[Effect of purine derivatives on regeneration and the immunologic reactivity of animals].

The effect of azathioprine and of KI-7 (the new purine derivative) on the immunogenesis and regeneration in mammals was studied comparatively, KI-7 with a lesser toxicity than azathioprine proved to suppress the synthesis of antibodies to the SRBC in mice in case of administration of the preparation one day before or on the day of immunization; it also considerably prolonged the survival of skin allografts in rabbits in comparison with control. At the same time it was shown that under conditions of suppression of the immunogenesis system hepatic regeneration did occur in rats, but the correlation of the proliferation processes and cellular hypertrophy differed from that under ordinary restoration conditions, depending on the immunodepressor used. Thus, in difference from azathioprine, KI-7 not only inhibited the mitotic activity of the regenerating liver, but even stimulated it somewhat.

[Cytological analysis of the intact and regenerating liver of different strains of rats].

Comparative cytological studies were conducted on control and regenerating liver of two strains (August and Cotton) of rats, 2/3 of the liver was resected; 5 or 6 animals were sacrificed at each of the following postoperative periods: in 30 hours, 3, 8, 42 and 120 days. The number of binuclear cells, the size of mononuclear hepatocytes and their nuclei, the mitotic activity, and ploidity of hepatocytes were determined. The intact and regenerating liver of the August rats differed from the intact and regenerating liver of the Cotton rats by a number of cytological indices, excluding the mitotic activity.

[Cytologic features of rat liver growth in the embryonal and neonatal periods and during regeneration].

August rats were used for experiments. The growth of intact embryonal and neonatal liver was compared with the growth of adult regenerating liver at the early periods after partial hepatectomy (22, 48 and 78 hours after resection of 2/3 of the liver). Mitotic activity and the area of hepatocyte nuclei were determined; binucleated cells were counted.