ABSTRACT
<p><b>OBJECTIVE</b>To dynamically observe the effect of Safflower Injection (SI) on mesenteric microvascular motion in vivo in rabbits, and to explore the effect of nitric oxide (NO) in the process to further investigate the action mechanism of activating blood to remove stasis of SI.</p><p><b>METHODS</b>Twenty healthy male albino rabbits were intraperitoneally injected with urethane for basic anesthesia and injected with alpha-chloralose via ear marginal venous to maintain anesthesia, spontaneously ventilated via tracheotomy tube, with the in-step record of breath and blood pressure. The vasomotion was induced by noradrenaline (NA) in vivo, then the changes of vasomotion after injecting SI and N(G)-monomethyl-L-arginine (L-NMMA, a NO synthase inhibitor) were measured respectively on a TV monitor using a TV camera mounted on the microscope, and the influence of L-NMMA on effect of SI was also observed.</p><p><b>RESULTS</b>L-NMMA injection alone can inhibit the NA induced vasomotion in vasoconstriction state, while SI injection alone can inhibit it in vaso-dilation state. SI could abolish the effect of L-NMMA on vasomotion but L-NMMA did not influence the effect of SI on vasomotion. CONCLUSION SI can inhibit vasomotion in vaso-dilation status, but its mechanism is not mediated by endogenous NO.</p>