Effect of Hypophysectomy on Pathologic Changes in Rats Force-fed a Threonine-devoid Diet

Abstract
This study was conducted to determine whether the morphologic and biochemical changes previously observed in intact rats force-fed a purified diet devoid of threonine could have been influenced by hypophyseal hormones, particularly growth hormone. Young hypophysectomized rats with or without low doses of cortisone acetate were force-fed a purified diet devoid of threonine for 1 or 2 days. These animals developed an enlarged fatty liver with a periportal distribution of lipid and an increase in hepatic glycogen, and atrophy of the pancreas, stomach and spleen. The animals force-fed the threonine-devoid diet showed increased incorporation of 14C-leucine into hepatic protein with decreased incorporation into gastrocnemius and splenic proteins in comparison with control animals force-fed a complete diet. These changes were similar to those reported earlier in similar experiments with normal rats. Although some of the hepatic changes in rats force-fed the threonine-free diet are similar to those obtained in normal or hypophysectomized rats treated with growth hormone, the present results indicate that the pathologic changes found in animals with threonine deficiency are not due to increased pituitary gland secretion.