[Recovery processes in rabbit spleen after hydrocortisone administration]. / Vosstanovitel'nye protsessy v selezenke krolikov posle vvedeniia gidrokortizona.

The effect of hydrocortisone on the rabbit spleen and the recovery processes after the cessation of the hormone injection was studied. A decrease of the absorption function of RES, and spleen atrophy, expressed in a decrease of the organ weight and size followed prolonged hydrocortisons use. Most of the spleen nodes were reduced to an irregular accumulation of lymphocytes. The pyroninophilic cells disappeared in the white pulp. Cessation of the hormone effect was followed by an improvement in the general condition of the animal; the development of the spleen atrophic processes was suspended, the spleen nodes were restored with an increase of pyroninophilic cell count in them. The use of a stimulant under these conditions accelerated the recovery of the animal weight, as well as that of the atrophic spleen, with a normalization of the organ structure.

[Change in the splenic megakaryocytes of white rats during regeneration under varying conditions]. / Izmenenie megakariotsitov selezenki belykh krys pri regeneratsii v razlichnykh usloviiakh.

Different forms of megakaryocytes are found in the intact spleen of rats, with ring-like nucleus and in the form of multinuclear large cells. The division of megakaryocytes takes place by multipolar mitosis without any subsequent cytotomy. During the regeneration the megakaryocyte count and their mitotic activity displayed a sharp increase. The gravitation overload increased the megakaryocyte count and their mitotic activity even more. The use of the spleen extracts against the background of gravitation overload diminished the megakaryocyte count, but increased their mitotic activity. In hypokinetic conditions the number of megakaryocytes was sharply decreased and no mitoses were seen in these cells.

[Stimulation of post-traumatic regeneration of rat spleen under conditions of gravitational stress]. / O stimuliatsii posttravmaticheskoi regeneratsii selezenki krys v usloviiakh gravitationnoi peregruzki

Post-traumatic regeneration of the rat spleen was studied after resection of half the organ, under gravitation overloading (11 units) using spleen tissue extract prepared by Filatov's method. Gravitation overloading caused a decrease in the size of the spleen nodules, smooths their contours, increases the red pulp infiltration by the lymphocytes, reduces the number of labeled cells and the intensity of the label in the reactive centers of the spleen nodules, decelerates the capsule formation in the resection area. Application of the stimulant normalized the structure of white pulp, increased the number of labeled cells, and accelerated the capsule formation. The tissue extract used in gravitation overloading brought the restoration process nearer to the usual course of the posttraumatic spleen regeneration (by the character and periods of tissue differentiation development).