一氧化氮和一氧化氮合酶的研究进展

自一氧化氮（ＮＯ）的生物学作用被揭示以来,每年均有大量关于ＮＯ或（和）一氧化氮合酶（ＮＯＳ）的研究报道,目前此项研究已扩展到全身各个系统。兹将ＮＯ和ＮＯＳ的一些基本问题、实验研究近况以及笔者的研究结果加以综述。１　ＮＯ生物作用的发现,ＮＯＳ的性质及Ｎ...     

噪声刺激对耳蜗一氧化氮合酶的影响

目的：探讨一氧化氮（ＮＯ）在噪声性聋发病中的作用。方法：用中高频连续稳态噪声制作噪声性聋的动物模型,用ＮＡＤＰＨ－黄递酶组织化学、原位杂效和Ｎｏｒｔｈｅｒｎ印迹法,观察噪声刺激对耳蜗一氧化氮合酶（ＮＯＳ）表达的影响。结果：组织化学法显示ＮＯＳ主要分布于内外毛细胞、螺旋神经节细胞和血管纹边缘细胞;原位杂效法发现ＮＯＳｍＲＮＡ在内外毛细胞、螺旋神经节细胞胞浆内均可见阳性染色,但血管纹边缘细胞无阳性染色     

一氧化氮及一氧化氮合酶与肿瘤血管形成的关系

肿瘤血管形成与肿瘤的发生发展密切相关。肿瘤血管生成受肿瘤周围微环境中多种调控因子的影响。近年来人们在对一氧化氮 (nitricoxide ,NO)与肿瘤生物学行为的研究中发现 ,NO及其限速酶一氧化氮合酶 (nitricoxidesynthase,NOS)在肿瘤血管生成过程中起着重要的作用。1　NO的产生NO是一种无机小分子 ,普遍存在于脊椎动物的各种细胞内。它是细胞间信息传递的重要调节因子 ,还可介导细胞免疫和细胞毒性反应。目前研究表明 ,NO可影响肿瘤的生长、分化、转移以及肿瘤血管生成。NO分子十分简单 ,但它的生物合成和代谢相当复杂。L 精氨酸 (L …     

一氧化氮在前庭学的研究进展

二十世纪末，一种小气体分子一氧化氮，引起医学界巨大的震动。尤其在神经科学领域，一氧化氮被作为一种新的气体型的神经递持被广泛研究，回顾和总结一氧化氮及一氧化氮合酶在前庭学的研究有助于对前庭生理，病理机制的探讨。     

一氧化氮及其合酶在鼻息肉中的表达

目的：探讨一氧化氮(NO)及其合酶(NOS)在鼻息肉中的表达，以及NO在鼻息肉发病中的作用。方法：用免疫组织化学及原位杂交方法研究诱导型一氧化氮合酶(iNOS)及内皮型一氧化氮合酶(eNOS)在鼻息肉中的表达，同时用原位杂交方法研究iNOS mRNA的表达，并用硝酸还原酶法研究NO在鼻息肉中的产生情况。结果：鼻息肉组织中eNOS主要分布于上皮、腺体细胞及血管内皮细胞，其染色强度稍强于对照组。iNOS在上皮细胞呈现较强的阳性染色，在息肉组织内主要表达于散在的炎症细胞。结论：eNOS活性增高可能与鼻息肉发病中血管过度扩张、腺体病理性分泌增多等有关。iNOS生成的较高浓度的NO在鼻息肉的病理过程中可能起到促进炎症发展的作用。     

