Effect of serine protease inhibitors on leukocyte interstitial migration behavior. Leukocyte interstitial migration behavior was analyzed after perivenular microinjection of PAF or CCL3 as detailed in the “Methods” section. Panels show results for directionality (A, B), velocity (C, D), and accumulated distance (E, F) of interstitially migrating leukocytes in animals treated with the serine protease inhibitors aprotinin, TXA, EACA, or vehicle (mean ± SEM for n = 4 per group).