ABSTRACT
<p><b>OBJECTIVE</b>To investigate the effect of HHI-I (I) on the cerebral microcirculation, the blood-brain barrier permeability in rats and anti-hypoxic activity in mice.</p><p><b>METHODS</b>(1) The blood microcirculation of the brain in rats was investigated by laser Doppler flowmetry with the probes laid on the cerebral pia mater or inserted into the brain parenchyma. (2) The protective action of HHI-I against the brain microcirculation disturbance induced by intravenous injection of high-molecular dextran (10%, 9 mL/kg) was observed. (3) The protective effect of HHI-I against lethal hypoxia in mice was observed with a hypoxic chamber containing 5% oxygen. (4) The disruption of the blood-brain barrier (BBB) permeability in rats was caused by phenylephrine-induced hypertension, and the effect of intravenous injection of HHI-I on the BBB permeability was determined using Evans blue as the marker.</p><p><b>RESULTS</b>HHI-I could increase the blood flow of the cerebral microcirculation in rats and possess some protective effects on the brain microcirculatory disturbance. Besides, HHI-I could decrease the brain edema occurring in the process of lethal hypoxia in mice. While increasing the blood flow of brain, HHI-I could lower the BBB permeability in rats.</p><p><b>CONCLUSION</b>HHI-I has several beneficial effects on the cerebral microcirculation, blood-brain barrier in rats and anti-hypoxic activity in mice.</p>