Biochemical and hislogical studies of nitric oxide (NO) in neuromuscular disorders.

[1]人体肌肉组织中一氧化氮合酶（NOS）和超氧化物歧化酶（SOD）的组织学测定：对肌肉组织组织中Mn-SOD进行免疫组化分析。线粒体脑肌病中Mn-SOD主要存在于红布纤维的肌下区。Mn-SOD阳性纤维可用于线粒体脑肌病的诊断。此外，通过对神经元型NOS （nNOS）和内皮型NOS （ec-NOS）进行免疫组化分析，确定病变肌肉中一氧化氮合酶的定位。nNOS免疫染色在不规则红纤维的肌层区明显。Ec-NOS在红破纤维肌原纤维中呈强阳性。结果表明，SOD和NOS在线粒体脑肌瘤患者的肌肉中具有重要意义。在多发性肌炎中，坏死或再生纤维的nNOS和NADH-diaphorase染色较差骨骼肌坏死或再生纤维中肌萎缩蛋白相关蛋白的组织学定位：采用心脏毒素注射大鼠骨骼肌制备骨骼肌纤维坏死或再生模型。坏死肌纤维中肌营养不良蛋白、α肌聚糖和α 1 syntrophin的免疫染色消失，几天后在再生肌纤维中重新出现。肌营养不良蛋白和α肌糖聚糖的表达倾向于在再生过程中较早出现。在多肌炎坏死或再生肌纤维中，肌层区肌营养不良蛋白和α肌聚糖免疫染色明显阳性，而α 1 syntrophin和NOS染色不佳或未染色细胞因子诱导C2C12骨骼肌肌细胞中NOS的表达：为了确定骨骼肌中是否可以诱导NOS的产生，我们用细胞因子刺激C2C12小鼠骨骼肌肌细胞。干扰素- γ、白细胞介素-1和肿瘤坏死因子- α的联合作用导致亚硝酸盐的产生。在细胞因子刺激下，细胞与L-NAME共孵育可显著减少亚硝酸盐的产生。Cu/Zn-SOD、Mn-SOD或过氧化氢酶共孵育也通过细胞因子刺激抑制亚硝酸盐的产生。少

[1] Histological determination of nitric oxide synthase (NOS) and superoxide dismutase (SOD) in biopsied human muscle : Immunohistochemical analyzes were made of Mn-SOD in biopsied muscles. Mn-SOD was mainly present in subsarcolmmal region of ragged-red fibers in mitochondrial encephalomyopathies. Mn-SOD positive fibers may be of use for diagnosing mitochondrial encephalomyopathies. In addition, to determine localization of nitric oxide synthase in diseased muscle, immunohistochemical analyzes of neuronal-type NOS (nNOS) and endothelial-type NOS (ec-NOS) were performed. Immunostaining of nNOS was prominent in the sarcolemmal region of the ragged-red fibers. Ec-NOS was strongly positive in the myofibrils of ragged-red fibers. Findings suggest that SOD and NOS are important in the muscles of patients with mitochondrial encephalomyopaties. In polymyositis, necrotic or regenerating fibers showed poorly staining of nNOS and NADH-diaphorase staining.[2] Histological localization of NOS and d … More ystrophin related proteins in necrotic or regenerating fibers in skeletal muscle : A rat model for necrosis or regeneration of skeletal muscle fibers was prepared by cardiotoxin injection in rat skeletal muscles. Immunostaining of dystrophin, alpha sarcoglycan and alpha 1 syntrophin disappeared in necrotic muscle fibers, and reappeared in regenerating fibers after several days. Expression of dystrophin and alpha sarcoglycan tended to be earlier than that of in the regenerating process. In necrotic or regenerating muscle fibers of polymyostitis, immunostaining of dystrophin and alpha sarcoglycan was distinctly positive in the sarcolemmal region, while alpha 1 syntrophin and NOS poorly stained or did not stain.[3] Cytokine-induced expression of NOS in C2C12 skeletal muscle myocytes : To determine whether NOS production can be induced in skeletal muscle, i stimulated C2C12 mouse skeletal muscle myocytes with cytokines. Combinations of interferon-gamma, interleukin-1alpha, and tumor necrotic facter-alpha resulted nitrite production. Nitrite production was significantly reduced by the coincubation of cells with L-NAME during cytokine stimulations. The coincubation Cu/Zn-SOD,Mn-SOD or catalase also inhibited nitrite production with cytokine stimulations. Less