Adaptation to arterial wall hypoxia demonstrated in vivo with oxygen microcathodes

Iliofemoral arteries of 9 rabbits were balloon de-endothelialized resulting in subintimal thickening. Contrary to expectation, enzyme and lactate determinations did not indicate arterial wall hypoxia when compared with arteries of 10 control rabbits. The explanation came from in vivo measurement of oxygen tension profiles across the de-endothelialized and control femoral arteries and from the subsequent histological findings. They showed that the impaired oxygen supply of the de-endothelialized arteries with subintimal thickening was counteracted by a centripetal oxygenation of the arterial wall obviously induced by proliferation of newly formed nutrient vessels in the adventitia. Such adaptation is an important mechanism against hypoxia induced by arterial injury and may be an essential protective factor in atherogenesis.