Anticonvulsive effect of atorvastatin on pentylenetetrazole‐induced seizures in mice: the role of nitric oxide pathway

Atorvastatin has shown to possess neuroprotective, antiexcitotoxic, and antiepileptic effects besides its cholesterol‐lowering properties. Nitric oxide (NO) may be responsible for a group of these effects. In the present study, a model of clonic seizure induced by pentylenetetrazole (PTZ) in male NMRI mice was used to investigate the anticonvulsive effects of atorvastatin through NO‐dependent pathways. Atorvastatin (5 mg/kg) significantly increased the seizure threshold (P < 0.001). Moreover, L‐arginine (a precursor of NO) significantly (P < 0.01) potentiated the anticonvulsive effects of subeffective doses of atorvastatin (1 mg/kg). Finally, L‐NAME [L‐arginine methyl ester dihydrochloride], a nonspecific NO synthase inhibitor, completely abolished the anticonvulsive properties of atorvastatin. Our findings demonstrated the role of atorvastatin as an anticonvulsive agent and showed the effects to be mediated through NO‐related pathways.     

The effect of sumatriptan on nitric oxide synthase enzyme production after iatrogenic inflammation in the brain stem of adolescent rats: A randomized, controlled, experimental study

Background: Migraine is a common disabling disorder of childhood and adolescence. Despite advances in the understanding of migraine pathophysiology, treatment remains a challenge.Objectives: The aims of this study were to investigate the production of nitric oxide synthase (NOS) enzymes in the brain stem of adolescent rats, using an experimental model of migraine, and the effect of sumatriptan pretreatment on the production of the NOS enzymes.Methods: Male adolescent (aged ~2 months) Wistar rats were used in the study. The animals were anesthetized using pentobarbital. The trigeminovascular system was stimulated by injecting a proinflammatory molecule, carrageenan, into the cis-terna magna of the anesthetized rats. The animals were divided into 3 groups of equal size: (1) the study group, in which the rats were treated with sumatriptan succinate 2 hours before intracisternal carrageenan injection; (2) the sham group, in which the rats were not administered intracisternal carrageenan injection or sumatriptan pretreatment; and (3) the control group, in which the rats were administered intracisternal carrageenan injection but were not pretreated with sumatriptan. In the control and study groups, the rats were euthanized using ether anesthesia 1 hour after intracisternal carrageenan injection. Rats in the sham group were euthanized 1 hour after intracisternal catheterization. Brain tissue was removed and endothelial NOS (eNOS), neuronal NOS (nNOS), and inducible NOS (iNOS) immunohistochemistry was performed.Results: Twenty-one rats were randomized into 3 groups of 7. The mean values of the immunolabeling intensities for eNOS, nNOS, and iNOS enzymes in the brain stem were significantly lower in the sham group compared with the control group (P = 0.001, P = 0.002, and P = 0.001, respectively). The mean values of the immunolabeling intensities of eNOS, nNOS, and iNOS in the brain stem were significantly lower in the study group compared with the control group (P = 0.001, P = 0.025, and P = 0.005, respectively).Conclusions: In this experimental model of migraine in adolescent rats, intracisternal injection of carrageenan was associated with a significant increase in the production of NOS enzymes in the brain stem. Pretreatment with sumatriptan was associated with a decrease in NOS production.     

Low‐intensity ultrasound increases endothelial cell nitric oxide synthase activity and nitric oxide synthesis

