carcinomas in sham-operated rats was 38.5% (5 of 13), and that of untreated controls was 42.9% (6 of 14). No tumors developed in rats fed a diet without carcinogen. Testicular atrophy, inactive thyroid glands and shorter nasoanal lengths were observed in rats with lesions in the hypothalamus irrespective of carcinogen treatment. Lesions in the median eminence area of the hypothalamus inhibit the induction of liver carcinogenesis with N-2-fluorenylacetamide in male rats.