| 摘要 |
<p>Pharmaceutically active fractions (F) consist of components of mol. wt. 10,000 and when filtered through a column of the reticulated polydextran gel 'Sephadex G75' (RTM) of bead size 40-120 mu dia. which permits fractionation of mixts. of mol. wt. 5000-50,000, gives an active eluate at between 4 and 5 dead vol. When filtered through a column of the polyacrylamide gel 'Bio-Gel P2' (RTM) as 37-74 mu beads, having exclusion limit 1800 and able to fractionate cpds. of mol. wt. 100-1800, the major part of the activity is eluted between 2.5, and 4 dead vol. The fractions inhibit in vivo and in vitro incorporation of 3H-thymidine into DNA by lymphocytes, and have immunosuppressive props., i.e. they antagonise stimulating effects of mitogens on lymphocytes; reduce delayed hypersensitivity to sheep erythrocytes or dinitrochlorobenzene and, in the Jerne-Nordin method, reduce number of plaques induced by the lymphocytes of animals already treated with (F) in a culture of spleen cells in presence of sheep erythrocytes. The degree of purity is higher than that of known, similar fractions.</p> |