Summary. Low‐intensity ultrasound (US) increases tissue perfusion in ischemic muscle through a nitric oxide (NO)‐dependent mechanism. We have developed a model to expose endothelial cells to well‐characterized acoustic fields in vitro and investigate the physical and biological mechanisms involved. Human umbilical vein endothelial cells (HUVEC) or bovine aortic endothelial cells (BAEC) were grown in tissue culture plates suspended in a temperature‐controlled water bath and exposed to US. Exposure to 27 kHz continuous wave US at 0.25 W cm^?2 for 10 min increased HUVEC media NO by 102 ± 19% (P < 0.05) and BAEC by 117 ± 23% (P < 0.01). Endothelial cell NO synthase activity increased by 27 ± 24% in HUVEC and by 32 ± 16% in BAEC (P < 0.05 for each). The cell response was rapid with a significant increase in NO synthesis by 10 s and a maximum increase after exposure for 1 min. By 30 min post‐exposure NO synthesis declined to baseline, indicating that the response was transient. Unexpectedly, pulsing at a 10% duty cycle resulted in a 46% increase in NO synthesis over the response seen with continuous wave US, resulting in an increase of 147 ± 18%. Cells responded to very low intensity US, with a significant increase at 0.075 W cm^?2 (P < 0.01) and a maximum response at 0.125 W cm^?2. US caused minor reversible changes in cell morphology but did not alter proliferative capacity, indicating absence of injury. We conclude that exposure of endothelial cells to low‐intensity, low‐frequency US increases NO synthase activity and NO production, which could be used to induce vasodilatation experimentally or therapeutically.     

Wine polyphenols modulate calcium handling in rat aorta: involvement of nitric oxide pathway

The effects of short-term oral administration of red wine polyphenolic compounds (RWPCs) on blood pressure and vascular reactivity were investigated in rats. The consequence of RWPCs treatment on agonist-induced contractility of rat aorta with respect to Ca2+ handling was assessed, by examining both intracellular Ca2+ store and extracellular Ca2+ influx components of the response. Rats were treated daily for 7 days by intragastric administration of either 5% glucose, or RWPCs (20 mg/kg) [from two different sources, i.e. Provinols (SFD, Vallont Pont d'Arc, France) and RWPC1 (INRA, Montpellier, France)]. Administration of these compounds produced a decrease in systolic blood pressure. The consequence of RWPCs treatment on vascular smooth muscle was investigated in rat aorta without endothelium exposed to noradrenaline. In Ca(2+)-free medium, RWPC1 but not Provinols treatment induced an increase in noradrenaline-induced contraction. After depletion of intracellular Ca2+ stores by noradrenaline in Ca(2+)-free medium, addition of CaCl2 in the continuous presence of agonist induced an increase in contraction, which was not significantly different between control, Provinols- and RWPC-treated rats. The presence of an inhibitor of sarcoplasmic reticulum Ca(2+)-ATPase, thapsigargin, significantly reduced noradrenaline-induced contraction in Ca(2+)-free medium in RWPCs-treated aorta, as compared to that of control. Interestingly, the inhibitory effect of thapsigargin on the response linked to the release of Ca2+ from internal stores in RWPCs-treated vessels was completely prevented in the presence of NO-synthase inhibitor, L-nitro arginine methyl ester, the inhibitor of guanylyl cyclase, oxadiazolo-quinoxaline or the protein kinase G inhibitor, 8-Bromoguanosine-3'-5-cyclic mono-phosphorothioate, Rp isomer. These results suggest that short-term administration of RWPCs in rats induced subtle alteration of thapsigargin-sensitive component of agonist-induced contraction in rat aorta linked to Ca2+ release from intracellular store. Calcium release from intracellular stores sensitive to thapsigargin was implicated in this mechanism. The prevention of the inhibitory effect of thapsigargin by the inhibitors of NO/cyclic guanosine monophosphate pathway after RWPCs treatment highlights the role of NO in this phenomenon.     

Effects of nitric oxide synthase inhibitors 1‐(2‐trifluoromethylphenyl) – imidazole (TRIM) and 7‐nitroindazole (7‐NI) on learning and memory in mice

Nitric oxide (NO) plays an important role in hippocampal long‐term potentiation (LTP), which is involved in memory processes. This led to the hypothesis that nitric oxide synthase (NOS) inhibitors will have disturbing effects on learning and memory. The aim of our study was to investigate the effects of the new selective neuronal and inducible NOS inhibitor 1‐ (2‐trifluoromethylphenyl) imidazole (TRIM) (10–50 mg/kg) on learning and memory and compare it to the nonselective NOS inhibitor 7‐NI (15–45 mg/kg) using different behavioral tests in Swiss mice, thus clarifying the role of neuronal NOS (nNOS) and endothelial NOS (eNOS) in cognitive processes. TRIM had no specific effect on either learning or memory parameters, while 7‐NI (30 mg/kg) disturbed spatial memory in the probe trial of the Morris water maze test, which was performed on the last day of the test. No differences between TRIM and the control groups were observed, while 7‐NI (30 and 45 mg/kg) significantly disturbed memory in the novel object recognition test. In the social transmission of food preference test, both TRIM (50 mg/kg) and 7‐NI (45 mg/kg) impaired hippocampal olfactory memory, but the total food consumption was also significantly decreased at these doses. In the passive avoidance test, TRIM did not disturb the performance, while memory impairment was observed, even with lower doses of 7‐NI. All of these results suggest that TRIM has no clear effect on cognitive impairment compared to 7‐NI and that inhibition of both nNOS and eNOS are necessary for the deterioration of memory processes.     

