Influence of Fasting and Adrenalectomy on Normal and Malignant Lymphoid Tissue Composition.

Abstract

Summary Weight measurements and composition analyses of a transplantable lymphosarcoma and several normal lymphoid tissues in fasted, tumor-bearing CBA mice indicate that a 48-hour fast results in a marked retardation of tumor growth rate without completely inhibiting absolute growth. This tumor growth differential in fasted and fed mice is not dependent on the presence of the adrenals. On the other hand, uninvolved, non-malignant lymphoid structures in tumor-bearing animals show qualitatively the same involutional effect of fasting and the same dependence of this phenomenon on the presence of the adrenals as has been reported for tumor-free animals. Thus, malignant lymphoid cells (transplantable lymphosarcoma) in fasted mice exhibit a striking independence of the pituitary-adrenal cortical control which regulates the fasting involution of non-malignant lymphoid tissue. A considerably greater weight of the spleen was seen in fed, tumor inoculated mice, as compared to control animals. This splenic enlargement was apparent even at an early time following tumor inoculation when no tumor mass was palpable. The transplantable lymphosarcoma is relatively high in lipid content early in its development, but the percentage of lipid steadily declines as tumor size increases. Mrs. Rita Huang contributed valuable assistance with the analytical and operative procedures.