[Effect of cyclosporine on the lymphoid organs of CBA mice]

The influence of cyclosporine which is an immunodepressant on morphology of the lymphoid organs was studied on CBA mice. The immunodepressant was administered intramuscularly in a single LD50 and in a dose of 7 mg/kg for the treatment course of 21 days. The examinations were performed in various periods within 28 days after discontinuation of the drug use. It was shown that cyclosporine induced cell depletion in the thymus cortical and medullar zones, inhibition of lymphocyte mitotic activity, alteration of the Hassall corpuscles and impairment of their formation. It also induced devastation of the thymus-dependent zones in the mesenteric lymph nodes and spleen. When cyclosporine was used in the course doses the morphological changes in all the lymphoid organs were more marked. The morphological changes were reversible.