Nitric oxide‐sensitive guanylyl cyclase is the only nitric oxide receptor mediating platelet inhibition

See also Gordge MP. Nitric oxide: a one‐trick pony? This issue, pp 1340–2. Summary. Background: The nitric oxide (NO)/cyclic guanosine monophosphate (cGMP) signaling cascade is involved in the precise regulation of platelet responses. NO released from the endothelium is known to activate NO‐sensitive guanylyl cyclase (NO‐GC) in platelets. By the generation of cGMP and subsequent activation of cGMP‐dependent protein kinase (PKG), NO‐GC mediates the reduction of the intracellular calcium and inhibits platelet adhesion and aggregation. However, NO has been postulated to influence these platelet functions also via cGMP‐independent mechanisms. Objective: We studied the effect of NO on platelets lacking NO‐sensitive guanylyl cyclase with regards to aggregation, adhesion, calcium mobilization and bleeding time. Methods and results: Here, we show that NO signaling leading to inhibition of agonist‐induced platelet aggregation is totally abrogated in platelets from mice deficient in NO‐GC (GCKO). Even at millimolar concentrations none of the several different NO donors inhibited collagen‐induced aggregation of GCKO platelets. In addition, NO neither affected adenosine 5′‐diphosphate (ADP)‐induced adhesion nor thrombin‐induced calcium release in GCKO platelets. Although the NO‐induced cGMP signal transduction was totally abrogated cyclic adenosine monophosphate (cAMP) signaling was still functional; however, cGMP/cAMP crosstalk was disturbed on the level of phosphodiesterase type 3 (PDE3). These in vitro data are completed by a reduced bleeding time indicating the lack of NO effect in vivo. Conclusions: We conclude that NO‐GC is the only NO receptor in murine platelets mediating the inhibition of calcium release, adhesion and aggregation: lack of the enzyme leads to disturbance of primary hemostasis.     

Headache induced by a nitric oxide donor (nitroglycerin) responds to sumatriptan. A human model for development of migraine drugs

Experimental "vascular" headache in humans may be used in characterizing new migraine drugs. The effects of sumatriptan on nitroglycerin-(NTG)-induced headache and arterial responses were therefore studied. Following a double-blind randomized crossover design, 10 healthy volunteers received sumatriptan 6 mg s.c. or placebo succeeded by 20 min NTG (0.12 mg/kg/min) infusion. Headache was rated on a 10 points scale. Temporal and radial artery diameters and velocity in the middle cerebral artery (MCA) were measured with ultrasound. Sumatriptan reduced the NTG-induced headache, median score 1.5 versus 4 after placebo ( p <0.01) and decreased temporal and radial artery diameters 75±3 and 86±3% of baseline respectively ( p <0.05), Blood velocity in the MCA was unaffected. The NTG model may prove to be a valuable tool in the development of future migraine drugs. The results suggest that NTG headache in non-migraineurs may share mechanisms with migraine headache.     

