INDUCTION OF CALCIUM-INDEPENDENT NITRIC-OXIDE SYNTHASE ACTIVITY IN PRIMARY RAT GLIAL CULTURES
INDUCTION OF CALCIUM-INDEPENDENT NITRIC-OXIDE SYNTHASE ACTIVITY IN PRIMARY RAT GLIAL CULTURES
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DOI：
10.1073/pnas.89.22.10945
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发表时间：
1992-11-15
影响因子：
11.1
通讯作者：
REIS, DJ
中科院分区：
文献类型：
--
作者：
GALEA, E;FEINSTEIN, DL;REIS, DJ
暴露于细菌脂多糖（LPS）的新生大鼠皮层星形胶质细胞的原代培养物的结果在一氧化氮合酶（NOS）活性的外观。NOS的诱导，这是由放线菌素D阻断，是直接相关的暴露时间和剂量的LPS，和2小时的脉冲可以诱导酶的活性。来自LPS处理的星形胶质细胞培养物的胞质溶胶，而不是来自对照培养物的胞质溶胶，产生L-精氨酸向L-瓜氨酸的Ca 2+非依赖性转化，该转化可被特异性NOS抑制剂N（G）-单甲基-L-精氨酸完全阻断。诱导的NOS活性表现出对L-精氨酸的16.5 μ M的表观K（m），并且依赖于NADPH、FAD和四氢生物蝶呤。LPS也诱导NOS在C6胶质瘤细胞和小胶质细胞培养，但不是在培养的皮质神经元。NOS在星形胶质细胞和小胶质细胞中的表达已经通过使用小鼠巨噬细胞的诱导型NOS的抗体的免疫细胞化学染色和通过NADPH黄递酶活性的组织化学染色来证实。我们的结论是，中枢神经系统的胶质细胞可以表达一种诱导型的NOS类似的诱导型NOS的巨噬细胞。胶质细胞中的诱导型NOS可能通过产生一氧化氮而参与与脑缺血和/或脱髓鞘疾病相关的神经元损伤。
Exposure of primary cultures of neonatal rat cortical astrocytes to bacterial lipopolysaccharide (LPS) results in the appearance of nitric oxide synthase (NOS) activity. The induction of NOS, which is blocked by actinomycin D, is directly related to the duration of exposure and dose of LPS, and a 2-hr pulse can induce enzyme activity. Cytosol from LPS-treated astrocyte cultures, but not from control cultures, produces a Ca2+-independent conversion of L-arginine to L-citrulline that can be completely blocked by the specific NOS inhibitor N(G)-monomethyl-L-arginine. The induced NOS activity exhibits an apparent K(m) of 16.5 muM for L-arginine and is dependent on NADPH, FAD, and tetrahydrobiopterin. LPS also induces NOS in C6 glioma cells and microglial cultures but not in cultured cortical neurons. The expression of NOS in astrocytes and microglial cells has been confirmed by immunocytochemical staining using an antibody to the inducible NOS of mouse macrophages and by histochemical staining for NADPH diaphorase activity. We conclude that glial cells of the central nervous system can express an inducible form of NOS similar to the inducible NOS of macrophages. Inducible NOS in glia may, by generating nitric oxide, contribute to the neuronal damage associated with cerebral ischemia and/or demyelinating diseases.