Young H M, Furness J B, Shuttleworth C W, Bredt D S, Snyder S H
Department of Physiology, University of Melbourne, Parkville, Victoria, Australia.
Histochemistry. 1992 May;97(4):375-8. doi: 10.1007/BF00270041.
Neuronal nitric oxide synthase (NOS), an enzyme capable of synthesizing nitric oxide, appears to be identical to neuronal NADPH diaphorase. The correlation was examined between NOS immunoreactivity and NADPH diaphorase staining in neurons of the ileum and colon of the guinea-pig. There was a one-to-one correlation between NOS immunoreactivity and NADPH diaphorase staining in all neurons examined; even the relative staining intensities obtained were similar with each technique. To determine whether pharmacological methods could be employed to demonstrate that NADPH diaphorase staining was due to the presence of NOS, tissue was pre-treated with NG-nitro-L-arginine, a NOS inhibitor, or L-arginine, a natural substrate of NOS. In these experiments on unfixed tissue, it was necessary to use dimethyl thiazolyl tetrazolium instead of nitroblue tetrazolium as the substrate for the NADPH diaphorase histochemical reaction. Neither treatment caused a significant decrease in the level of NADPH diaphorase staining, implying that arginine and NADPH interact at different sites on the enzyme.
神经元型一氧化氮合酶（NOS）是一种能够合成一氧化氮的酶，它似乎与神经元型NADPH黄递酶相同。研究了豚鼠回肠和结肠神经元中NOS免疫反应性与NADPH黄递酶染色之间的相关性。在所检查的所有神经元中，NOS免疫反应性与NADPH黄递酶染色之间存在一一对应关系；甚至用每种技术获得的相对染色强度也相似。为了确定是否可以采用药理学方法来证明NADPH黄递酶染色是由于NOS的存在，用NOS抑制剂NG-硝基-L-精氨酸或NOS的天然底物L-精氨酸对组织进行预处理。在这些对未固定组织的实验中，有必要使用二甲基噻唑基四氮唑代替硝基蓝四氮唑作为NADPH黄递酶组织化学反应的底物。两种处理均未导致NADPH黄递酶染色水平显著降低，这意味着精氨酸和NADPH在该酶的不同位点相互作用。
