吗啡依赖及戒断大鼠脊髓和脑干中一氧化氮合酶基因的表达

目的　观察吗啡依赖或吗啡戒断大鼠脊髓和脑干中一氧化氮合酶 (NOS)基因表达的变化。方法　以 β actin为内参照 ,用逆转录聚合酶链反应 (RT PCR)测定NOSmRNA的表达水平。结果　吗啡依赖大鼠脊髓和脑干NOS表达水平较正常对照大鼠降低 ,纳洛酮 ( 4mg·kg-1,ip)激发大鼠吗啡戒断症状 1h后脊髓和脑干中NOS表达水平明显升高 ,戒断 2h和 4h后NOS基因表达较 1h组减少。NOS抑制剂L N 硝基精氨酸甲酯 (L NAME ,10mg·kg-1)处理后大鼠吗啡戒断症状减少 ,同时脊髓和脑干的NOS基因表达水平较戒断 1h组明显降低。甲基东莨菪碱 ( 0 5mg·kg-1)处理组脊髓和脑干中NOS表达水平较戒断 1h组明显降低 ;选择性毒蕈碱受体M1拮抗剂 pirenzepine( 10mg·kg-1)处理组动物脊髓中NOS表达水平较戒断 1h组降低 ,而脑干中NOS表达水平没有改变 ;NMDA受体拮抗剂MK 80 1( 0 12 5mg·kg-1)处理后脊髓和脑干中NOS表达水平较戒断 1h组没有差异。结论　吗啡慢性处理后脊髓和脑干中NOSmR NA水平降低 ,抑制内源性NO生成和阻断毒蕈碱受体可以减少吗啡戒断所引起脊髓和脑干中NOS基因的表达     

脑复合剂对创伤性脑损伤模型大鼠脑内NO、nNOS活性及表达的影响

目的:探讨脑复合剂治疗对创伤性脑损伤(traumatic brain injury,TBI)模型大鼠脑保护作用可能的分子机制.方法:用自由落体打击(Feeney法)建立TBI模型,分别设立假手术组、TBI模型组及中药治疗组.中药治疗组给予脑复合剂10 g· kg-1·d-1,假手术组及TBI模型组给予同等剂量的等渗盐水...     

糖尿病心肌组织中NOS的改变与糖尿病心肌病关系探讨

目的探讨实验性糖尿病(DM)大鼠模型心肌组织中一氧化氮(NO)浓度和一氧化氮合酶(NOS)活性改变在DM心肌病发生和发展中的作用.方法SD大鼠一次注射链脲佐菌素(STZ)建立DM模型,成模后36只DM大鼠分批每两周检测空腹血糖和NO浓度,2、6、10周时进行心肌组织NOS活性检测.结果(1)DM大鼠血清中NO的浓度与对照组相比显著升高(P＜0.01),并随着血糖浓度的升高及时间的延长而升高.(2)DM组大鼠心肌组织NO浓度和NOS的活性均较对照组明显升高(P＜0.05).结论高血糖状态激活了心肌组织中的NOS,使心肌组织中NO过度增加,加上血液中过度升高的NO,损伤了心肌细胞的结构及其功能,可能是DM心肌病产生的重要机制之一.     

胃幽门螺杆菌与胃粘膜一氧化氮合酶表达的意义

目的探讨在胃癌发生过程中Hp感染与iNOS表达的关系及意义。方法采用快速尿素酶试验及Warthin-Starry银染色法检测入选病例的Hp,用免疫组织化学染色法检测iNOS。结果①在浅表性胃炎、胃溃疡、萎缩性胃炎及胃癌各组中Hp感染阳性率分别为55.2%、56.0%、43.5%、65.4%,各组间无显著性差异(P>0.05)。②iNOS表达在浅表性胃炎、胃溃疡、萎缩性胃炎和胃癌各组中阳性率分别为51.7%、52.0%、65.2%、80.8%,各组同浅表性胃炎比较:胃癌组有显著性差异(P<0.05),萎缩性胃炎组无显著性差异(P>0.05)。③Hp感染与iNOS表达的关系:各组慢性胃病中Hp感染阳性者iNOS表达率均显著高于非感染者(P<0.05)。④iNOS于胃癌中表达增强,在不同分化程度的胃癌中的表达无明显规律性。结论Hp可能参与慢性胃病的发生发展过程。iNOS高表达提示NO在炎症、溃疡乃至胃癌发生过程中有重要意义。     

