D-硝基精氨酸对小鼠肾损伤及氧化应激作用

目的研究D-硝基精氨酸(D-NNA)对小鼠的肾损伤及其氧化应激机制。方法 ICR小鼠ig给予D-NNA150,50和15 mg·kg-1,连续30 d。测定并计算肾系数;血液生化分析仪检测血清中肌酐(Crea)和尿素氮(BUN);分光光度法测定肾组织一氧化氮(NO),硫代巴比妥酸法测丙二醛(MDA)含量,比色法测定谷胱甘肽过氧化酶(GSH-Px)和超氧化物歧化酶(SOD)活性;观察肾病理组织学变化。结果与5%葡萄糖对照组相比,D-NNA 150,50和15 mg·kg-1组血清中BUN分别明显升高了83.6%,36.2%和27.4%(P<0.05),D-NNA150和50 mg·kg-1组血清中Crea分别明显升高了281.6%和10.6%(P<0.05);D-NNA150 mg·kg-1组肾系数和NO水平分别明显降低了5.6%和25.5%(P<0.05);D-NNA150和50 mg·kg-1组肾组织中MDA水平分别明显升高了69.0%和36.9%(P<0.01),SOD活性和GSH-Px活性分别明显下降了17.4%和17.7%,7.3%和13.7%(P<0.05);D-NNA150 mg·kg-1组病理检查可见肾小管损伤,嗜碱性变,萎缩或囊性扩张和间质炎性浸润,D-NNA50和15 mg·kg-1组出现炎症细胞浸润。结论 D-NNA对小鼠肾有一定的损伤作用,其作用机制可能与D-NNA的手性转化产物L-NNA导致NO合成减少,产生ROS有关。     

Role of nitric oxide in the gastric cytoprotection induced by central vagal stimulation

The role of nitric oxide (NO) in the vagal cholinergic-mediated cytoprotective effect of intracisternal (i.c.) injection of the stable thyrotropin-releasing hormone (TRH) analog, RX 77368, was investigated in conscious rats. RX 77368 (1.5 ng i.c.) reduced by 88% gastric hemorrhagic lesions induced by oral administration of ethanol (60%). L-N^G-Nitro-arginine methyl ester (L-NAME, 3 mg/kg i.v.), an inhibitor of NO synthase, abolished the cytoprotection provided by i.c. RX 77368. The effect of L-NAME was reversed by L- but not D-arginine. These results suggest that the L-arginine-nitric oxide pathway is involved in the cytoprotective effect of i.c. TRH analog, probably through the modulation of gastric mucosal blood flow.     

Role of nitric oxide in allergic inflammation and bronchial hyperresponsiveness

The role of nitric oxide (NO) in allergic inflammation and bronchial hyperresponsiveness is unclear. We studied a selective prodrug nitric oxide synthase (NOS)-2 inhibitor, L-N(6)-(1-iminoethyl)lysine 5-tetrazole amide (SC-51). In ovalbumin-sensitized and challenged rats, exhaled NO levels increased by 3 h following challenge (3.73 +/- 0.74 ppb; P < 0.05), peaking at 9 h (11.0 +/- 2.75; P < 0.01) compared to saline controls (1.87 +/- 0.26; P < 0.05 and 2.81 +/- 0.18; P < 0.01). Immunoreactive lung NOS2 expression was increased in ovalbumin-challenged rats compared with ovalbumin-sensitized, saline-challenged rats at 8 h post-challenge. SC-51 (10 mg/kg; p.o.) inhibited allergen-induced increase in exhaled NO levels to 1.3 +/- 0.17 ppb. SC-51 inhibited bronchial hyperresponsiveness in ovalbumin-sensitized and challenged rats (P < 0.05). In sensitized non-exposed rats, SC-51 increased bronchial responsiveness (P < 0.05). SC-51 reduced the allergen-induced increase in bronchoalveolar lavage neutrophils, but caused a nonsignificant reduction in bronchial mucosal eosinophil numbers. NO generated through NOS2 contributes to allergen-induced bronchial hyperresponsiveness but not to bronchial eosinophilia, indicating that these are independently expressed.     

