DISTENSIBILITY OF THE PAPAVERINE-INDUCED PASSIVE VASCULAR BED IN DERMIS OF GENERALIZED SCLERODERMA

Passive distensibility of the vascular bed in cutaneous tissue of the hand was examined in 7 normal persons and 15 patients suffering from generalized scleroderma of the acrosclerosis type. Paralysis of vascular smooth muscle cells was obtained by locally injected papaverine. Increase in vascular transmural pressure was induced by lowering the limb. Blood flow was estimated by the local 133Xenon wash-out technique. There was no significant difference between the patients and the normals in relative blood flow during lowering, when injection volumes of 0.005 and 0.02 ml were used, indicating that distensibility of the vascular bed in cutaneous tissue in generalized scleroderma is not diminished. However, in generalized scleroderma an injection volume of 0.1 ml caused a significant decrease in relative blood flow during lowering. This phenomenon observed in the patients probably reflects changes in total tissue pressure opposing distension of the vascular bed. This suggests an altered pressure-volume relationship of the interstitial fluid spaces in cutaneous tissue of generalized scleroderma.