Cerebrospinal fluid (CSF) fibrinopeptide A (FPA) levels were measured serially by radioimmunoassay (RIA) in 25 patients with subarachnoid hemorrhage (SAH). The FPA levels, which reflect the amount of thrombin, were extremely high on days 0 to 1 (1, 012±334 ng/ml, mean±SE) and decreased rapidly. Bradykinin (BK) levels in the CSF of 27 patients with SAH, which were also measured serially by RIA, were 122.7±22.7 pg/ml on day 0, 38.6±6.9 pg/ml on day 1, and 22.7±6.3 pg/ml on day 2, and decreased slowly. Thromboxane B
2 (TXB
2), which is produced by the activation of platelets, was measured by RIA in the CSF of 25 patients with SAH. TXB
2 levels were 771±280 pg/ml on days 0 to 1, 169±30.9 pg/ml on days 2 through 4, 259±45.2 pg/ml on days 5 through 7, and 167±12.9 pg/ml on days 8 through 14. The control values of FPA, BK, and TXB
2 were 1.2±0.9 ng/ml, 8.0±3.3 pg/ml, and 93.0±14.6 pg/ml (mean±SD), respectively. BK is produced through the activation of Hageman factor, which is believed to be activated by trabeculae arranged in collagen bundles in the subarachnoid space. In the case of SAH, the coagulation process might be initiated by Hageman factor (intrinsic system). Platelets are also thought to be activated by trabeculae, as well as by thrombin. Trabeculae can thus be assumed to play a major role in the initiation of coagulation in SAH.
View full abstract