神经元型一氧化氮合酶反义寡脱氧核苷酸抑制大鼠吗啡戒断症状

目的　观察鞘内或侧脑室注射神经元型一氧化氮合酶 (nNOS)反义寡脱氧核苷酸对大鼠吗啡戒断症状的影响。方法　根据基因结构设计nNOS或eNOS反义寡脱氧核苷酸片段 ,用逆转录聚合酶链反应 (RT PCR)测定nNOSmR NA表达。结果　吗啡依赖大鼠在纳洛酮激发前 2 4h鞘内注射nNOS反义寡脱氧核苷酸抑制所有大鼠吗啡戒断症状如湿狗摇动、扭体及激惹、腹泻、体重减少、咬牙和流涎。eNOS反义寡脱氧核苷酸对吗啡戒断症状总评分值没有影响 ,但减少腹泻、体重减轻值和咬牙等评分值。侧脑室注射nNOS反义寡脱氧核苷酸减少吗啡戒断症状 ,eNOS反义寡脱氧核苷酸对吗啡戒断症状没有影响。鞘内注射nNOS反义寡脱氧核苷酸后脊髓nNOSmRNA的相对表达几乎消失 ,iNOS的表达增加 ;而eNOS反义寡脱氧核苷酸处理后对nNOS和iNOS的表达没有影响。结论　nNOS基因表达介导了吗啡戒断反应过程 ,抑制nNOS基因表达可增加脊髓i NOS基因的表达。     

一氧化氮及一氧化氮合酶在成年与老年大鼠前列腺中的变化

目的:研究一氧化氮(NO)及一氧化氮合酶(NOS)在成年与老年大鼠前列腺中的变化,探讨在大鼠前列腺老年化过程中的临床意义。方法:取4月龄及20月龄SD雄性大鼠各6只,分别取前列腺组织匀浆,检测其NO与NOS活性。结果:老年组大鼠的NO与NOS活性明显低于成年组(P<0.05)。结论:老年大鼠前列腺组织中NO水平及NOS活性的降低可能与前列腺良性增生及功能减退有关。     

一氧化氮合成酶在周围神经中的表达

目的　研究一氧化氮合成酶在大鼠坐骨神经中的表达。方法　选用 SD大鼠 2 0只 ,其中 10只的坐骨神经用于 RT- PCR和 Western Blot的测定 ,另外 10只的坐骨神经用于免疫组织化学染色 ,通过这三种方法来观察一氧化氮合成酶是否在坐骨神经中存在以及它的分布状况。结果　经 RT- PCR获得 n NOS,e NOS和 i NOS。Western Blot显示在坐骨神经中一个 15 5 0 0 0的蛋白与大鼠脑的 n NOS阳性对照一起迁移 ,一个 140 0 0 0的蛋白与内皮细胞的 e NOS阳性对照一起迁移 ,而 i NOS未能检测。免疫组织化学染色显示在雪旺氏细胞和多数轴突中存在n NOS、e NOS只是位于坐骨神经上的血管内皮细胞中。神经中无 i NOS显色。结论　一氧化氮合成酶存在于正常大鼠的坐骨神经中 ,可能作为一种神经递质执行着重要的生物学功能。     

血清一氧化氮及一氧化氮合酶体系与轻度胃肠炎合并婴幼儿良性惊厥的相关性研究

目的探讨一氧化氮(NO)及一氧化氮合酶(NOS)体系在轻度胃肠炎合并婴幼儿良性惊厥(BICE)发病机制中的作用。方法收集2010年1月至2012年7月于山西省儿童医院诊治的BICE患儿40例、热性惊厥患儿26例、轮状病毒肠炎患儿14例及同期门诊体检的健康儿童30名,分别采用硝酸还原酶法、酶测定法检测血清中NO水平,总一氧化氮合酶(TNOS)水平及诱导型一氧化氮合酶(iNOS)水平。结果 BICE组患儿血清NO及iNOS水平明显高于健康儿童、热性惊厥组及轮状病毒肠炎组患儿(P<0.05),但TNOS水平各组间差异无统计学意义(P>0.05)。BICE严重组及普通组患儿血清NO水平差异无统计学意义(t=1.25,P>0.05),BICE轮状病毒阳性组与阴性组患儿血清中NO水平差异无统计学意义(t=1.12,P>0.05)。结论 iNOS增加而导致的NO水平升高,可能与BICE患者的发病有关。     

