Studies on the Plasma Cells in the Lymphoid Organ during Pregnancy and Lactation in the Mouse I. Observations in the Thymus

The following experiment was performed to study on the numerical changes of the IgG, IgM and IgA bearing cells in the thymus during pregnancy and lactation in the mouse. The experimental animals were mated allogeneically (female ICRC x male DDY), and the thymi were resected at 4, 6 and 19 days of gestation and postpartum 20 days. The thymi were stained with MGP and immunohistochemical reaction. Then each group was compared with the virgin control group. The following results were obtained: 1. In 6 days of gestation, the number of IgA bearing cells was significantly more than that in virgin. 2. In 19 days of gestation, the number of IgG. IgM and IgA bearing cells was significantly more than that in virgin. 3. In suckling group, the number of IgG and IgA bearing cells was significantly more than that in virgin. 4. The immunoglobulin bearing cells were localized in perivascular region. On the basis of the above results, it is suggested that the thymus. the primary lymphoid organ, has relation with the maternal immune response, too