Thrombin Inhibiting Capacity Of Normal Aorta (original) (raw)

The present investigation was designed to investigate the capacity of normal vessels to inactive activated coagulation enzymes.Fresh and frozen porcine and canine aortae were exposed in virto to thrombin, dissolved in an albumin solution. Thrombin activity appearing on the vascular wall was assayed with a chromogenic substrate (S-2238-Kabi). Aortic endothelium retained considerable amounts of thrombin. After exposure of the aorta with plasma, a rapid inactivation of thrombin was observed. Exposure of the thrombin-absorbed endothelium to a modified Ringer’s solution resulted in a much slower inactivation. A similar slow inactivation was seen after exposure with plasma devoid of anti thrombin III. No difference was observed between fresh aortae and those stored in a frozen state. No inactivation occured during the observation time when the thrombin-albumin solution was mixed with the modified Ringer’s solution without presence of aortic endothelium and when mixed with normal plasma on...