戊四唑癫痫大鼠脑组织一氧化氮含量和一氧化氮合酶活性变化

探讨一氧化氮在戊四唑癫病发机制中的作用。方法每天注射戊四唑建立在鼠癫痫模型,测定癫病发作后大鼠大脑皮质,海马一氧化氮和一氧化氮合酶活性变化,结果癫痫发作后海马ＮＯ含量和ＮＯＳ活性显著升高,结 戊四唑诱导的癫痫中具有致痫性。     

血浆一氧化氮、一氧化氮合酶和基质金属蛋白酶9在子宫颈癌中的临床意义

目的 探讨血浆一氧化氮（NO）、一氧化氮合酶（NOS）和基质金属蛋白酶（MMP-9）水平在子宫颈癌中的变化及临床意义.方法 经病理活检确诊为宫颈癌患者69例,分别于手术前1d、术后15 d、30 d空腹抽取外周静脉血,健康对照组取空腹静脉血,采用化学比色法和ELISA法分别测定血浆中NO、NOS和MMP-9含量,比较上述指标的变化及相关性.结果 宫颈癌患者血浆中NO、NOS、MMP-9的水平与健康对照组相比明显增高.宫颈癌患者手术前与手术后15 d、30 d NO水平比较,手术后NO、NOS、MMP-9的水平均明显降低,但仍明显高于对照组.宫颈癌患者有淋巴结转移者NO、NOS、MMP-9水平明显高于无淋巴结转移者;相关性分析表明,血清中MMP-9与NO、NOS呈明显正相关性.结论 检测血浆中NO、NOS和MMP-9水平的变化,对宫颈癌的病情判断及临床治疗指导具有参考意义.     

Identification and characterization of nitric oxide synthase inSalmonella typhimurium

The presence of the nitric oxide synthase (NOS) enzyme from Salmonella typhimurium (S. typhimurium) was identified by measuring radiolabeled L-[3H]citrulline and NO, and Western blot analysis. NOS was partially purified by both Mono Q ion exchange and Superose 12HR size exclusion column chromatography, sequentially. The molecular weight of NOS was estimated to be 93.3 kDa by Western blot analysis. The enzyme showed a significant dependency on the typical NOS cofactors; an apparent Km for L-arginine of 34.7 mM and maximum activity between 37 degrees C and 43 degrees C. The activity was inhibited by NOS inhibitors such as aminoguanidine and N(G),N(G)-dimethyl-L-arginine. Taken together, partially purified NOS in S. typhimurium is assumed to be a different isoform of mammalian NOSs.     

2,4,6-Trinitrotoluene inhibits endothelial nitric oxide synthase activity and elevates blood pressure in rats

2,4,6-Trinitrotoluene (TNT), which is widely used in explosives, is an important occupational and environmental pollutant. Human exposure to TNT has been reported to be associated with cardiovascular dysfunction, but the mechanism is not well understood. In this study, we examine the endothelial nitric oxide synthase (eNOS) activity and blood pressure value following TNT exposure. With a crude enzyme preparation, we found that TNT inhibited the enzyme activity of eNOS in a concentration-dependent manner (IC₅₀ value=49.4 μM). With an intraperitoneal administration of TNT (10 and 30 mg/kg) to rats, systolic blood pressure was significantly elevated 1 h after TNT exposure (1.2- and 1.3-fold of that of the control, respectively). Under the conditions, however, experiments with the inducible NOS inhibitor aminoguanidine revealed that an adaptive response against hypertension caused by TNT occurs. These results suggest that TNT is an environmental chemical that acts as an uncoupler of constitutive NOS isozymes, resulting in decreased nitric oxide formation associated with hypertension in rats.     

Associative learning is enhanced by selective neuronal nitric oxide synthase inhibitors and retarded by a nitric oxide donor in the rabbit

RATIONALE: Previous studies had reported that the nitric oxide (NO) donor, sodium nitroprusside (SNP), retarded and the non-specific NO synthase (NOS) inhibitor, Nomega-nitro-L-arginine methyl ester (L-NAME), enhanced acquisition of classically conditioned responses (CRs). These effects of IV SNP and IP L-NAME on CR acquisition occurred in the absence of any effect on non-associative processes or performance variables and at a time when there were no alterations in blood pressure or heart rate. OBJECTIVES: In this study, we examined whether the changes in associative learning produced by L-NAME and SNP were due to their central effects on NO content of brain. To this end, we examined the effects of the selective neuronal NOS inhibitors 7-nitroindazole (7-NI) and AR-R 17477 and the effects of central (ICV) administration of the NO donor SNP on learning. METHODS: Effects of drugs on CR acquisition were determined during classical conditioning of the rabbit's nictitating membrane (NM) response. Explicitly unpaired presentations of conditioned stimuli (CSs) and unconditioned stimuli (USs) were employed to measure non-associative levels of responding and unconditioned response (UR) topography. RESULTS: The SC injection of 7-NI and AR-R 17477 significantly enhanced associative learning while ICV administration of SNP significantly retarded learning. CONCLUSION: Production of NO within the brain by neuronal NOS normally acts to retard associative learning presumably by decreasing excitability within neuronal circuits involved in the acquisition of the classically conditioned NM reflex.     

