Effect of Various Treatment Modes of Experimental Mammary Gland Tumor on Structure of Anterior Mediastinal Lymph Nodes

The effects of various treatment modes on the morphology of anterior mediastinal lymph nodes were examined in female Wistar rats with chemically provoked breast cancer. Adjuvant chemotherapy impaired filtration barrier potential of the anterior mediastinal lymph nodes, which manifested in increased volume of sinuses, reduced volumes of lymphoid nodules with germinal centers and thymus-dependent regions, down-regulated proliferative activity of lymphoid cells in B-cell zone and paracortex, and diminished macrophage score in all zones. Intraperitoneal injection of double-stranded DNA preparation (5 mg/kg) activated the humoral and cellular immune responses manifested by morphological alterations in anterior mediastinal lymph nodes observed in parallel with a decrease of medullary sinuses volume: enhancement of lymphocyte volume and lymphocyte score in paracortex, mantle zone expansion, and an increase of volume of the light centers in lymphoid nodules paralleled with diminished proliferative activity in them.