[The biological activity of chalone-like proteoglycans isolated from the spleen and thymus at various periods of ontogeny]. / Biologicheskaia aktivnost' keilonopodobnykh proteoglikanov, vydelennykh iz selezenki i timusa v raznye periody ontogeneza.

Chalone-like proteoglycans from sheep and bovine thymus and spleen were shown to suppress cell proliferation in murine thymus or spleen. Their effect appeared to be organ-specific but not species-specific. Administration of the proteoglycans resulted in a decrease in the mitotic activity of thymus and spleen cells 24h (strain C57BL), three days (hybrids), four days (nude mice) or five days (highly cancerous strain C3H/He and white mongrel mice) after birth. These changes are probably due to genetic peculiarities of immune system formation in different mouse strains. The activity of chalone-like proteoglycans from spleen and thymus of 1-, 3- and 6-months old sheep was lower than that of adult sheep (two and five years old) indicating that the proteoglycan activity increases during ontogenesis.

[The activity of growth-regulating substances isolated from the spleen and thymus of healthy cows and of those with hemoblastoses]. / Issledovanie aktivnosti rostreguliruiushchikh veshchestv, vydelennykh iz selezenki i timusa zdorovykh i bol'nykh gemoblastozami korov.

Certain agents of the proteoglycan nature possessing organ-specific rather than the species-specific antimitotic chalone activity have been obtained from the normal bovine spleen and thymus. The preparations obtained by the same method from the spleen and the thymus of animals affected by lympholeukemia and lymphosarcoma did not reveal the antimitotic activity; moreover, they were of high mitogenic organ-specific character. A connection between the mitogenic factor produced by lymphocytic cells and the bovine leukemia virus is possible.