The Effect of Some Physiological Stimuli on Fibrinolytic Activity in Man Measured by the Heparin Fractionation Method.

The recently reported heparin fractionation method for measuring fibrinolytic activity in plasma (Green, 1959; Green and Thomson, 1962) has been used to re-examine the effect of certain physiological stimuli on fibrinolytic activity in man. In addition to providing further data on factors influencing natural fibrinolytic activity such a study afforded a means of assessing the value and sensitivity of the heparin fractionation method in the investigation of fibrinoylsis. For this reason dilute whole blood lysis times (Fearnley, Balmforth, and Fearnley, 1957) were measured on most samples to act as a reference for the heparin fraction lysis times. The fibrinolytic activity of blood may be altered generally or the change may be confined to a localized part of the circulation. General and local changes in fibrinolytic activity will be considered separately below.