Studies on thymus products. II. Demonstration and characterization of a circulating thymic hormone.

摘要: Normal mouse serum confers on bone marrow rosette-forming cells (RFC) from normal mice a high sensitivity to anti-theta (AθS) and azathioprine (AZ) which they otherwise lack. Such an effect can also be demonstrated spleen adult thymectomized mice, `thymus-deprived' nude but the amount of required is higher in latter mice. This activity RFC disappears after thymectomy donor with half-life 2.5 hours reappears within 4 days grafting thymus. Serum thymic (TA) present different amounts strains ageing it progressively disappears. No TA found 4-week-old stable lyophilization thermolabile solution. It passes through UM 10 Amicon membranes, suggests that its molecular weight (mol. wt) probably < 10,000. reversibly suppressed presence inhibitor mol. wt between 100,000 300,000. not detectable unless incubated containing for 60 minutes at 37°. The biological significance still matter speculation role maturation or expansion T-cells suspected.