Effects of X-ray on lymphoid and hemopoietic tissues of albino mice.

By G. BRECHER, M.D., K. M. ENDICOTT, M.D., H. GUMP, A.B., AND H. P. BRAWNER H EINEKE,’ investigating effects of x-rays on internal organs, found the lymphoid tissues peculiarly susceptible to irradiation. This observation suggested the possibility of studying the function of the lymphoid apparatus by observing animals deprived of their lymphoid tissue by means of selective injury by x-ray.2 For this purpose it is necessary to suppress lymphopoiesis without interfering with other bodily functions of the experimental animals used. Permanent destruction of the lymphoid tissues cannot be accomplished without deleterious effects upon other organs, as shown by Hughes and Job.3 However, with a single whole body irradiation of 400 r, Henshaw4 produced in albino mice marked temporary lymphopenia accompanied by only slight neutropenia and anemia. The dosage used by Henshaw thus appeared to produce the highly selective damage of lymphoid tissues necessary for functional studies of this system. The present study was undertaken to furnish further details of the selectivity of radiation injury produced with this dosage by measuring the initial damage to all blood forming tissues and the reticulo-endothelial system, the extent and duration of the suppression of their activity, and the rate of their recovery.