Effect of malnutrition on susceptibility of mice to Trypanosoma musculi: Vitamin A-deficiency

Summary Vitamin A-deficiency was studied in mice infected with Trypanosoma musculi.Irrespective of diet, trypomastigotes (trypanosomes) appeared in peripheral tail blood of all inoculated mice after 6-day incubation periods. On the average, vitamin A-deficient mice had parasitemias about 10 times greater than animals fed a complete diet and 8 times pair-fed controls. Parasitemias lasted longer in vitamin-deficient hosts, and reached a maximum five days later than those from control hosts.The action of the antibody which inhibits reproduction of the trypomastigotes was delayed five days in vitamin-deficient mice; in pair-fed animals ablastic action occurred slightly earlier than in normal control animals. The action of the terminal lytic antibody was delayed by 6 days in metabolically deficient mice than in normal controls and by 4 days in pair-fed controls.Body weight gains in mice on complete, vitamin A-deficient or pair-fed control diets and given living cells or homogenate of T. musculi showed significant increases over uninoculated controls. Irrespective of dietary group, animals receiving living cells or homogenate of T. musculi ate more food than the control animals beginning 10 days after inoculation. Regardless of diet, no differences in weight gain or food consumption were seen in animals inoculated with physiological saline or metabolic products of T. musculi when compared with uninoculated controls.Key to Lettering of Figs. 1–3 N Averages for uninoculated mice. - L Averages for mice inoculated with living cells of T. musculi. - H Averages for mice inoculated with homogenate of T. musculi. - M Averages for mice inoculated with metabolic products of T. musculi. - P Averages for mice inoculated with physiological saline.