Affiliations: Department of Physiology, Faculty of Medicine, Srinakharinvirot University, Bangkok 10110, Thailand | Department of Physiology, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand | National Cardiovascular Center Research Institute, Osaka 565-8565, Japan
Abstract: This study was conducted to investigate effects of Yahom on the regional cerebral blood flow (rCBF) in rats using fluorescence videomicroscopy. Male Wistar Furth rats weighing 200–250 g were used, and divided into three groups: experimental I, II and control groups. The experimental I and II groups received single oral administration of Yahom 2 and 4 g/kg.bw, and topical application of Yahom on the pial cerebral cortex, respectively, while the control group received oral administration of 1 ml of 5% Tween. The rCBF was monitored using laser Doppler flowmetry at different periods (5–120 minutes) after the administration of Yahom or Tween. The mean arterial pressure (MAP) was measured through a femoral artery. The cerebral microcirculation was observed and recorded under an intravital fluorescence videomicroscopic system. The arteriolar diameter was measured based on the recorded videomicroscopic images. The MAP and rCBF increased after the oral administration of Yahom, while they did not alter in the control group. The maximum responses of MAP and rCBF were approximately 16% and 33% at 45 min and 30 min after the administration of Yahom 4 g/kg.bw, respectively. The topical application of Yahom induced vasodilation in the pial microvessels. In conclusion, single oral administration of Yahom may increase the regional cerebral blood flow under the effect of cerebral microvascular vasodilation.
