Effects of cholera toxin on lymphoid system. I. Reduction of thymus cells after cholera toxin injection.

One microgram of cholera toxin was injected intravenously into DDD and AKR mice and its effects on lymphoid tissues were examined at various intervals. A remarkable reduction of thymus cells were revealed from days 1 to 11 and from days 1 to 7 in DDD and AKR mice, respectively. Only slight effects were detected on the numbers of spleen cells and peripheral blood leukocytes in both strains throughout the observation period.