UHRA does not promote lysis of plasma clots. The influence of UHRA or protamine on human plasma clot lysis was investigated using turbidimetry, as described in “Methods.” (A) Turbidity curves (A405nm) showing lag time, clot formation, and lysis phases; error bars were omitted for clarity. TF and CaCl2 (20 mM) initiated clot formation. Clot lysis was enhanced by adding exogenous tissue plasminogen activator at the initiation of clot formation. Absorbance measured at 2-minute intervals is used for calculating the lag time. The absorbance measured at 8-minute intervals is shown. (B-C) CLT50 and area under the curve values in the presence of UHRA or protamine. Relative to the polycation-free control, clots formed in the presence of UHRA show no significant change in CLT50 and area under the curve values, indicating they are stable and have a normal degradation profile. CLT50 values were reduced significantly (*P < .035) in the presence of 50 and 100 µg/mL protamine, respectively, suggesting faster lysis of these clots compared with the polycation-free control. Results are expressed as the mean ± SE of 6 measurements from 2 independent experiments. Unpaired 2-tailed t tests were performed to determine the significance.
