Abstract
It is well known that many stressors affect areas of the circulation system such as the heart and blood vessels through neuronal and humoral mechanisms. However, the effect of stress on blood fluidity as an important factor of the circulation system is not clarified yet. Elevation of blood fluidity increases vessel resistance by Poiseuille's low and enhances blood coagulation. Elevated blood fluidity increases blood pressure and a risk of thrombosis. Therefore we studied the effects of restraint stress on blood fluidity of rats by MC-FAN (micro channel array flow analyzer) which mimics capillary vessels. Aspirin (0.5 mg/kg, ip) enhanced the blood fluidity. This result indicates the reliability of MC-FAN. Restraint stress in a small box for 6 hours reduced blood fluidity of male Wistar rats. Phentolamine as an α-blocker (0.5 mg/kg, ip) enhanced blood fluidity. These results indicate that restraint stress might reduce blood fluidity at least partly through the noradrenaergic system.
