[Serial measurement of bradykinin of the cerebrospinal fluid in patients with subarachnoid hemorrhage].

The bradykinin (BK) concentration of the cerebrospinal fluid (CSF) in 21 patients with subarachnoid hemorrhage (SAH) was measured serially by radioimmunoassay (RIA). The values were 134.9 +/- 93.9 pg/ml (mean +/- standard deviation) on the day of onset, 38.3 +/- 31.8 pg/ml on the first day after onset, 23.4 +/- 22.8 pg/ml on the second day, 16.6 +/- 9.9 pg/ml on the third day, 15.5 +/- 6.0 pg/ml on the fourth day, and 14.8 +/- 5.9 pg/ml on the fifth day. In the controls the BK concentration in the CSF was 8.0 +/- 3.3 pg/ml (n = 10). On the other hand, none of 5 patients with intraventricular hematoma due to intracerebral hemorrhage had a high level of BK in the bloody CSF at the initial stage (15.2-26.0 pg/ml). This shows that BK is not produced only by the mixture of CSF and blood. BK is produced by the activation of Hageman factor that is considered to be activated by trabecula of collagen bundles in the subarachnoid space in the case of SAH.