[Changes in plasma dopamine-beta-hydroxylase activity in patients with acute subarachnoid hemorrhage (author's...

In 24 patients with subarachnoid hemorrhage (SAH) who were admitted within 48 hours after the onset, the activity of dopamine-beta-hydroxylase (DBH) in peripheral venous plasma was analyzed applying the method described by Nagatsu and Udenfriend (Clin. Chem., 18: 980-983, 1972) with a minor modification. Plasma samples were serially collected every a few days for three days to four weeks after the onset. DBH activity in peripheral venous plasma increased markedly after the onset, reaching the highest level within 48 hours, and thereafter declined time-dependently for about two weeks. There was no significant difference in the plasma DBH activities on admission between patients with and without cerebrovascular spasm revealed by angiography. The decline of the activity was significantly remarkable in patients with spasm compared with those without spasm. The difference was most prominent around the 7th day after the onset when spasm was shown most frequently. Neurosurgery or administration of analgesics and/or sedatives had little effect on the changes in plasma DBH activity in acute SAH. The activity correlated with the pressure of cerebrospinal fluid (r = 0.587, P less than 0.05), when it was higher than the normal range. With these results we obtained following: 1) The activity of sympathetic nervous system increases following SAH for a week after the onset. 2) The activity declines more rapidly in patients with cerebrovascular spasm than those without spasm, when it was judged from the activity of plasma DBH activity.