Exhaled nitric oxide and its long‐term variation in healthy non‐smoking subjects

Exhaled nitric oxide (NOexp) is an indicator of inflammation in the airways. Reference values obtained from healthy adults or information on long‐term variation of NOexp are not yet available. The aims of this pilot study were to collect values of NOexp from a selected group of healthy adults and to assess their long‐term variation. We studied 26 healthy subjects (age 21–48, 16 male, 10 female) with normal findings in flow‐volume spirometry, pulmonary diffusing capacity, relative amount of blood eosinophils, chest X‐ray and ECG at rest. NOexp was determined according to the European Respiratory Society guidelines during slow expiration against an airflow resistance. The measurements were repeated after 7 (n=13) and 23 days (n=17). The mean value of NOexp (n=26) was 6·9 ng g^–1 (95% confidence interval, 6·0–7·9 ng g^–1). The upper limit of intra‐individual variation (+2 SD) was 11·9 ng g^–1 and the lower limit (–2 SD) 1·9 ng g^–1, respectively. The mean (SD) value of NO production (NO output) was 39·1 pmol s^–1 (20 pmol s^–1). We found no correlation between NOexp and age (r=–0·06, P=0·78) and no association of NOexp with the gender (male vs. female, P=0·40). The intraindividual coefficient of variation (CoV) was 15·8% of NOexp and 20·7% of NO output within the interval of 7 days. CoV was 16·8% of NOexp and 18% of NO output within the interval 23 days. The results suggest that NOexp values over 12 ng g^–1 are abnormally high in healthy subjects. According to the results the change of NOexp by 30–35% or more within the interval of 1–3 weeks would be abnormal.     

5‐HT3 receptors antagonists reduce serotonin‐induced scratching in mice

Serotonin (5‐hydroxytryptamine, 5‐HT) acts as a pruritogen in humans and animals, but the mechanisms of action through that serotonin induces itch response have not been extensively discovered. In our study, we attempted to investigate the role of 5‐HT3 receptors in scratching behavior due to intradermal serotonin injection. Intradermal injection of serotonin (14.1–235 nmol/site) into the nape of the neck of mice was performed to elicit itch. Scratching behavior was evaluated by measuring the number of bouts during 60 min after injection. We evaluated the effect of intraperitoneal pretreatment with ondansetron and tropisetron (0.1, 0.3, and 1 mg/kg) on itch induced by serotonin. Also, intradermal ondansetron and tropisetron at doses 50, 100, and 200 nmol/site were concurrently administrated with serotonin. Serotonin produced a significant enhancement in scratching at dose 141 nmol/site. Concurrent administration of ondansetron (50, 100, and 200 nmol/site) and tropisetron (100 and 200 nmol/site) with serotonin reduced scratching activity compared to the animals that only received serotonin. Also, pretreatment with intraperitoneal ondansetron and tropisetron (0.3 and 1 mg/kg) 30 min before serotonin attenuated the itch response. We showed that the scratching induced by intradermal serotonin is mediated by 5‐HT3 receptors subtype. It can be concluded that 5‐HT3 may play a role in mediating serotonin‐associated itch responses, and we introduce 5‐HT3 receptors as possible targets for antipruritic agents.     

Pharmacological evidence for the involvement of the NMDA receptor and nitric oxide pathway in the antidepressant-like effect of lamotrigine in the mouse forced swimming test

Lamotrigine is an anticonvulsant agent that shows clinical antidepressant properties. The aim of the present study was to investigate the involvement of N-methyl-d-aspartate (NMDA) receptors and nitric oxide-cyclic guanosine monophosphate (NO-cGMP) synthesis in possible antidepressant-like effect of lamotrigine in forced swimming test (FST) in mice. Intraperitoneal administration of lamotrigine (10 mg/kg) decreased the immobility time in the FST (P < 0.01) without any effect on locomotor activity in the open-field test (OFT), while higher dose of lamotrigine (30 mg/kg) reduced the immobility time in the FST (P < 0.001) as well as the number of crossings in the OFT. Pretreatment of animals with NMDA (75 mg/kg), l-arginine (750 mg/kg, a substrate for nitric oxide synthase [NOS]) or sildenafil (5 mg/kg, a phosphodiesterase [PDE] 5 inhibitor) reversed the antidepressant-like effect of lamotrigine (10 mg/kg) in the FST. Injection of l-nitroarginine methyl ester (l-NAME, 10 mg/kg, a non-specific NOS inhibitor), 7-nitroindazole (30 mg/kg, a neuronal NOS inhibitor), methylene blue (20 mg/kg, an inhibitor of both NOS and soluble guanylate cyclase [sGC]), or MK-801 (0.05 mg/kg), ketamine (1 mg/kg), and magnesium sulfate (10 mg/kg) as NMDA receptor antagonists in combination with a sub-effective dose of lamotrigine (5 mg/kg) diminished the immobility time of animals in the FST compared with either drug alone. None of the drugs produced significant effects on the locomotor activity in the OFT. Based on our findings, it is suggested that the antidepressant-like effect of lamotrigine might mediated through inhibition of either NMDA receptors or NO-cGMP synthesis.     