偏头痛患者血浆的一氧化氮含量的研究

目的:为了探讨NO与偏头痛的关系。方法:采用比色法测定62例偏头痛患者血浆NO的含量。结果:偏头痛患者发作期血浆NO含量明显低于正常对照组,间歇期与正常对照组比较无差异。结论:NO可能参与偏头痛发作。     

Balloon angioplasty and induction of non-endothelial nitric oxide synthase in rabbit carotid arteries

The purpose of the study was to evaluate whether balloon angioplasty is associated with changes in nitric oxide synthase (NO synthase) activity. Normal rabbit carotid arteries were examined 10 min or 1, 2, 3 or 10 weeks after angioplasty with 2 or 2.5-mm balloons. Immunohistology was used to evaluate intimal thickening and endothelial cell regeneration. The NO synthase activity was studied functionally using isolated segments in organ chambers. Immunohistochemistry of the endothelial cell markers von Willebrand factor and platelet endothelial cell adhesion molecule-1 indicated that the regeneration of endothelial cells from patchy islands that remained after angioplasty was virtually complete within 2 weeks. However, the endothelium-dependent relaxations elicited by acetylcholine remained impaired up to 10 weeks after dilatation. Contractions elicited by 5-hydroxytryptamine (5-HT) were attenuated, but were significantly augmented by the NO synthase blocker, nitro- -arginine. Furthermore, in contrast to normal arteries, the balloon-treated arteries developed marked contractions in response to nitro- -arginine methyl ester ( -NAME), contractions which could be reversed by -arginine. The latter contractions and relaxations were not influenced by endothelial removal. These results suggest that although the endothelium quickly regenerates after severe balloon injury, the endothelium-dependent release of nitric oxide remains disturbed. However, the functional data also suggest that angioplasty led to a significant induction of NO synthase in ‘non-endothelial’ cells of the artery.     

一氧化氮在顺铂致大鼠肾损害过程中的作用

目的 探讨一氧化氮在顺铂肾毒性氧化应激机制中的作用。方法 采用少量多次给大鼠腹腔注射顺铂（ＣＰ）及经口给予水飞蓟素（ＳＢ）预处理后给予ＣＰ模型,观察血尿素氮（ＢＵＮ）含量、一氧化氮合酶（ＮＯＳ）活性、丙二醛（ＭＤＡ）形成、超氧化物歧化酶（ＳＯＤ）活性等指标的变化。结果 ＣＰ可诱导ＮＯＳ活性增高,使ＮＯ生成量增多;ＢＵＮ含量与ＭＤＡ含量及ＳＯＤ活性的变化并不完全一致,而与ＮＯ含量的时相变化活性增高,     

Endothelium- and nitric oxide-dependent vasorelaxing activities of gamma-butyrobetaine esters: possible link to the antiischemic activities of mildronate

Mildronate [3-(2,2,2-trimethylhydrazine) propionate (THP)] is an antiischemic drug acting mainly via inhibition of fatty acid beta-oxidation. Some effects of the drug cannot be explained by the latter mechanism. We tested the eventual nitric oxide (NO) dependence of the mildronate action. Mildronate, gamma-butyrobetaine (GBB) and GBB methyl ester induced transient increases in nitric oxide (NO) concentrations in rat blood and myocardium. In vitro, these compounds neither modified the activities of purified neuronal and endothelial recombinant nitric oxide synthases (NOSs) nor were able to interact with their active site. GBB induced vasodilatation at high concentrations only (EC50 = 5 x 10(-5) M) while mildronate alone displayed no vasodilating effect although it enhanced the GBB vasodilating activity. GBB methyl and ethyl esters were found more potent vasodilators (EC50 = 2.5 x 10(-6) M). Pretreatment of aortic rings with NOS inhibitor Nomega-nitro-L-arginine methyl ester (L-NAME) abolished vasodilating effects of the compounds. A hypothesis explaining NO and endothelium-dependent effects of mildronate and its analogues is proposed.     

重组人生长激素对败血症大鼠急性肺损伤的治疗及其机制

目的　观察重组人生长激素(rhGH)对败血症大鼠急性肺损伤(ALI)的治疗效果并探讨其作用机制。方法　采用鸵鸟株E .coli复制败血症大鼠ALI模型。观测对照组、ALI组及rhGH治疗组大鼠的肺组织病理评分、支气管肺泡灌洗液(BALF)中NO水平及肺组织诱生型一氧化氮合酶(iNOS)蛋白的表达情况。结果　ALI组大鼠肺组织病理评分、BALF中NO水平及肺组织iNOS蛋白表达水平明显高于对照组,且NO与iNOS蛋白表达水平呈明显正相关。rhGH能明显降低败血症大鼠BALF中NO及肺组织iNOS水平,减轻肺损伤程度。结论　由iNOS诱导产生的过量NO可促进败血症大鼠ALI的发生;rhGH对败血症大鼠ALI具有较理想的治疗效果,其机制可能与rhGH通过影响iNOS表达来降低肺组织NO水平等有关。     

Evidence for muscarinic M4 receptors mediating nonadrenergic noncholinergic relaxations in rabbit anococcygeus muscle

