Abstract: | Changes in the number of spleen exo-colonies and post-radiation repopulation of hematopoietic organs were studied in recipients upon injection of bone marrow treated with anti-brain serum (ABS) with and without thymocytes on days 9-14. It was shown that on days 9-11 colony formation in mice injected bone marrow treated with ABS was much lower than the control level. However, by day 14 the number of colonies increased drastically as compared to the control. Thymocyte supplementation normalized colony formation at any time of observation. Similar pattern is noted in post-radiation repopulation of spleen and bone marrow of mice injected bone marrow pretreated with ABS with or without thymocytes. It is assumed that ABS inactivates bone marrow cells participating in the regulation of CFUs proliferation. |