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Effects of hydroxyethylrutosides on the permeability of microvessels in the frog mesentery

1993; Wiley; Volume: 110; Issue: 1 Linguagem: Inglês

10.1111/j.1476-5381.1993.tb13792.x

1476-5381

S. Kendall, R. Towart, C. C. Michel,

Blood transfusion and management

We have investigated the effects of a standardised mixture of hydroxyethylrutosides (HR, Venoruton), a mixture of five of its main components (M) and each of the five components separately (7‐mono‐HR, 7,4′‐di‐HR, 7,3′,4′‐tri‐HR, 5,7,3′,4′‐tetra‐HR and 7,3′4′‐tri HQ) upon the permeability of single perfused capillaries and venules in the mesenteries of pithed frogs. In each experiment, the hydraulic permeability (L p ) of a single perfused microvessel and the effective osmotic pressure (σΔπ) exerted by macromolecules across its walls were estimated by a microcclusion technique, first during control perfusion and then in the presence of a known concentration of test substance. HR, M and 7,4′‐di‐HR reduced L p in a similar concentration‐dependent manner over the range of 1 μg ml −1 to 1 mg ml −1 (maximum reduction was to 40% of control L p at 1 mg ml −1 ). At perfusate concentrations greater than 1 mg ml −1 , these substances reduced L p to a lesser extent. While the four other test substances reduced L p significantly when their perfusate concentrations equalled or exceeded 100 μg ml −1 , they were all less potent than 7,4′‐di‐HR. The reduction in L p induced by the mixture of flavonoids was only slightly reversed by subsequent perfusion with flavonoid‐free solutions. When permeability was increased by perfusing with protein‐free solutions, both HR and 7,4′‐di‐HR reduced and then reversed the increase in L p in a concentration‐dependent manner over the range of 1 μg ml −1 to 100 μg ml −1 . None of the other component flavonoids was effective in restoring L p under these conditions.