The aim of the present study was to characterize the muscarinic receptor subtype mediating nonadrenergic noncholinergic (NANC) relaxations in the rabbit anococcygeus muscle (RAM) by the use of muscarinic receptor agonists and a battery of key muscarinic antagonists. In addition, experiments were carried out to identify the NANC neurotransmitter(s) involved in the inhibitory NANC neurotransmission. In preparations with histamine-raised tone, the non-selective muscarinic agonists (pD₂ values) (+)-muscarine (5.23), cis-dioxolane (5.16), oxotremorine M (4.95) and carbachol (4.06) produced concentration-dependent relaxations corresponding to 72.6–85.0% of the histamine-induced precontraction. In contrast, the subtype-preferring (M₁/M₄ over M₂ and M₃ receptors) agonists 4-(3-chlorophenylcarbamoyloxy)-2-butynyltrimethylammonium chloride (McN-A-343), (S)-4-(dimethylamino)-1-methyl-2-butynyl-N-(3-chlorophenyl)carbamate methobromide [(S)-BN 228], (R)- and (S)-N-methyl-N-(1-methyl-4-pyrrolidino-2-butynyl)acetamide [(R)- and (S)-BM 5] showed no or rather low [(S)-BN 228] muscarinic activity. The low potencies, together with the ineffectiveness of some agonists, indicated a low effective receptor reserve associated with the relaxant response. No contractile responses to (+)-muscarine were observed neither in unstimulated nor in precontracted preparations suggesting that the existence of an excitatory postjunctional muscarinic receptor may be excluded. The nicotinic antagonist hexamethonium had no influence on relaxant responses to (+)-muscarine, but abolished relaxations elicited by (–)-nicotine. This demonstrates that the RAM contains also nicotinic acetylcholine receptors (AchRs) mediating inhibitory NANC responses. Relaxations induced by the stimulation of muscarinic and nicotinic AchRs as well as by electrical field stimulation (EFS) were completely abolished by tetrodotoxin and were also sensitive to the nitric oxide (NO) synthase inhibitor N^G-nitro-L-arginine (L-NOARG), indicating that NO plays an important role as an inhibitory NANC transmitter in RAM. All muscarinic antagonists investigated did not influence the histamine-induced precontraction, but shifted the concentration-response curve of (+)-muscarine to the right in a parallel fashion. Schild analysis yielded regression lines of unit slope, indicating competitive antagonism. The following rank order of antagonist potencies (pA₂ values) was found: 11-({4-[4-(diethylamino)-bu-tyl]-1-piperidinyl}-acetyl-5,11-dihydro-6H-pyrido (2,3-b) (1,4)-benzodiazepine-6-one hydrochloride (AQ-RA 741; 8.08) = himbacine (8.03) ≥ tripitramine (7.69) ≥ p-fluoro-hexahydro-sila-difenidol (p-F-HHSiD; 7.48) ≥ methoctramine (7.30) ≥ pirenzepine (7.18) ≥ guanylpirenzepine (6.24). A comparison of the pA₂ values determined in the RAM with published data from binding studies at muscarinic M₁–M₄ and m5 receptors suggests that the functional muscarinic receptor mediating NANC relaxation in the RAM is of the M₄ subtype. Taken together, the results obtained in the present study provide convincing evidence that relaxant responses elicited by muscarinic stimuli in RAM are nitrergic in nature and mediated by muscarinic M₄ receptors located somadendritically on NANC neurons. Thus, the isolated RAM may serve as a functional muscarinic M₄ receptor model. Received: 4 March 1997 / Accepted: 24 June 1997     

Roles of brain prostaglandin E2 and thromboxane A2 in the activation of the central sympatho-adrenomedullary outflow in rats

This study addressed the question whether proximal and distal guinea pig tracheal segments respond differently to contractile agents. Using a perfused trachea set-up, histamine, KCl or the cyclo-oxygenase inhibitor, indomethacin, could be administered selectively to the mucosa (at the inside) or the serosa (at the outside) of the tracheal segments. Proximal parts contracted significantly more (40-60%) than distal parts when 1 mM histamine was administered to the mucosal or serosal side or when KCl (50 mM) was added to the serosal side. When histamine was administered to the mucosal side of epithelium-denuded segments, the contractions were twice as high in proximal than in distal parts (3057 vs. 1526 mg). Inhibition of tracheal cyclo-oxygenase with indomethacin at the mucosal side increased proximal and distal reactivity to mucosally administered histamine to the same extent. Serosal administration of indomethacin, however, increased histamine reactivity only in proximal segments (from 2690 to 5180 mg). In the latter segments, subsequent administration of histamine to the serosal side further increased the contraction, while serosal histamine in the absence of serosal indomethacin produced a relaxation (net difference of 4672 mg). In conclusion, the higher intrinsic contractility of proximal tracheal segments is counteracted by serosal cyclo-oxygenase products.     

