Haemodynamic effects of loud noise in hypertensive patients treated with combined beta-adrenoceptor blockade and precapillary vasodilatation.
The effects of acute exposure to noise on central and regional (calf and forearm) haemodynamics were studied during placebo therapy and during combined nonselective beta-adrenoceptor blockade and precapillary vasodilatation in 9 patients with essential hypertension. On placebo therapy a loud noise (105 dBA for 10 min) caused a significant increase in diastolic and mean arterial pressure due to vasoconstriction. There was also a significant increase of vascular resistance in the calf. After combined precapillary vasodilatation and non-selective beta-adrenoceptor blockade, the increase in blood pressure during stimulation with noise was not prevented. Thus, systolic as well as diastolic and mean arterial pressures increased significantly. This indicates a temporary resetting of the baroreceptors, allowing a higher level of blood pressure during stimulation with noise. Such a resetting would involve the central nervous system pathways of the baroreflex and this would explain why the peripherally active therapeutic principle--precapillary vasodilatation and beta-adrenoceptor blockade--was unable to inhibit the blood pressure response induced by noise.
D000328:Adult; D005260:Female; D005542:Forearm / Q000098:blood supply; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D006973:Hypertension / Q000188:drug therapy* / Q000503:physiopathology; D007866:Leg / Q000098:blood supply; D008297:Male; D008875:Middle Aged; D009622:Noise / Q000009:adverse effects*; D011311:Pressoreceptors / Q000503:physiopathology; D011724:Pyridazines / Q000494:pharmacology*; D013312:Stress, Physiological / Q000503:physiopathology
D011724:Pyridazines; C024293:prizidilol