Pharmacological mechanisms involved in the antinociceptive effects of dexmedetomidine in mice

Dexmedetomidine (DEX) is a α₂‐adrenoceptor (α₂‐AR) agonist used as an anesthetic adjuvant and as sedative in critical care settings. Typically, α₂‐AR agonists release nitric oxide (NO) and subsequently activate NO‐GMPc pathway and have been implicated with antinociception. In this study, we investigate the pharmacological mechanisms involved in the antinociceptive effects of DEX, using an acetic acid‐induced writhing assay in mice. Saline or DEX (1, 2, 5, or 10 μg/kg) was intravenously injected 5 min before ip administration of acetic acid and the resulting abdominal constrictions were then counted for 10 min. To investigate the possible mechanisms related to antinociceptive effect of DEX (10 μg/kg), the animals were also pretreated with one of the following drugs: 7‐nitroindazole (7‐NI; 30 mg/kg ip); 1H‐[1,2,4] oxadiazole [4,3‐a] quinoxaline‐1‐one (ODQ; 2.5 mg/kg, ip); yohimbine (YOH; 1 mg/kg, ip); atropine (ATRO; 2 mg/kg, ip); glibenclamide (GLIB; 1 mg/kg, i.p.) and naloxone (NAL; 0.2 mg/kg, ip). A rotarod and open‐field performance test were performed with DEX at 10 μg/kg dose. DEX demonstrated its potent antinociceptive effect in a dose‐dependent manner. The pretreatment with 7‐NI, ODQ, GLIB, ATRO, and YOH significantly reduced the antinociceptive affects of DEX. However, NAL showed no effecting DEX‐induced antinociception. The rotarod and open‐field tests confirmed there is no detectable sedation or even significant motor impairment with DEX at 10 μg/kg dose. Our results suggest that the α₂‐AR and NO‐GMPc pathways play important roles in the systemic antinociceptive effect of DEX in a murine model of inflammatory pain. Furthermore, the antinociceptive effect exerted by DEX appears to be dependent on K_ATP channels, independent of opioid receptor activity.     

辛伐他汀纳米粒通过调节诱导型一氧化氮合酶/内皮型一氧化氮合酶系统对小鼠脓毒症相关急性肺损伤的影响

目的探讨辛伐他汀纳米粒对脓毒症相关急性肺损伤小鼠肺组织中诱导型一氧化氮合酶（iNOS）/内皮型一氧化氮合酶（eNOS）平衡的调节以及对脓毒症小鼠预后的影响。 方法将90只C57 / BL6小鼠分为假手术组、脓毒症组、灌胃组、静脉制剂组及纳米粒组,每组各18只。采用盲肠结扎穿孔术（CLP）建立脓毒症小鼠模型;灌胃组小鼠通过灌胃针,给予辛伐他汀口服制剂灌胃治疗后进行CLP术;静脉制剂组及纳米粒制剂组小鼠CLP术后,立即分别通过尾静脉注射预配置好的辛伐他汀静脉制剂和辛伐他汀纳米粒制剂。其中每组12只小鼠用于7 d生存评估,另外6只用于24 h时间点标本采集。每24小时观察小鼠的生存情况,然后记算各组小鼠每日生存情况。采用苏木素-伊红（HE）染色观察5组小鼠病理变化并计算肺损伤病理评分,免疫组织化学法检测5组小鼠肺组织iNOS、eNOS表达水平。 结果Kaplan-Meier生存曲线结果显示,5组小鼠7 d生存情况比较,差异有统计学意义（χ² = 3.780,P < 0.001）。进一步两两比较发现,脓毒症组及灌胃组小鼠的7 d生存情况均较假手术组明显下降（P均< 0.001）,而纳米粒组小鼠的7 d生存情况显著优于脓毒症组（P = 0.001）。HE染色结果显示,假手术组小鼠肺组织未见明显病理征象;脓毒症组小鼠肺组织弥漫性中性粒细胞浸润、肺泡腔变小、肺泡间中隔增厚、肺间质弥漫性水肿、细胞排列紊乱、部分肺组织完整性遭破坏;灌胃组小鼠病理所示与脓毒症组相似;静脉制剂组及纳米粒组小鼠中性粒细胞渗出均较脓毒症组损伤减少、肺泡完整性较好、损伤程度较轻。5组小鼠肺损伤病理评分、iNOS及eNOS表达水平比较,差异均有统计学意义（F = 889.200、9.633、6.918,P均< 0.05）。进一步两两比较发现,脓毒症组小鼠的肺损伤病理评分、iNOS及eNOS表达水平与假手术组比较,差异均有统计学意义（P均< 0.05）;静脉制剂组及纳米粒组小鼠病理评分、iNOS及eNOS表达水平与脓毒症组比较,差异均有统计学意义（P均< 0.05）,且纳米粒组小鼠的肺损伤病理评分较静脉制剂组显著降低（P < 0.05）。 结论不同的辛伐他汀制剂具有不同的效应,其中纳米粒制剂对于脓毒症相关的肺损伤最具保护价值,建立eNOS与iNOS之间的平衡,可以成为具有保护效应的重要处理位点。     

