Nitric oxide synthase and cGMP activity in the salivary glands of the American dog tick Dermacentor variabilis
Nitric oxide synthase and cGMP activity in the salivary glands of the American dog tick Dermacentor variabilis
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DOI：
10.1006/expr.1999.4477
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发表时间：
2000-02-01
影响因子：
2.1
通讯作者：
Coons, LB
中科院分区：
文献类型：
--
作者：
Bhattacharya, ST;Bayakly, N;Coons, LB
我们共定位的一氧化氮合酶（NOS）的活性在上皮细胞周围的唾液腺导管在女性革蜱变异与NADPH黄递酶组织化学和免疫组化使用多克隆抗内皮NOS。使用尺寸排阻色谱法，洗脱从蜱的分子量约为185 kDa的心肌黄酶活性的馏分，唾液腺匀浆。该馏分将精氨酸转化为瓜氨酸，产生一氧化氮（NO），这是通过使用电子自旋共振光谱检测。心肌黄酶组分的完整活性依赖于NADPH、FAD、四氢生物蝶呤、钙调素（CaM）和Ca 2+，但不依赖于二硫苏糖醇。精氨酸类似物N-G-单甲基-L-精氨酸抑制该馏分的活性。NO和精氨酸激活可溶性鸟苷酸环化酶产生cGMP在多巴胺刺激的离体唾液腺。用含有EDTA、NOS抑制剂N-G-硝基-L-精氨酸甲酯或钙/CaM结合抑制剂W-7的蜱盐水处理多巴胺刺激的离体唾液腺，cGMP没有增加。NO供体硝普钠显着增加cGMP水平在未刺激的离体唾液腺。一个可能的功能，NO在唾液分泌这硬蜱进行了讨论。(C)北京大学出版社.
We colocalized nitric oxide synthase (NOS) activity in epithelial cells that surround the salivary gland duct in female Dermacentor variabilis with NADPH diaphorase histochemistry and immunohistochemistry using a polyclonal antiendothelial NOS. Using size-exclusion chromatography, a fraction with a molecular mass of about 185 kDa that had diaphorase activity was eluted from tick; salivary gland homogenate. This fraction converted arginine to citrulline with the production of nitric oxide (NO), which was detected by using electron spin resonance spectroscopy. The complete activity of the diaphorase fraction was dependent on NADPH, FAD, tetrahydrobiopterin, calmodulin, (CaM), and Ca2+, but was not dependent on dithiothreitol. The arginine analog N-G-monomethyl-L-arginine inhibited the activity of this fraction. NO and arginine activated soluble guanylate cyclase to produce cGMP in dopamine-stimulated isolated salivary glands. Dopamine-stimulated isolated salivary glands treated with tick saline containing either EDTA, the NOS inhibitor N-G-nitro-L-arginine methyl ester, or the calcium/CaM binding inhibitor W-7 showed no increase in cGMP. The NO donor sodium nitroprusside significantly increased cGMP levels in unstimulated isolated salivary glands. A possible function for NO in salivation by this ixodid tick is discussed. (C) 2000 Academic Press.