Ampicillin effect on lymphatic tissue of mice and its reaction to sheep erythrocytes.

Ampicillin given to B6A F1 mice in multiple doses of 250 mg/kg of body weight caused changes of the thymus with reduction in size, weight and cellularity of the organ, and with a decrease of the migratory activity in vitro of thymocytes derived from mice treated with ampicillin. Ampicillin produced also a stimulatory influence on the reaction of B-lymphocyte zone in the subpopliteal lymph nodes of mice stimulated with sheep erythrocytes, and delayed the development of this reaction in the thymus-dependent zone of these nodes in response to syngeneic erythrocytes.