Diffusion and reaction of nitric oxide in suspension cell cultures
Diffusion and reaction of nitric oxide in suspension cell cultures
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DOI：
10.1016/s0006-3495(98)77564-2
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发表时间：
1998-08-01
影响因子：
3.4
通讯作者：
Deen, WM
中科院分区：
文献类型：
--
作者：
Chen, B;Keshive, M;Deen, WM
建立了一个反应扩散模型来预测免疫系统细胞释放的一氧化氮（NO）的命运。该模型用于分析先前使用附着于悬浮在搅拌容器中的微载体珠粒的巨噬细胞获得的数据。活化的巨噬细胞合成NO，其在培养基中被分子氧和超氧化物（O-2（-），也由细胞释放）氧化，主要产生亚硝酸盐（NO2-）和硝酸盐（NO3-）作为各自的终产物。在分析中，将反应器分成“停滞膜”，其具有邻近代表性载体珠和充分混合的本体溶液的位置依赖性浓度。结果表明，薄膜中NO的浓度比较均匀.相比之下，由于O-2（-）与NO反应生成过氧亚硝酸盐，计算出基本上所有的O-2（-）都消耗在细胞表面约2 μ m的范围内。过亚硝酸盐的分解导致其浓度在距离细胞约30 μ m的距离内降至几乎为零。虽然膜区域（其具有63 μ m的有效厚度）仅占反应器体积的2%，并且在控制条件下预测仅占NO2形成的6%，但它们被计算为负责NO3形成的99%。预计培养基中的超氧化物歧化酶（3.2 μ M）可降低NO3-与NO2-形成速率的比率，
A reaction-diffusion model was developed to predict the fate of nitric oxide (NO) released by cells of the immune system. The model was used to analyze data obtained previously using macrophages attached to microcarrier beads suspended in a stirred vessel. Activated macrophages synthesize NO, which is oxidized in the culture medium by molecular oxygen and superoxide (O-2(-), also released by the cells), yielding mainly nitrite (NO2-) and nitrate (NO3-) as the respective end products. In the analysis the reactor was divided into a "stagnant film" with position-dependent concentrations adjacent to a representative carrier bead and a well-mixed bulk solution. It was found that the concentration of NO was relatively uniform in the film. In contrast, essentially all of the O-2(-) was calculated to be consumed within similar to 2 mu m of the cell surfaces, due to its reaction with NO to yield peroxynitrite. The decomposition of peroxynitrite caused its concentration to fall to nearly zero over a distance of similar to 30 mu m from the cells. Although the film regions (which had an effective thickness of 63 mu m) comprised just 2% of the reactor volume and were predicted to account for only 6% of the NO2- formation under control conditions, they were calculated to be responsible for 99% of the NO3- formation. Superoxide dismutase in the medium (at 3.2 mu M) was predicted to lower the ratio of NO3- to NO2- formation rates from near unity to