REACTIVE HYPERAEMIA IN THE HUMAN FOREARM

Reactive hyperaemia in the human forearm has been studied following 5, 10 and 15 min occlusion of the circulation using mercury‐in‐rubber strain gauges. Following 5 min occlusion the initial high blood flows declined exponentially with a half‐life ranging from 14 to 45 s. After 10 and 15 min occlusion the flow pattern is represented by a plateau followed by an exponential of similar time course to the above. Flows did not decay totally along this exponential but deviated onto a second, slower exponential with half‐lives ranging from 50 to 560 s. The hyperaemia represented by the area under the second exponential makes a greater contribution to the total flows in non‐muscular tissues. It is suggested that this phase of the hyperaemia may be the result of tissue warming during the initial period of high flows.