AIMTo observe the effect of homocysteine (HCY) on the function of endothelium cell, and to discuss the possible mechanisms that Tongxinluo super powder affected.

METHODSHealthy male Wistar rats were divided into randomly the control group, the model group, the Tongxinluo group. The effect of Ach on isolated rat thoracic aorta in vitro was examined, the microcirculation was observed by microcirculation meter, the activity of SOD and GSH-PX and content of NO, MDA, ET, Ang II, TXA2, PGI2 was detected.

RESULTSCompared with control group, the effect of Ach on isolated rat thoracic aorta in vitro weakened markablely (P < 0.01), the format and percentage that capillary dilated declined significantly (P < 0.05), after treatment with Tongxinluo powder, the effect of Ach on isolated rat thoracic aorta in vitro was improved obviously (p < 0.01), and the format and percentage that capillary dilated were increased compared with model group; comparing with the control group, the level of Ang II and ET, TXA2 in plasm increased obviously (P < 0.05, P < 0.01), while the content of PGI2 depressed manifestly (P < 0.05), at the same time, both content of NO and activity of SOD, (GSH-PX declined obviously (P < 0.001, P < 0.05). After treatment with Tongxinluo powder, the level of ET, AngII and TXA2 reduced significantly in different degree (P < 0.01), while the content of PGI2 appeared stepping up notably (P < 0.01), and both activity of SOD and NO level increased obviously (P < 0.01, P < 0.05).

CONCLUSION(1) The high homocystein might cause the contracted and dilated function decreased, it might get involved in endothelium disfunction as a result of the massive free radicals production and diastolic-contract factors balance disorder induced by high homocystein. (2) Tongxinluo powder could improve the function of endothelium-dependment dilation induced by high homocystein, that associated with inhibitting the excessive production of free radicals, and improved function of endothelium.