Albina J E, Henry W L
Department of Surgery, Rhode Island Hospital, Providence 02903.
J Surg Res. 1991 Apr;50(4):403-9. doi: 10.1016/0022-4804(91)90210-d.
The amino acid L-arginine can be metabolized through a nitric oxide-synthesizing pathway (NOSP) to produce L-citrulline and reactive nitrogen intermediates. Among these nitrogen intermediates, NO has been implicated as the mediator of a variety of biological effects including vasodilatation, inhibition of platelet aggregation, tumor cytotoxicity and microbiostasis by activated macrophages and generalized suppression of macrophage functions. Work reported here demonstrated that the NOSP is expressed in Con A-stimulated rat splenic cell (SC) cultures and is associated with a profound suppression of lymphocyte proliferation. Inhibition of the NOSP by NG-monomethyl-L-arginine (N-MMA) or binding of its products by hemoglobin, either free in solution or contained in RBC, markedly promotes rat SC mitogenic response to Con A. Mouse SC do not express the NOSP under the conditions used in these experiments. Consequently, their mitogenic response to Con A is not affected by N-MMA or hemoglobin. These data confirm and expand the apparent role of NO as a regulator of immune responses while indicating potentially important species differences.
氨基酸L-精氨酸可通过一氧化氮合成途径（NOSP）进行代谢，生成L-瓜氨酸和活性氮中间体。在这些氮中间体中，NO被认为是多种生物学效应的介质，包括血管舒张、抑制血小板聚集、肿瘤细胞毒性以及活化巨噬细胞的微生物抑制作用和巨噬细胞功能的普遍抑制。此处报道的研究表明，NOSP在刀豆蛋白A刺激的大鼠脾细胞（SC）培养物中表达，并与淋巴细胞增殖的显著抑制有关。用NG-单甲基-L-精氨酸（N-MMA）抑制NOSP，或用溶液中游离的或红细胞中所含的血红蛋白结合其产物，均可显著促进大鼠脾细胞对刀豆蛋白A的促有丝分裂反应。在这些实验所用的条件下，小鼠脾细胞不表达NOSP。因此，它们对刀豆蛋白A的促有丝分裂反应不受N-MMA或血红蛋白的影响。这些数据证实并扩展了NO作为免疫反应调节因子的明显作用，同时表明了潜在的重要物种差异。
