BETA-HYDROXYETHYL RUTOSIDES REVERSE THE INCREASED PERMEABILITY INDUCED IN FROG MICROVESSELS BY PROTEIN-FREE PERFUSIONS

Objective: To determine whether the five principal components of a sta ndardised mixture of hydroxyethyl rutosides (HR) can reverse the incre ase in permeability induced in single frog microvessels by perfusion w ith protein-free solutions. Design: Single mesenteric microvessels wer e perfused sequentially with solutions containing (a) Ficoll 70 and BS A; (b) Ficoll 70; (c) Ficoll 70 and either HR or one of its constituen ts. Hydraulic permeability (L(p)) and effective oncotic pressure (sigm aDELTApi) were measured during each perfusion by the micro-occlusion t echnique. Setting: Department of Physiology & Biophysics, St Mary's Ho spital Medical School, Imperial College of Science, Technology & Medic ine, London, UK. Results: L(p) doubled and sigmaDELTApi halved in the absence of albumin. Both HR and its component 7,4'di-HR reversed the i ncrease of L(p). HR but not 7,4'di-HR restored sigmaDELTApi to its con trol values. Components of HR (other than 7',4 di-HR) did not reverse the increase in L(p) induced by protein free perfusion. Conclusion: 7, 4'di-HR is largely responsible for HR reducing microvascular L(p) in a bsence of albumin.