RayChaudhury A, Frischer H, Malik A B
Department of Pharmacology, Rush Medical College, Chicago, Illinois 60612, USA.
J Cell Biochem. 1996 Nov 1;63(2):125-34. doi: 10.1002/(sici)1097-4644(19961101)63:2<125::aid-jcb1>3.0.co;2-#.
S-nitroso-N-acetyl-D,L-acetylpenicillamine (SNAP), a chemical donor of NO, inhibited serum- and basic fibroblast growth factor (bFGF)-stimulated cultured endothelial cell (EC) proliferation in a dose-dependent manner. The inhibitory effect of NO was reversible after washoff of SNAP-containing media. Measurement of nitrate and nitrite in the media of SNAP-treated EC indicated that decomposition of SNAP into NO reached a stable level at or before 24 h; proliferation of EC was significantly inhibited for another 48 h and recovered thereafter if no additional SNAP was added. The level of NO produced by inhibitory concentrations of SNAP was comparable to NO levels produced by the induction of inducible nitric oxide synthase (iNOS) in smooth muscle cells or retinal pigmented epithelial cells. The growth-inhibitory effect of NO was unlikely to be due to cytotoxicity since 1) cells never completely lost their proliferative capacity even after 10 days of exposure to repeated additions of SNAP, 2) the inhibitory effect was reversible upon removal of NO and with the passage of time, and 3) NO did not reduce the number of cells that were growth-arrested with TGF-beta 1. In addition to its mitogenic effect, bFGF induced pronounced phenotypic changes, including suppression of contact inhibition, altered cell morphology, and scattering of the cells, in BPAEC cultures, whereas cells treated simultaneously with bFGF and NO did not exhibit these changes. These observations suggest that NO contributes to the regulation of angiogenesis and reendothelialization, processes that require EC proliferation, migration, and differentiation.
S-亚硝基-N-乙酰-D,L-青霉胺（SNAP），一种一氧化氮（NO）的化学供体，以剂量依赖的方式抑制血清和碱性成纤维细胞生长因子（bFGF）刺激的培养内皮细胞（EC）增殖。去除含SNAP的培养基后，NO的抑制作用是可逆的。对经SNAP处理的EC培养基中的硝酸盐和亚硝酸盐进行测量表明，SNAP分解为NO在24小时或之前达到稳定水平；EC的增殖在另外48小时内受到显著抑制，如果不添加额外的SNAP，此后会恢复。抑制浓度的SNAP产生的NO水平与平滑肌细胞或视网膜色素上皮细胞中诱导型一氧化氮合酶（iNOS）诱导产生的NO水平相当。NO的生长抑制作用不太可能是由于细胞毒性，因为1）即使在反复添加SNAP暴露10天后，细胞也从未完全丧失其增殖能力；2）去除NO并随着时间推移，抑制作用是可逆的；3）NO并没有减少被转化生长因子-β1（TGF-β1）生长阻滞的细胞数量。除了其促有丝分裂作用外，bFGF在牛肺动脉内皮细胞（BPAEC）培养物中还诱导了明显的表型变化，包括接触抑制的抑制、细胞形态改变和细胞散射，而同时用bFGF和NO处理的细胞没有表现出这些变化。这些观察结果表明，NO有助于调节血管生成和再内皮化过程，这些过程需要EC增殖、迁移和分化。
