Multiple and Simultaneous Blood Flow Measurements by the Ultrasonic Doppler Technique in Man, With Special Reference to the Circulatory Effects of Induced Hypertension on Internal and External Carotid Arteries and Brachial Artery

The vascular reactivity in the internal carotid artery, external carotid artery and brachial artery during induced hypertension (intravenous administration of noradrenalin) was investigated in man in situ simultaneously by means of the ultrasonic Doppler apparatus equipped with a newly devised probe and on-line real-time data processing system. The hemodynamic autoregulation and/or nor-adrenalin sensitivity is generally higher in the internal carotid artery than In the external carotid artery. However, there seem to be some subjects in whom vascular reactivity is opposite or antagonistic to the above pattern. Therefore, it is suggested that the vascular reactivity in these three arteries is indefinite and complicated according to the subjects.