cit-title-group
Abstract
A wide range of studies has been done to examine the effect of nutritional restriction on the function of various components of the immune system (for reviews see 1, 2). However, few investigators have studied the effect of a protein restriction on macrophage phagocytic activity. Gautam et al. (3) and Passwell et al. (4) have both reported a decreased clearance of colloidal carbon in vivo in mice fed a protein-restricted diet for 3 weeks (4) or 6 weeks (3). In addition, Gautam et al. (3) observed a decreased clearance of 51Cr-labeled sheep red blood cells (SRBC). Others have reported a de creased clearance of 32P-labeled Escherichia colt in monkeys fed a protein-deficient diet (5). On the other hand, Cooper et al. (6) found an increase in the in vitro phagocytosis of bacteria by peritoneal macrophages from animals fed an 8% protein diet. Keusch et al. reported no difference in the percentage of monocytes that react with IgG-coated SRBC (7). Thus the literature contains contradictory data concerning the effect of experimental protein restriction on macrophage function. The macrophage is an integral component of the immune system and intimately involved in a variety of immune functions in addition to phagocytosis