Effect of cyclophosphamide on spleen lymphocytes in mice.

The experiments were carried out in the following groups of Swiss mice: 1. after administration of a single dose of cyclophosphamide (300 mg/kg); 2. after i.v. injection of sheep red blood cells (4 X 10(8)); 3. injected with SRBC on the 4th day after cyclophosphamide administration; 4. control group. In all mice, histologic evaluation of the spleen and determination of the percentage of Fc and C3 lymphocytes (EA and EAC rosettes) were performed on the days following cyclophosphamide administration. The results obtained revealed that cyclophosphamide caused fast elimination of lymphocytes from the spleen lymphoid tissue in thymus-dependent areas, most strongly pronounced on the 4th day after cyclophosphamide administration. Simultaneous injection of sheep red blood cells evoked changes in the spleen, typical of immune response. These changes, in respect to all parameters, were less pronounced in animals treated with antigen only.