EFFECT OF WORK LOAD ON PLASMA DOPAMINE -β-HYDROXYLASE ACTIVITY AND CORTISOL IN PATIENTS WITH ESSENTIAL HYPERTENSION

Abstract

Physical work load activates the sympathoadrenomedullar as well as the adrenocortical system in healthy subjects. This chapter focuses on the response of the sympathicus and of the adrenal to physical work load in young patients with essential hypertension at the early stage of the illness. The influence of a single submaximal physical work load (PWL) on the blood pressure, the activity of dopamine-β-hydroxylase (DBH) in the serum, and the level of the total cortisol (F) in the plasma in patients with essential hypertension and in healthy volunteers, have been observed. Following the physical work load, in the hypertensive and normotensive subjects, it was observed that there is a rise in the systolic but a decrease in the diastolic blood pressure. The normotensive and hypertensive subjects reacted by a change in their blood pressure differently to the mental and to the physical work load. On the basis of the increase of serum DBH activity and increase of total plasma cortisol during physical work load of the young patients with essential hypertension at the initial stage of the illness, an increased readiness of the sympathetic nervous system and of the adrenal to react to a physical work load is assumed in comparison with the normotensive subjects.