Extrahypothalamic mediation of changes in feeding behavior induced by growth of Walker 256 carcinosarcoma in rats.

Feeding efficiency (amount of food ingested per unit of feeding activity) was chronically depressed in male Sprague-Dawley rats recovered from the acute aphagia or hypophagia of lateral hypothalamic damage. The extent of depression varied with the severity of the acute feeding response to hypothalamic damage. Growth of Walker 256 carcinosarcoma in intact rats increased feeding efficiency. Chronic lateral hypothalamic damage did not significantly attenuate tumor-induced increase in feeding efficiency but lowered the initial and maximum efficiency levels. Growth of the tumor-bearing host was depressed by residual lateral hypothalamic damage, but this depression was not related to the severity of the acute feeding response to damage.