Value of venous occlusion plethysmography to study venoactive medication in men

Venous occlusion plethysmography is a useful tool to investigate the effect of a vaso-active medication on the venous circulation in man. However, room temperature can be very critical when small changes have to be detected. Therefore several authors induce a preconstriction of the veins for example with norepinephrine. When the conditions of the experiment are carefully controlled and a very sensitive plethysmograph is used, a significant effect on forearm veins can be shown even after small doses of nitrates and a high room temperature; matching with placebo is critically needed. It is likely that by lowering room temperature the response would be exaggerated. Taking these restrictions in mind, venous occlusion plethysmography can be a very valuable, non-invasive tool to study the effect of vaso-active treatment on the veins in men.