Dopamine-beta-hydroxylase activity after acute myocardial infarction.

Serum dopamine-beta-hydroxylase (DBH) activities of 74 apparently healthy adults were not distributed normally, but skewed to the right. There were at least 2 subgroups in the distribution of DBH activity. Accordingly, 27 serial serum DBH activities following acute myocardial infarction were divided into 2 subgroups according to their activities on the 10th day or/and thereafter. The DBH activity was significantly elevated on the 1st day with average of 157% of the 10th day (p less than 0.015) in high DBH subgroup and also significantly elevated on the 1st and 2nd day with the average of 182% and 155%, respectively, of the 10th day (p=0.025 and p less than 0.05) in low DBH subgroup. There was no significant difference between the DBH activity of patients with anterior myocardial infarction and that of patients with inferior myocardial infarction. No significant correlation between the DBH activity and the coronary prognostic index was found. The observed elevation of the DBH activity on the 1st and 2nd day suggests an augmentation in the sympathetic nervous activity after acute myocardial infarction.