Proteolytic degradation and receptor cleavage in the microcirculation

Geert W. SCHMID-SCHÖNBEIN Department of Bioengineering Institute of Engineering in Medicine University of California San Diego La Jolla California, 92093-0412 ABSTRACT We propose here a previously unrecognized pathogenic mechanism for hypertension and diabetes and the cluster of multifaceted cell dysfunctions characteristic of the metabolic syndrome. The evidence for this new hypothesis is derived from a genetic model with unchecked proteolytic activity, including that of matrix metalloproteinases, which causes cleavage of the extracellular domain of surface receptors and loss of their respective functions. For example, cleavage of the extracellular domain of the β2-adrenergic receptor promotes arteriolar vasoconstriction and elevates central blood…

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Recent findings in the pathogenesis of venous wall degradation

Michel René BOISSEAU1,2 Département de Pharmacologie Université Victor Segalen Bordeaux 2 Bordeaux, France SUMMARY Increased venous pressure in the erect position is a constant finding in patients with chronic venous disease. In the case of primary chronic venous disease, this increase in venous pressure is linked to venous reflux. A linear relationship exists between increased ambulatory venous pressure and skin ulceration. The length of time a subject is exposed to elevated venous pressure is a major factor in the progression of venous disease and in the development of varicose veins. The development of an animal model of venous hypertension (VHT)…

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Quantification of microangiopathy in chronic venous disease

C. E. VIRGINI-MAGALHÃES, C. L. LASCASAS PORTO, F. F. A. FERNANDES, D. M. DORIGO, D. A. BOTTINO, E. BOUSKELA Laboratory for Research in Microcirculation, State University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil ABSTRACT Analysis of microcirculatory changes in chronic venous disease (CVD) is challenging because we lack practical tools. The orthogonal polarization spectral (OPS) imaging technique used in the Cytoscan is less than ten years old and seems to be suitable for studying patients suffering from CVD. The Cytoscan has a small handheld probe which can be noninvasively applied to all body surfaces. CVD was studied using…

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