雾化吸入氯胺酮对哮喘大鼠肺组织一氧化氮及一氧化氮合酶的影响

目的通过建立大鼠支气管哮喘模型,观察不同浓度氯胺酮对哮喘大鼠肺组织iNOS活性及NO含量的影响。方法SD大鼠随机分成对照组(N组)、哮喘模型组(A组)、不同浓度氯胺酮预处理组(分别为K1组、K2组)和地塞米松组(D组),每组8只。A组大鼠用卵白蛋白辅以百日咳杆菌菌苗和氢氧化铝为佐剂注射致敏,2周后雾化吸入卵蛋白激发哮喘;氯胺酮处理组大鼠用同样方法致敏,但在激发前分别给予雾化吸入氯胺酮25 g/L(K1组)和50 g/L(K2组);D组在激发前给予雾化吸入0.01%地塞米松;N组用生理盐水替代卵蛋白进行注射和吸入。每组分别测定其肺组织NO2-/NO3-水平、肺组织诱导型NOS(iNOS)和原生型NOS(cNOS)活性水平,并用免疫组织化学法观察iNOS在大鼠哮喘模型肺组织中的分布。结果A组肺组织中NO2-/NO3-和iNOS水平升高,iNOS和肺组织NO2-/NO3-水平呈高度正相关;K1、K2组肺组织中NO2-/NO3-和iNOS水平低于A组(P<0.05);D组肺组织中NO2-/NO3-和iNOS水平亦低于A组(P<0.05)。结论25 g/L或50 g/L的氯胺酮雾化吸入可抑制哮喘大鼠肺组织iNOS活性,降低NO含量,减轻大鼠肺部炎症。     

生脉饮对内毒素诱导急性肺损伤大鼠一氧化氮及其合酶的影响

目的:探讨一氧化氮(NO)和诱生型一氧化氮合酶(iNO S)在脂多糖(LPS)诱导大鼠急性肺损伤(AL I)中的作用及生脉饮对其的影响。方法:雄性W istar大鼠按随机数字表法分为对照组、AL I组、生脉饮组、地塞米松组。舌下静脉注射LPS复制AL I模型。观察大体标本、组织病理以及肺湿/干重比、支气管肺泡灌洗液中中性粒细胞比、蛋白含量、肺毛细血管通透性和肺泡通透性指数等生物学指标。测定血浆NO和肺组织匀浆iNO S活性。结果:与对照组比较,AL I组肺组织病理显示肺间质及肺泡有明显的损伤和细胞浸润,各生物学指标及NO和iNO S显著升高(P<0.05或P<0.01);与AL I组比较,地塞米松组和生脉饮组肺组织病理明显减轻,各生物学指标及NO、iNO S也相应下降(P<0.05或P<0.01)。结论:地塞米松和生脉饮两种药物对LPS诱导的AL I具有保护作用,其机制可能是通过抑制NO水平和iNO S活性实现。     

