Elevation of plasma antithrombin in the aging arteriosclerotic subject

¹ Arteriosclerosis Research Laboratory, St. Barnabas Hospital Research Foundation, and Department of Physiology, University of Minnesota School of Medicine, Minneapolis, Minnesota

Plasma samples from aging human subjects who had recovered from the trauma of a myocardial infarct and who were not on anticoagulant therapy were assayed for antithrombin activity. Antithrombin was assayed by methods which measure the ability of plasma to destroy an excess of thrombin, human or bovine in origin. Residual thrombin was quantitated either by clotting time or by hydrolysis of TAME (p-toluene sulfonyl-l-arginine methyl ester-HCl). All methods showed unequivocally that plasma antithrombin increases up to 33% (P < 0.002) in subjects who have fully recovered from a thrombotic episode.