FIGURE 5.

Inhibition of extrinsic tenase activity by b-Lac under flow conditions. PCPS-coated capillaries containing preassembled extrinsic tenase were perfused with a solution containing hfX (170 nm) at a shear rate of 100 s⁻¹ for ∼780 s to establish an initial steady-state level of hfXa generation after which the perfusate was switched to one containing hfX (170 nm) and b-Lac (25–200 nm) for an additional ∼780 s. A, the percentage of hfXa activity in the effluent after perfusion with the b-Lac-containing solution is shown relative to the initial steady-state level of hfXa as a function of b-Lac concentration (n = 2). B, the average of two experiments with 200 nm b-Lac in the perfusate is shown. The solid black line shows hfXa generation with the primary perfusate containing only hfX, whereas the dotted line shows hfXa generation after the introduction of 200 nm b-Lac to the perfusate (as indicated by the arrow). The thin dotted line shows the fit of Equation 1 to the primary perfusate data. Error bars, S.D.