Further analysis of acute antinociceptive and anti‐inflammatory actions of 4‐phenylselenyl‐7‐chloroquinoline in mice

A new quinoline containing selenium, 4‐phenylselenyl‐7‐chloroquinoline (4‐PSQ), was described and synthetized by our research group. Recently, we demonstrated the potential antinociceptive and anti‐inflammatory of 4‐PSQ. For this reason, the first objective of this study was to expand our previous findings by investigating the contribution of glutamatergic, serotonergic, and nitrergic systems to the acute antinociceptive action of this compound. Pretreatment with 4‐PSQ (0.01–25 mg/kg, p.o.) reduced the nociception induced by glutamate. MK‐801 (an uncompetitive antagonist of the N‐Methyl‐d ‐aspartate (NMDA) receptor) blocked the antinociceptive effect exerted by 4‐PSQ (25 mg/kg, p.o.) in the acetic acid‐induced abdominal writhing test. The pretreatment with WAY100635 (a selective antagonist of 5‐HT_1A receptor), ketanserin (a selective antagonist of 5‐HT_2A/2C receptor), and pindolol (a nonselective antagonist of 5‐HT_1A/1B receptors) partially blocked the antinociceptive effect caused by 4‐PSQ (25 mg/kg, per oral, p.o.) in the acetic acid‐induced abdominal writhing test. Nitric oxide precursor, l ‐arginine hydrochloride, partially reversed antinociception caused by 4‐PSQ or ω‐nitro‐l ‐arginine (l ‐NOARG). Treatments did not modify the locomotor and exploratory activities of mice. Additionally, the acute anti‐inflammatory effect of 4‐PSQ in a model of pleurisy induced by carrageenan in mice was investigated. 4‐PSQ reduced the cellular migration, pleural exudate accumulation, and myeloperoxidase activity induced by carrageenan exposure. 4‐PSQ protected against the increase in reactive species levels and reduction of nonprotein thiol levels induced by carrageenan. Data presented here showed that the modulation of serotonergic, nitrergic, and glutamatergic systems contributed to the antinociceptive effect of 4‐PSQ and it reinforced the therapeutic potential of this quinolinic compound for acute inflammation.     

运动训练对小鼠脑局灶缺血后大脑皮质一氧化氮合酶的影响

目的：研究运动训练对小鼠大脑中动脉闭塞（MCAO）后大脑皮质一氧化氮合酶（NOS）的影响。方法：30只雄性C57 BL/6J鼠用Bederson的方法，建立MCAO模型。将MCAO后小鼠随机分为运动组和对照组，每组均15只鼠。运动组：跑笼训练共90d；对照组：跑笼固定不转。分别在MCAO后15d、45d、90d，观察两组小鼠大脑皮质NOS数的改变。结果：MCAO后15d，两组皮质缺血侧、正常侧NOS阳性细胞数差异无显著性意义（t=2．1，0．2，P〉0．05）。45d，运动组比对照组在皮质正常侧NOS阳性细胞数显著增高（t=3．55，P〈0．05），缺血侧差异无显著性意义（t=0．26，P〉0．05）。90d，运动组与对照组比较，NOS阳性细胞计数在正常侧皮质均差异有显著性意义（P〈0．01），而缺血侧各组之间差异无显著性意义（P〉0．05）。结论：运动训练可增加小鼠MCAO后大脑正常侧皮层NOS阳性细胞的数量，对脑的可塑性有一定促讲作用.     