Effect of nitric oxide synthase inhibitors on benzodiazepine withdrawal in mice and rats

This study was undertaken to evaluate the effect of nitric oxide (NO) synthase inhibitors on benzodiazepine withdrawal syndrome in mice and rats. Diazepam withdrawal in mice was read out as intensification of the seizures induced by a subthreshold dose of pentetrazole. In rats, the withdrawal syndrome resulting from chronic administration of diazepam, chlordiazepoxide, clonazepam and temazepam was characterized by audiogenic seizures, hypermotility and weight loss. Administration of the non-selective NO synthase inhibitors N(G)-nitro-L-arginine (L-NOARG) and N(G)-nitro-L-arginine methyl ester hydrochloride (L-NAME) significantly attenuated the withdrawal syndrome (i.e., pentetrazole-induced seizures) in diazepam-dependent mice. L-NOARG significantly suppressed hypermotility in clonazepam-dependent rats and inhibited the decrease in body weight observed after 12 h of withdrawal in chlordiazepoxide- and clonazepam-dependent rats. Moreover, a clear propensity of L-NOARG to protect benzodiazepine-dependent rats against audiogenic seizures was observed. These findings suggest that the cGMP/NO system may participate in causing the signs of benzodiazepine withdrawal.     

一氧化氮合成酶mRNA在正常大鼠肾组织中表达的研究

目的：探讨正常大鼠肾组织一氧化氮合成酶mRNA(NOSmRNA)表达的特点。方法 采用组织细胞原位杂交及图像分析技术,对正常大鼠肾组织中 NOS,NOSey NOSRNA表达的定位及含量进行了检测。同时测定肾组织NOS总活性。结果eNOS,nNOS及iNOS在正常肾组织中均有表达。eNOS和nNOS主要分布于肾小球及血管内皮,其中eNOS表达最丰富,髓质明显多于皮质。iNOS含量较低,且仅分布于皮质远,近曲小管上皮,结论 生理情况下,肾组织cNOS的表达量主要决定于eNOS的表达,其高表达对维持肾脏正常功能具有重要作用。     

Inhibition of neuronal nitric oxide synthase by antipsychotic drugs

There is rapidly accumulating evidence that generation of nitric oxide (NO) through a Ca²⁺ and calmodulin-dependent pathway plays various important roles in the central nervous system. In the present study, effects of several antipsychotics on the activity of NO synthase were investigated in rat cerebellum and neuroblastoma N1E-115 cells, due to the known ability of these agents to inhibit calmodulin. In cytosolic preparations of rat cerebellum, the antipsychotic drugs inhibited the conversion of [³H]l-arginine into [³H]l-citrulline by NO synthase in a concentration-dependent manner. This inhibition was noncompetitive in nature, and it exhibited an excellent correlation with blockade of calmodulin activity. Furthermore, these drugs attenuated cyclic GMP formation induced by a calcium ionophore in N1E-115 cells, a response which takes place as a consequence of NO generation. Taken together, our data demonstrate that antipsychotic drugs inhibit NO formation in vitro. It is unlikely, however, that these actions might contribute to their therapeutic and/or side effects, since they take place at relatively high concentrations.     

Cross talk between nitric oxide and ERK1/2 signaling pathway in the spinal cord mediates naloxone-precipitated withdrawal in morphine-dependent rats

