Food and water intakes and Walker tumor growth in rats with hypothalamic lesions

Abstract

By the 15th day post transplant of the Walker tumor into Sprague-Dawley rats, food intake showed a depression which continued with subsequent tumor growth. A less severe depression of water intake occurred later, indicating dissociation of food and water intake in the tumor bearer. Electrolytic lesions in the lateral area of the hypothalamus of animals at 15 days post transplant produced true aphagia and adipsia; thus the controlling mechanism of the lateral area is functional in the tumor bearer at 15 days. Tumor bearers with sham operations in the lateral area at 15 days showed an initial depression in food and water intakes. Food intake eventually equaled that of nonoperated tumor bearers, but water intake remained depressed, again indicating dissociation of food and water intakes. The Walker tumor was transplanted into rats previously made hyperphagic by lesions in the ventromedial hypothalamus. Food intake began to decline by 15 days, eventually reaching very low levels; thus depression of food intake in the intact tumor-bearing host is not mediated via the ventromedial hypothalamus.