NOS及NO在介导Aβ神经毒性和阿尔茨海默病发病机制中的作用

目的观察诱导型一氧化氮合酶(iNOS)抑制剂胍氨酸(AG)及神经元型一氧化氮合酶(nNOS)抑制剂7-硝基吲哚(7-NI)对β淀粉样蛋白1-40(Aβ1-40)在体神经毒性的干预,进一步探讨一氧化氮合酶(NOS)及一氧化氮(NO)在Aβ神经毒性和Alzheimer病(AD)发病机制中的介导作用。方法雄性SD大鼠35只,随机分为正常对照,生理盐水注射,Aβ1-40注射,AG+Aβ1-40,7-NI+Aβ1-40,花生油(Peanutoil,PO)+Aβ1-40、生理盐水+Aβ1-40共7组,每组5只。观察各组大鼠的Y迷宫学习记忆作业及局部神经元损伤情况。结果Aβ1-40海马组大鼠Y迷宫作业的获得和再现尝试次数均显著增加,分别是(27.8±2.3)和(19.7±4.7)次,与前两组比较有显著性意义(F获得=146.438,P获得=0.000;F再现=113.654,P再现=0.000)。海马齿状回颗粒细胞背侧带受损长度为(1.93±0.26)mm,局部胶质细胞反应明显。AG可逆转Aβ1-40导致的学习记忆和神经元损伤,其获得和再现尝试次数分别为(14.6±4.9)次和(8.5±2.1)次,与Aβ1-40注射组比较明显减少(F获得=146.438,P获得=0.000;F再现=113.654,P再现=0.000)。细胞带受损长度为(0.41±0.21)mm,胶质细胞反应减轻。7-NI则无干预作用。结论iNOS/NO参与了在体条件下对Aβ神经毒性的介导,在AD发病机制中具有重要作用。     

Glutamate and nitric oxide pathway in chronic daily headache: evidence from cerebrospinal fluid

A central sensitization has been advocated to explain chronic daily headache (CDH) due to sustained peripheral sensitization of allogenic structures responsible for sustained trigeminovascular system activation. Several mechanisms have been suggested to underlie central sensitization, but have been poorly investigated in CDH. They involve N-methyl-D-aspartate (NMDA) receptor activation and nitric oxide (NO) production and supersensitivity and increased and maintained production of sensory neuropeptides. The present study supports the above pathogenic mechanisms demonstrating a significant increase in glutamate and nitrite levels in the CSF of CDH patients, without a significant difference between patients without and those with analgesic overuse headache (P < 0.0001 and P < 0.002). The increase in CSF nitrites was accompanied by a significant rise in the CSF values of cyclic guanosine monophosphate (cGMP) in patients in comparison with controls (P < 0.0001). A statistically significant correlation emerged between visual analogic scale (VAS) values and glutamate, nitrites and cGMP. Although substance P (SP) and calcitonin gene-related peptide (CGRP), and to a lesser extent neurokinin A, were significantly increased in CSF compared with control subjects, their values did not correlate with glutamate, nitrites and cGMP levels in CSF in the patient group. The present study confirms the involvement of glutamate-NO-cGMP-mediated events underlying chronic head pain that could be the target of a new therapeutic approach which should be investigated.     

亚低温对急性创伤性脑水肿大鼠一氧化氮及其合成酶变化的影响

目的：探讨亚低温疗法对急性创伤性脑水肿后一氧化氮及其合成酶变化的影响机制。方法：建立大鼠创伤性脑水肿模型,测定伤后不同时间点常温下及亚低温后颈内静脉血一氧化氮、脑组织一氧化氮合成酶和脑含水量。结果：致伤后３０分钟大鼠即出现脑水肿,伤后８小时达高峰（从伤前７７．６３％±０．２１％升至７９．８３％±０．４１％）;一氧化氮具有同步效应〔从伤前（２．４４±０．１２）μｍｏｌ／Ｌ升至（７．８３±０．２７）μｍｏｌ／Ｌ〕;一氧化氮合成酶伤后３０分钟达高峰〔从伤前（３８．８９±４１．３０）μｍｏｌ·ｍｉｎ－１·ｇ－１升至（１０６．５８±５２．４６）μｍｏｌ·ｍｎ－１·ｇ－１〕,以后逐渐下降,伤后８小时〔（５８．２９±１９．４２）μｍｏｌ·ｍｉｎ－１·ｇ－１〕仍高于假手术组。而亚低温（３２～３３℃）能明显减轻脑水肿,减少一氧化氮含量及一氧化氮合成酶的表达〔伤后８小时分别为７９．５６％±０．２７％,（６．８４±０．３７）μｍｏｌ／Ｌ,（５１．０２±２４．５１）μｍｏｌ·ｍｉｎ－１·ｇ－１〕。结论：一氧化氮在创伤性脑水肿发生发展中起作用,而亚低温可能抑制一氧化氮合成酶的表达,减少一氧化氮含量,对创伤性脑水肿有一定保护作用。