Our recent study has shown activation of spinal extracellular signal-regulated kinase-1 and -2 (ERK1/2), a member of the mitogen-activated protein kinase (MAPK) family, contributes to naloxone-precipitated withdrawal and withdrawal-induced spinal neuronal sensitization in morphine-dependent rats. However, the mechanism and significance of the spinal ERK1/2 activation during morphine dependence and withdrawal remain unknown. In this study, we reported that intrathecal (i.t.) pretreatment with either the non-selective nitric oxide synthase (NOS) inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME), neuronal NOS (nNOS) inhibitor 7-nitro indazole (7-NI), or the inducible NOS (iNOS) inhibitor aminoguanidine (AG), could reduce morphine withdrawal-induced increase of phospho-ERK1/2 (pERK1/2) expression in the rat spinal cord. On the other hand, attenuation of the spinal ERK phosphorylation by the MAPK kinase (MEK) inhibitor U0126 also could inhibit the increase of nNOS and iNOS expression in the spinal cord of morphine withdrawal rats. Inhibitory expression of pERK1/2 by i.t. NOS inhibitor L-NAME, 7-NI or AG and of nNOS and iNOS by i.t. U0126 in the spinal cord were accompanied by decreased scores of morphine withdrawal and the inhibited spinal Fos protein (a maker for neuronal excitation or activation) expression induced by morphine withdrawal. These findings suggest cross talk between nitric oxide (NO) and the ERK1/2 signaling pathway mediates morphine withdrawal and withdrawal-induced spinal neuronal sensitization in morphine-dependent rats.     

Peristalsis in the isolated guinea-pig ileum during opiate withdrawal

Summary Naloxone enhances peristalsis in isolated intestinal segments from morphine-dependent guinea-pigs to a greater degree than in naive preparations. These data suggest that a peripheral mechanism may be involved in the expression of opiate withdrawal in the small intestine, and indicate that the action of this mechanism leads, at least in vitro, to an increase in the number of peristaltic waves.     

Effects of water deprivation and angiotensin II intracerebroventricular administration on brain nitric oxide synthase activity

Intracranial administration of -arginine causes a reduction of the water intake induced by water deprivation or by intracerebroventricular (i.c.v.) injection of angiotensin II (angiotensin II), through the release of nitric oxide (NO) in the central nervous system. We studied the effects of i.c.v. angiotensin II (120 ng/rat) in association with i.c.v. -arginine (2.5–10 μg/rat) on blood pressure. We also studied the effects of both peripheral and central angiotensin II injection (1.5–6 mg kg⁻¹ i.p. and 30–120 ng rat⁻¹ i.c.v., respectively) on NO synthase activity in the cortex, diencephalon and brainstem, after water deprivation (24 h), conditions producing activation of the renin-angiotensin system. -arginine dose dependently antagonized the increase in blood pressure induced by i.c.v. angiotensin II (P<0.001). Peripheral administration of angiotensin II produced a dose-dependent reduction of NO synthase activity in the brainstem and cortex (P<0.001), but not in the diencephalon. Water deprivation produced similar effects on brain NO synthase activity. Angiotensin II i.c.v. injection caused NO synthase activity reduction in all brain regions studied (P<0.001). Our findings suggest that NO and angiotensin II could play opposite roles in brain regulation of blood pressure and drinking behaviour.     

Role of sodium cromoglycate on analgesia,locomotor activity and opiate withdrawal in mice

The role of sodium cromoglycate (CRO) on analgesia, locomotor activity and morphine withdrawal in mice was studied in morphine-dependent and drugnaive mice. CRO (0.5, 1, 5, 10, 30, 50 and 100 mg/kg, SC) induces analgesia (hot plate), an effect blocked by previous administration of the opiate antagonist naloxone (1 mg/kg). Furthermore, CRO (30 mg/kg) potentiates morphine analgesia. In morphine-tolerant mice, moderate doses of CRO (0.5, 1, 5, 10 and 30 mg/kg) do not induce analgesia, which suggested the development of cross tolerance between CRO and morphine, whereas coadministration of CRO and morphine in morphine tolerant animals restored the sensitivity to morphine. Administration of CRO (10 and 30 mg/kg) induces an increase in spontaneous locomotor activity, and previous administration of naloxone (1 mg/kg) blocks this effect, whereas CRO (10 mg/kg) blocks morphine (10 mg/kg) and amphetamine (3 mg/kg)-induced hyperactivity. CRO (10, 50 and 100 mg/kg) induces a significant and dose-dependent reduction in the number of jumps (jumping up) during naloxone (1 mg/kg)-induced withdrawal in morphine-dependent mice. Finally, CRO (100 mg/kg) reduces the wet dog shake phenomenom during naloxone-induced withdrawal in morphine-dependent mice. These results suggest a possible stabilizing effect of CRO on the membranes of neurones that mediate analgesia, locomotor activity and opiate abstinence. Changes and inhibition of DA, NA and 5-HT release may also explain these effects.This work was supported by a grant from the CICYT (Program FAR 90/0543).