[Structural and functional changes in the spleen in experimental proteins and energy deficiency]

The authors studied the immature reaction of 60 adult female Wistar rats fed diets of varying protein content. Within 16 weeks, the diet very low in protein (daily intake of 1.22 g of protein as compared to 3.75 g of protein in the control animals) led to atrophy and fibrosis in the spleen, a morphological correlate to suppressed humoral immunity. A pathologically increased autophagy was demonstrated by electron microscopy that surpassed the functional capacity of the lysosomes of the immunocompetent cells. In case of medium-protein diet (daily intake 2.55 g of protein), the structural and functional status of the protein-synthetizing apparatus and of the lysosomes secured the normal blast transformation of the lymphocytes in the splenic capsules and an effective immune reaction. However, a boundary between the adaptation reparative and the alterative irreversible pathological processes in the lymphatic organs became delineated when the medium-protein diet was given.