The effect of O-(beta-hydroxyethyl)-rutosides (HR) on the skin capillary resistance of rats.

The effect of three different oral doses of O-(beta-hydroxyethyl)-rutosides (HR, Venoruton) on the skin capillary resistance (CR) of Sprague-Dawley rats aged 8-10 weeks, 6 months or 1 year (and selected because of their low CR) was investigated. The CR was measured over a period of 24 h after a single administration of each dose. The results were compared with a further group aged 6 months who received HR intraperitoneally. The optimal dose was defined in all four groups receiving the drug systemically. In most cases a significant effect could be shown already after 2-4 h, persisting until at least 8 h and in some cases 24 h. Comparative data were also obtained with four different pure hydroxyethyl components (tetra-HR, tri-HR, di-HR and mono-7-HR) in identical experimental conditions. The most active appeared to be the mono-7-HR. Finally, the effect of a single topical application of a gel containing 2% HR was investigated. This produced a significant increase of CR after 1 h, which lasted around 4-5 h. The clinical implications of these results are discussed with special reference to senile, hypertensive and diabetic vascular disease.