一氧化氮-环磷酸鸟苷通路对耳蜗灵敏度的调节

目的探讨一氧化氮（NO，nitric oxide）-环磷酸鸟苷（cyclic guanosine monophosphate，cGMP）通路对耳蜗功能的调节。方法健康杂色豚鼠100只，雌雄不限，用随机数字表法随机分为10组，每组10只：①第1组：人工外淋巴液组；②第2组：L-精氨酸组；③第3组：Ca^2＋-ATP酶抑制剂组；④第4组：Ca^2＋-ATP酶抑制剂＋L-精氨酸组；⑤第5组：Ca^2＋-ATP酶抑制剂＋cGMP；⑥第6组：Ca^2＋-ATP酶抑制刺＋L．精氨酸＋非选择性一氧化氮合酶（NOS）抑制剂组；⑦第7组：血管内皮性一氧化氮合酶（eNOS）抑制剂组；⑧第8组：Ca^2＋-ATP酶抑制剂＋eNOS抑制剂组；⑨第9组：Ca^2＋-ATP酶抑制剂＋eNOS抑制剂＋L．精氨酸组；⑩第10组：Ca^2＋-ATP酶抑制剂＋eNOS抑制剂＋L-精氨酸＋神经元性一氧化氮合酶（nNOS）抑制剂组。分别全耳蜗灌流以上各组药物120min，由圆窗龛每隔30min测1次耳蜗微音器电位（cochlear microphonic，CM）和耳蜗听神经复合动作电位（compound action potential，CAP）。第3，4组灌流后留置标本做透射电镜的标本固定。结果第3组灌流Ca^2＋-ATP酶抑制刺前后CAP阈移为28．5dB，第4组在此基础上加入L．精氨酸可使CAP阈移改善9dB，且与加入cGMP后作用相似。第8组多加入eNOS抑制剂抑制血管纹功能后CAP阈移为42．5dB，再加入L-精氨酸可使CAP阈移改善7dB，而第10组加入nNOS抑制剂后CAP阈移较第9组增加了6、5dB，与第8组无明显差异。提示L-精氨酸在nNOS作用下可通过NO-cGMP通路来拮抗Ca^2＋-ATP酶抑制剂引起的胞内Ca^2＋-升高。透射电镜的结果显示：在Ca^2＋-ATP酶抑制剂的基础上加入L-精氨酸减轻了由Ca^2＋-ATP酶抑制剂所造成的外毛细胞的空泡化。结论NO-cGMP通路可调节耳蜗电位，L-精氨酸通过nNOS改善Corti器的功能。     

一氧化氮与头颈肿瘤

一氧化氮一方面介导了巨噬细胞、内皮细胞的杀瘤作用;另一方面,通过促进血管生成,增加血流量等促进肿瘤生长.对NO双向作用的深入研究.有助于探索头颈肿瘤发生、发展的机制和开辟治疗肿瘤的新途径.     

一氧化氮合酶在鼻生理和鼻疾病中的作用

一氧化氮合酶为催化一氧化氮生成的酶，参与机体组织的生理和病理过程，目前对其作用机制的研究已成为热点，本将对一氧化氮合酶在鼻生理和疾病过程中的作用综述如下。     

诱导型一氧化氮合酶mRNA在分泌性中耳炎中表达的意义

目的探讨分泌性中耳炎(secretory ototis media，SOM)患者中耳积液及外周血白细胞诱导型一氧化氮合酶(inducible nitric oxide synthase，iNOS)mRNA表达及在SOM发病过程中的意义，以及与细菌感染和免疫介导的关系。方法随机取45例SOM患者及30例健康人的外周血白细胞，并抽取SOM患者患耳中耳积液，用原位杂交方法检测iNOS—mRNA。结果健康人外周血白细胞未见iNOS—mRNA表达。SOM患者外周血白细胞iNOS—mRNA表达：急性组阳性率为63．64％，镜下阳性细胞率为60．3％；亚急性组阳性率为8．7％，镜下阳性细胞率为72．5％；SOM患者中耳积液iNOS—mRNA表达：急性组阳性率为45．45％，镜下阳性细胞率为80％；亚急性组阳性率为52．17％，镜下阳性细胞率为84％。SOM患者外周血白细胞及中耳积液中iNOS—mRNA表达高度增强，其中在急性组外周血白细胞中表达显著高于亚急性组，而中耳积液iNOS—mRNA表达阳性率及阳性细胞率在急性组与亚急性组中表达强度无显著性差异。结论诱导型一氧化氮合酶(iNOS)及诱导型一氧化氮合酶——氧化氮(iNOS—NO)通路在SOM的发病、中耳积液的形成过程中可能起着重要作用。     

