Plasma dopamine-beta-hydroxylase (DBH) activity in two kinds of acute stress in rabbits.

Changes in plasma dopamine-beta-hydroxylase (DBH) activity were studied in rabbits subjected to two kinds of acute stress: insulin-induced hypoglycaemia and fatigue. A significant elevation of DBH levels was found both 30 minutes after fatigue-induced stress (p less than 0.001) and 90 minutes after insulin injection (p less than 0.01) when compared with the control values. Responses to these two kinds of stress are reported to be mediated by the sympathetic nervous system, mainly by the adrenal glands. Thus, these results suggest that plasma DBH level is a good index of acute alterations in sympathetic activity in rabbits.