Bunnett N W, Wu V, Sternini C, Klinger J, Shimomaya E, Payan D, Kobayashi R, Walsh J H
Department of Surgery, University of California, San Francisco 94143.
Am J Physiol. 1993 Mar;264(3 Pt 1):G497-508. doi: 10.1152/ajpgi.1993.264.3.G497.
The distribution of neutral endopeptidase (NEP; EC 3.4.24.11) was examined in the alimentary tract of the rat. Immunoreactive NEP and NEP mRNA were localized to epithelial cells of the small intestine and to muscle cells in the stomach, small intestine, and colon by immunohistochemistry and in situ hybridization histochemistry. NEP antisera recognized a protein on Western blots of membranes from gastric, jejunal, and colonic mucosa and gastric muscle with an electrophoretic mobility identical to that of recombinant human NEP (approximately 95 kDa). An antisense cRNA probe to NEP hybridized to RNA of approximately 3.5 kb and approximately 6.5 kb, corresponding to the primary transcripts of rat NEP, on Northern blots of total RNA from the jejunal mucosa. NEP message was detected in mRNA from jejunal and colonic mucosa and gastric, jejunal, and colonic muscle using a ribonuclease protection assay. NEP enzymatic activity, assessed by DL-thiorphan-inhibitable degradation of glutaryl-Ala-Ala-Phe-4-methoxy-2-naphthylamine, was highest in homogenates of jejunal mucosa (868 +/- 98 pmol.h-1 x micrograms protein-1) and was between 49- and 413-fold lower in other gastrointestinal tissues. The cellular origin of NEP in the gastric and colonic mucosa could not be determined.
在大鼠的消化道中检测了中性内肽酶（NEP；EC 3.4.24.11）的分布。通过免疫组织化学和原位杂交组织化学，免疫反应性NEP和NEP mRNA定位于小肠的上皮细胞以及胃、小肠和结肠的肌肉细胞。NEP抗血清在胃、空肠和结肠黏膜以及胃肌肉的膜的蛋白质免疫印迹上识别出一种蛋白质，其电泳迁移率与重组人NEP（约95 kDa）相同。在空肠黏膜总RNA的Northern印迹上，针对NEP的反义cRNA探针与约3.5 kb和约6.5 kb的RNA杂交，对应于大鼠NEP的初级转录本。使用核糖核酸酶保护试验在空肠和结肠黏膜以及胃、空肠和结肠肌肉的mRNA中检测到NEP信息。通过DL-硫氧还蛋白抑制的戊二酰-Ala-Ala-Phe-4-甲氧基-2-萘胺降解评估的NEP酶活性在空肠黏膜匀浆中最高（868±98 pmol·h⁻¹×μg蛋白质⁻¹），在其他胃肠道组织中低49至413倍。无法确定胃和结肠黏膜中NEP的细胞来源。
