MUSCLE BLOOD FLOW IN NORMAL AND HYPERTENSIVE SUBJECTS - INFLUENCE OF AGE, EXERCISE, AND BODY POSITION

Blood flow in the tibialis anterior muscle was measured using the 133Xe local clearance technique in hypertensive and normal male subjects of different ages, at rest, and after maximum ischemic exercise recumbent, sitting and standing. Muscle blood flow measured by this technique decreases with age both in hypertensive and normal subjects. At rest in hypertension, both muscle flow and resistance are increased compared to the normal group, indicating that the muscle vessels share the increased resistance, but probably to a lesser extent than the total circulation. Assuming the upright position muscle blood flow determined after ischemic exercise decreases in normal subjects; this change was even more pronounced in hypertensive patients. © 1969.