鼻呼出气一氧化氮的检测及临床应用

一氧化氮（NO）是L-精氨酸被一氧化氮合成酶催化后所生成的产物,是气道炎症的标志物之一。鼻部NO（nNO）可构成鼻腔的防御屏障,保持鼻窦的相对无菌。临床上最常用的nNO检测方法是利用鼻塞式探头置于前鼻孔直接采集鼻呼出气。目前nNO已用于囊性纤维化及原发性纤毛运动障碍的筛查诊断,由于nNO与鼻窦窦口的阻塞程度等多种因素相关,动态监测治疗前后的nNO值及联合口呼出气一氧化氮（FeNO）检查对早期发现上下气道嗜酸粒细胞性炎症更有临床应用价值。     

鼻息肉中血管内皮生长因子mRNA的检测与意义

目的 :检测鼻息肉组织和鼾症下鼻甲粘膜组织中的血管内皮生长因子 (VEGF) m RN A水平的表达 ,了解其在慢性炎症过程中的作用。方法 :取 6例行下鼻甲切除术的下鼻甲粘膜和 7例鼻息肉切除术的鼻息肉标本 ,用半定量的反转录 -聚合酶链反应 (RT- PCR)方法检测 VEGF的 m RNA表达。结果 :RT- PCR结果显示在鼻息肉组织中 V EGF的表达较鼾症患者下鼻甲粘膜组织明显升高。结论 :鼻息肉组织中 VEGF的表达显著升高 ,推测 VEGF在鼻息肉的形成、生长及复发过程中具有极其重要的作用。     

鼻息肉中单核细胞趋化蛋白1和血管内皮生长因子的表达

目的明确单核细胞趋化蛋白1（monocyte chemotactic protein 1，MCP-1）和血管内皮生长因子（vascular endothelial growth factor，VEGF）在鼻息肉组织中的表达及其相关性，初步探讨MCP-1与鼻息肉发生的关系。方法取40例鼻息肉组织和25例下鼻甲组织，应用原位杂交和免疫组织化学等方法检测MCP-1和VEGF mRNA及蛋白质的表达。结果鼻息肉组织中MCP-1和VEGF mRNA及蛋白质的表达均高于对照组下鼻甲组织（P值均〈0．01）；鼻息肉组织中MCP-1和VEGF蛋白质的表达呈正相关（r=0．871，P〈0．05）。结论鼻息肉组织中MCP-1和VEGF表达增加，二者协同作用可能是鼻息肉形成的原因之一。     

Expression of inducible nitric oxide synthase in antrochoanal polyps

OBJECTIVE: Antrochoanal polyp (ACP) is a polypoid lesion originating from the maxillary sinus, emerging from the ostium and extending to the choana. Although the etiologic causes of ACP are not known completely, it presents a fairly uniform clinical appearance. Nitric oxide (NO) has an important role in non-specific immunoreactions and inflammation in various tissues and has a main regulatory role in airway function and seems to involve in pathomechanism of several respiratory system diseases. NO is synthesized by the effect of three isoforms of nitric oxide synthase i.e. inducible NOS (iNOS). Some studies revealed that ACP has some different characteristics from the ordinary nasal polyps. In the present study, in order to compare ACP with allergic and non-allergic nasal polyps (NANP), we detected and localized the iNOS expression and also evaluate some histological parameters. METHODS: Twenty-six cases were chosen from the files and four controls were used. The cases were separated as follows: normal inferior turbinate mucosa as control (n=4) ACPs (n=8), allergic nasal polyps (ANP) (n=9), and NANP (n=9). Five-micrometer thick sections were prepared from the paraffin sections of polyps and normal nasal mucosa to quantify the iNOS expression. iNOS protein was observed in the cytoplasm of epithelial and stromal inflammatory cells. iNOS protein expression in the groups was assessed according to the intensity of staining and histomorphological parameters, oedema, lymphocytic and eosinophilic cell infiltration were detected semi quantitatively. RESULTS: iNOS expressions, either stromal or epithelial, were not different from each other among the four groups. Although it is not statistically significant, we noted that ANP and ACP frequently showed moderate and severe iNOS protein expression in epithelial and stromal parts when compared with NANPs and controls. Also, iNOS expression was significantly higher in the stroma of the ANPs than NANPs (P=0.012). CONCLUSIONS: ACPs and ANPs have frequently showed moderate and significant epithelial and stromal iNOS expression. Further studies are needed in large groups to elucidate differences between ACP and the other nasal polyps.     

