一氧化氮对小鼠胚胎围植入期子宫VEGF及其受体表达的调节

为研究NO在胚胎植入中的作用机理 ,本文采用子宫角注射、原位杂交及Westernblot方法研究了一氧化氮 (NO)在小鼠胚胎植入过程中对血管内皮生长因子 (VEGF)及其受体表达的调节。受试小鼠于妊娠第三天 (D3 )在一侧子宫角内注射一氧化氮合酶 (NOS)抑制剂N 硝基 L 精氨酸甲酯 (L NAME)或者L NAME与NO的供体硝普钠 (SNP)合用 ,另一侧子宫角为对照侧 ;收集并分别检测了D5,D6和D7天小鼠子宫中VEGF及其受体mRNA和蛋白的表达情况。结果显示 :与对照侧相比 ,L NAME处理后小鼠胚胎围植入期子宫中VEGF及其受体mRNA的表达有不同程度的下降 ;对VEGF及其受体蛋白表达水平检测表明 ,抑制的NO产生也使VEGF及其受体蛋白在小鼠围植入期子宫中的表达有不同程度的降低。当NOS抑制剂和NO的供体SNP同时注射小鼠时 ,VEGF及其受体mRNA和蛋白表达都恢复到正常水平。以上结果表明 ,在小鼠胚胎植入中NO可通过调节VEGF及其受体的表达参与血管新生 ,从而对胚胎植入起到调节作用

Effect of NO on the expression of VEGF and its receptors in mouse uterus during peri-implantation

Nitric oxide (NO) is believed to play a pivotal role in embryo implant ation. Successful embryo implantation depends upon the synchronized roles of hor mones and a series of cytokines, and this event is accompanied by angiogenesis. As an angiogenic and vascular permeability factor, vascular endothelial growth f actor (VEGF) is essential for endometrium development and placental vascular fun ction during early pregnancy. The purpose of this study was to investigate the e ffect of NO on VEGF and its receptors, as well as the mechanism of NO during mou se implantation using intrauterine injection, in situ hybridization, and wes tern blotting techniques. Nitric oxide synthase (NOS) inhibitor, N-nitro-L-argini ne methyl ester (L-NAME) was administered with or without sodium nitroprusside (SN P ), NO donor, into one uterine horn on day 3 of pregnancy, and the contralateral uterine horn served as the control. We collected the uteri on days 5, 6, and 7 o f pregnancy and examined the expression of VEGF and its receptors. The results s howed that, compared with the control, the expression of VEGF and its receptors mRNAs declined in L-NAME-treated uteri during peri-implantation. Similarly, t he western blotting results indicated that the protein levels of VEGF and its recep tors decreased during peri-implantation. The L-NAME-mediated effect on the ex pre ssion of VEGF and its receptors reversed when SNP was co-administered with L-N AM E. These data suggested that inhibition of NO production regulated the expressio n of VEGF and its receptors during peri-implantation, which may have serious co nsequences on embryo implantation.