[Status of the rat thymus after antenatal antigenic stimulation].

Morphological reactions of the thymus to penetration of foreign antigens into the organism should be further investigated. In the work presented, morphometric, histological and histochemical methods have been applied to study specific thymic reactions of the rat fetuses to antenatal antigenic stimulation. The antigenic stimulation of the fetuses results in an increased thymic function. The changes observed in it resemble, in general, an accidental involution. A specific feature of the fetal thymic reaction is an essential enlargement of the medullary substance volume and appearance of the thymic bodies (Hassall's bodies) that demonstrates an accelerated maturation of the thymus.