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目的：研究瘦素对大鼠主动脉内皮细胞(RAECs)环氧化酶-2(COX-2)及其下游产物前列环素和血栓素A2表达的影响。方法：酶消化法分离RAECs；免疫荧光检测细胞Ⅷ因子的表达；实时荧光定量PCR检测不同浓度瘦素(10-10M、10-9M、10-8 M)和时间(36 h、48 h)处理后对RAECs COX-2 mRNA表达的影响；Western blot 检测各组COX-2 蛋白的改变；酶联免疫吸附测定(ELISA)检测各组细胞上清液中6-酮前列腺素F1琢(6-Keto PGF1琢)和血栓素B2(TXB2)的水平。结果：酶消化法6 天后见细胞呈长梭形或多边形，培养10 天后细胞呈典型的" 铺路石" 样改变，免疫荧光检测发现Ⅷ因子在胞浆中特异性表达，内皮细胞纯度达90 %。与对照组(PBS处理)相比较，瘦素处理后，各组大鼠主动脉内皮细胞COX-2 mRNA及蛋白表达量均有升高趋势，两者表达量均随浓度增加和处理时间延长而升高(P<0.05)。而6-Keto PGF1-alpha水平升高及TXB2/6-Keto PGF1-alpha比例降低仅见于相对高浓度瘦素(10-9、10-8 M)处理后(P<0.05)，但瘦素对RAECs TXB2表达无影响(P>0.05)。结论：瘦素增加RAECs炎性标志物COX-2及其下游舒张血管产物6-Keto PGF1琢的表达，降低TXB2（收缩血管物质）/6-Keto PGF1琢比例。COX-2 可能在瘦素介导的高血压发病中起重要作用，但因其下游产物则有利于血管舒张，故选择性COX-2 抑制剂可能会增加高血压风险。

英文摘要:

Objective:To study the effect of leptin on the expression levels of cyclooxygenase-2 (COX-2) and its downstream products prostacyclin and thromboxane A2 by rat aortic endothelial cells (RAECs).Methods:The separation of RAECs was carried out by enzyme digestion method; Cytoplasm Ⅷ factor was tested by immunoflurescence; The expression of RAECs COX-2 mRNA treatmented with different concentrations(10-10M,10-9M,10-8M) of leptin at different time(36 h,48 h) was detected by quantificational real time polymerase chain reaction; COX-2 protein was measured by western blot; The levels of 6-Keto prostaglandin F1琢(6-Keto PGF1-alpha) and thromboxane B2(TXB2) fromcell culture supernate were detected by enzyme linked immunosorbent assay(ELISA).Results:Six days after followed by enzyme digestion, cells presented a shuttle or polygon shape. The cells cultured for 10days showed a typical"paving stone" appearance. Cytoplasm Ⅷ factor specific expression was detected by immunofluorescence emanation, the purity of endothelial cells reached 90 %. Comparing with control group (PBS), RAECs treated by leptin had tended to increase the expression levels of COX-2 mRNA and protein. Both of those rose with the increase of concentration and processing time (P<0.05). 6-Keto PGF1-alpha increased and the proportion of TXB2/6-Keto PGF1-alphareduced only in relatively high concentrations of leptin (10-9 M、10-8M) (P<0.05), but leptin had no influence on TXB2 expression (P>0.05).Conclusion:The addition of leptin increased expression level of inflammatory marker COX-2 and its downstreamvasorelaxation product 6-keto PGF1-alpha expression, also decreased the ratio of TXB2 (vasoconstrictor)/ 6-Keto PGF1-alpha in vitro. COX-2 may play an important role in the incidence of hypertension mediated by leptin. However, its downstream products are benefit to vasodilatation. Therefore, selective COX-2 inhibitors may increase the risk of hypertension.

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