The role of the lymphoid organs in antibody production

Summary

Simultaneous removal of the thymus gland and spleen in rabbits does not affect the viability of these animals. Together with the other organs the thymus gland and the spleentake part in the response of the animal to the administration of the typhoid antigen. This participation is manifested in various forms: thymectomy promotes greater accumulation of the antibodies in the blood; splenectomy on the contrary reduces the titre: Simultaneous removal of the thymus and spleen results in a greater accumulation of antibodies than in the case of splenectomized animals, although it is slightly less than in the normal ones.

Thus one may assume that the thymus has a depressing effect on the mechanisms responsible for the accumulation of the antibodies in the blood; this effect is especially clearly manifested in the absence of the spleen. This is also confirmed experimentally by the increased titer of circulating antibodies in splenectomized rabbits after thymectomy, as well as by experiments with administration of thymus homogenate. The depressive effect of the thymus gland is manifested only during the first 48 hours after the administration of the antigen.