[The effect of the local irradiation of areas of the thymus, hypothalamus/hypophysis and gonads in mice on the cellularity of the autologous and transplanted thymus].

Mice were grafted with syngeneic neonatal thymus 1-3 days or 7.5-8 months after local irradiation of thymus, hypothalamus/hypophysis and gonads. Thymus weight and thymocyte number were measured in autologous and grafted thymus 35-40 days after the transplantation. Thymus transplantation induces significant decrease in weight and cellularity of both autologous and grafted thymus. Irradiation of autologous and grafted thymus in doses of 1 and 10 Gy abrogates this effect. Irradiation of hypothalamus/hypophysis and gonads induces decrease of weight and cellularity of autologous and grafted thymus. Irradiation of gonads does not abrogate inhibitory effect of thymus transplantation. Local irradiation of all three regions decreases titre of serum thymic activity and influence concentrations of some hypophysis and adrenal hormones.