[The venous-arteriolar reflex].

Cutaneous blood flow (Xenon clearance) and transcutaneous pO2 were simultaneously measured on the foot of normal subjects and patients suffering from severe arterial insufficiency of the lower limbs. When the subject is sitting, cutaneous blood flow decreases, as well in normal subjects than in most patients with arterial insufficiency. However, tc pO2 increases in sitting position, probably because local vasoregulation is abolished by local heating. Increase in tc pO2 in sitting position is higher in patients in whom tc pO2 was very low in lying position. In normal subjects, there is a positive correlation between cutaneous blood flow and tc pO2. This correlation do not exist in patients suffering from severe ischemia; it is likely that Xenon clearance actually measures total cutaneous blood flow, while tc pO2 constitutes an index of nutritional circulation. It is also possible that Xenon clearance is modified by changes in partition coefficient in ischemia areas.