Impaired Blood Clearance of Bacteria and Phagocytic Activity in Vitamin A-Deficient Rats

Abstract
The effect of vitamin A deficiency on the functional integrity of the reticuloendothelial system and the phagocytic capacity of circulating polymorphonuclear leukocytes [PMN] was evaluated in retinoate-cycled vitamin A-deficient rats under conditions such that secondary dietary imbalances were eliminated. Kinetics of blood clearance of 2 x 107 Escherichia coli injected i.v. was depressed within 8 days of the withdrawal of retinoic acid; all animals were profoundly affected by Day 12 of deficiency. In vitro, the phagocytic activity of PMN was similarly affected; by Day 12 of deficiency, phagocytic capacity in all deficient animals was < 40% of the appropriate control values (P < 0.01). Animals rendered vitamin A deficient by this procedure also displayed marked susceptibility to endogenous bacterial infection, as judged from the proportion of deficient rats that spontaneously developed bacteremia during the later stages of deficiency. Reticuloendothelial leukocytic and PMN functions are impaired in vitamin A deficiency in the absence of other dietary imbalances.