鼻息肉中一氧化氮合酶表达及其意义

目的 :了解鼻息肉 (NP)中一氧化氮合酶 (NOS)的分布特点和活性及其在NP发病中的作用。方法 :用免疫组织化学法检测 30例NP(NP组 )及 2 0例正常鼻黏膜 (正常鼻黏膜组 )中NOS的表达 ,并用分光光度计法检测其活性。结果 :NP组NOS活性为 (4.0 79± 0 .6 5 5 )U/mg蛋白 ,正常鼻黏膜组为 (1.5 2 6± 0 .310 )U/mg蛋白 ,二者间差异有统计学意义 (P <0 .0 1) ;NP组iNOS有大量细胞表达 ,分布在黏膜上皮、腺体和血管内皮细胞以及炎症细胞中 ,与正常鼻黏膜组比较 ,差异有统计学意义 (P <0 .0 1) ;而eNOS也有表达 ,但与正常鼻黏膜组比较 ,差异无统计学意义 ;NP组i NOS表达明显高于eNOS表达 ,其差异有统计学意义 (P <0 .0 1)。结论 :NP主要表达iNOS ,分布在黏膜上皮、腺体和血管内皮细胞以及炎症细胞中 ,其产生的大量一氧化氮在NP的发病过程中可能起着重要的作用     

Hypoxia effects on vascular endothelial growth factor derived epithelial cells of nasal polyps]

OBJECTIVE: To understand the role of nasal mucous epithelial cells to hypoxia in early stage of nasal polyps(NP) formation. METHODS: Epithelial cells of NP and inferior turbinate (IT) were cultured without serum under normal oxygen and hypoxia, and stimulus of inflammatory cytokines. Erythropoietin (EPO) was regarded as hypoxia mark, and expression of vascular endothelial growth factor(VEGF) mRNA and protein derived from epithelial cells were detected respectively by in situ hybridization and ELISA. RESULTS: 1. Under hypoxia, EPO mRNA was expressed intensely in epithelial cells from NP and IT, and there was no significant difference between both of them. This result suggested that EPO might be regarded as a hypoxic mark. 2. The ability of producing VEGF mRNA increased with cytokines stimulation, especially under hypoxia. Protein level of VEGF from epithelial cells of NP and IT increased with cytokines stimulation, especially in hypoxia and was time-dependent. CONCLUSION: Epithelial cells actively produce vast VEGF under hypoxia. The VEGF induced by hypoxia of the mucosa in middle meatus is of importance in the formation of nasal polyps(NP) in early stage, which may be the major cause of NP formation in middle meatus.     

鼻息肉组织嗜酸粒细胞中水通道蛋白-1和抗凋亡基因Bcl-2 mRNA的表达及意义

OBJECTIVE: To study the significance of aquaporin-1 (AQP-1) expression in the eosinophils of nasal polyps. The expression and location of AQP-1 mRNA and apoptosis associated gene Bcl-2 mRNA in nasal polyps were explored. METHODS: Sixteen nasal polyp samples were collected from 11 women and 5 men aged 20-65 years during routine endonasal surgery. Nasal mucosa specimens from the inferior turbinates of 10 patients with allergic rhinitis (7 women and 3 men, aged 16-58 years), collected during septoplasty, were used as controls. The expression of AQP-1 mRNA and Bcl-2 mRNA was detected in serial adjacent sections by in situ hybridization and eosinophils were examined by stain MGG. RESULTS: AQP-1 mRNA expression was found in all 16 nasal polyps and in 4 of 10 inferior turbinate tissues, the mean expression rates were (93.16 +/- 13.25)% and (19.54 +/- 4.98)%, respectively. All 16 nasal polyps and 10 control nasal tissues expressed Bcl-2 mRNA, by the average rates of (84.74 +/- 12.10)% and (16.45 +/- 3.12)%, respectively. The expression of AQP-1 mRNA was positively correlated with Bcl-2 mRNA expression in nasal polyps (r = 0.875, P < 0.01). CONCLUSIONS: AQP-1 contributes to the survival of eosinophils in nasal polyps by keeping the permeation balance of eosinophils.