Topographical Distribution of Plasma Cells in Lymphoid Organs of Young Mature Albino Rats

Abstract

Following a previous paper which studied the percentage of plasma cells in smear preparations of various lymphoid organs in young adult albino rats, the distribution of the plasma cells in different regions of lymphoid organs was investigated in tissue sections. The main site of distribution of the plasma cells was the medullary cord of the lymph nodes, the red pulp of the spleen, the internodular region in the subserosa in PEYER's patches and the borderline region between the cortex and medulla of the thymus. The percentage of the plasma cells were found to be 32.52-48.18% in the medullary cord, 1.98% in the splenic red pulp, 4.62% in the internodular region of the PEYER's patches, and 1.04% in the medulla of the thymus.
The plasma cells frequently formed cells nests of varying sizes in the medullary cord of the lymph nodes, BILLROTH's cords of the spleen and internodular region of the PEYER's patches, some mitotic figures to be identified with the plasma cell being found therein. Such findings indicate that the above-mentioned regions may be the sites of active proliferation of the plasma cells.