Plasma dopamine-beta-hydroxylase activity and catecholamine levels in anesthetized dogs following acute hemorrhage.

Because dopamine-beta-hydroxylase (DBH) is released from storage vesicles in adrenergic nerves and the adrenal medulla along with catecholamines, determination of circulating levels of this enzyme might serve as an index of sympathoadrenal activity. This hypothesis has been studied in dogs anesthetized with cyclopropane, isoflurane, and thiopental that were subjected to a single acute hemorrhage and followed for 5 hours. Plasma DBH activity and catecholamine levels were determined before and every 30 minutes after the hemorrhage. Changes in DBH activity did not correlate well with changes in levels of circulating catecholamines in the dog in response to this form of stress.