Attenuation of morphine tolerance and dependence by aminoguanidine in mice

The effect of aminoguanidine, an inducible nitric oxide synthase (iNOS) inhibitor, on morphine-induced tolerance and dependence in mice was investigated in this study. Acute administration of aminoguanidine (20 mg/kg, p.o.) did not affect the antinociceptive effect of morphine (10 mg/kg, s.c.) as measured by the hot plate test. Repeated administration of aminoguanidine along with morphine attenuated the development of tolerance to the antinociceptive effect of morphine. Also, the development of morphine dependence as assessed by naloxone-precipitated withdrawal manifestations was reduced by co-administration of aminoguanidine. The effect of aminoguanidine on naloxone-precipitated withdrawal was enhanced by concurrent administration of the non-competitive N-methyl-d-aspartate (NMDA) receptor antagonist, dizocilpine (0.25 mg/kg, i.p.) or the non-specific nitric oxide synthase (NOS) inhibitor, l-N(G)-nitroarginine methyl ester (l-NAME; 5 mg/kg, i.p.) and antagonized by concurrent administration of the nitric oxide (NO) precursor, l-arginine (50 mg/kg, p.o.). Concomitantly, the progressive increase in NO production, but not in brain glutamate level, induced by morphine was inhibited by repeated administration of aminoguanidine along with morphine. Similarly, co-administration of aminoguanidine inhibited naloxone-induced NO overproduction, but it did not inhibit naloxone-induced elevation of brain glutamate level in morphine-dependent mice. The effect of aminoguanidine on naloxone-induced NO overproduction was potentiated by concurrent administration of dizocilpine or l-NAME and antagonized by concurrent administration of l-arginine. These results provide evidence that blockade of NO overproduction, the consequence of NMDA receptor activation, by aminoguanidine, via inhibition of iNOS, can attenuate the development of morphine tolerance and dependence.     

Induction of vasorelaxation through activation of nitric oxide synthase in endothelial cells by brazilin

The vasorelaxant activity of Caesalpinia sappan L., a traditional Chinese medicine, and its major component brazilin were investigated in isolated rat aorta and human umbilical vein endothelial cells. In isolated rat aorta, C. sappan L. extract and brazilin relaxed phenylephrine-induced vasocontraction and increased cyclic guanosine 3',5'-monophosphate (cGMP) content. Induction of vasorelaxation of brazilin was endothelium-dependent and could be markedly blocked by pretreatment with nitric oxide synthase (NOS) inhibitor, N(G)-nitro-L-arginine methyl ester (L-NAME); N(G)-monomethyl-L-arginine acetate (L-NMMA) and guanylyl cyclase inhibitor, methylene blue; 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) and nitric oxide (NO) scavenger, hemoglobin. The increasing cGMP content induced by brazilin was also blocked by pretreatment with L-NAME, methylene blue, and the removal of extracellular Ca(2+). In human umbilical vein endothelial cells, brazilin dose-dependently induced an increase in NO formation and NOS activity, which were greatly attenuated by either the removal of extracellular Ca(2+) or the chelating of intracellular Ca(2+) chelator, 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA-AM). Moreover, brazilin dose-dependently induced the influx of extracellular Ca(2+) in human umbilical vein endothelial cells. Collectively, these results suggest that brazilin induces vasorelaxation by the increasing intracellular Ca(2+) concentration in endothelial cells of blood vessels and hence activating Ca(2+)/calmodulin-dependent NO synthesis. The NO is released and then transferred into smooth muscle cells to activate guanylyl cyclase and increase cGMP content, resulting in vasorelaxation.     

Naltrexone attenuates plasma nitric oxide release following acute heat stress

Previous studies have shown that naltrexone attenuates morbidity and mortality in heat stress by inhibiting endogenous opioids. In this study, we hypothesized that naltrexone can decrease heat stress by attenuating nitric oxide release. Male Sprague-Dawley rats were pretreated with naltrexone or normal saline, and exposed to 45 degrees C for 25 min; controls were exposed to 25 degrees C. Colonic temperatures were recorded and plasma samples from an in-dwelling i.v. cannula were analyzed for nitrate/nitrite levels. Following heat stress, peak colonic temperature was significantly diminished (P < 0.05) in naltrexone-treated rats compared to saline-treated rats. Plasma nitrate/nitrite levels were significantly lower (P < 0.05) in naltrexone-treated rats compared to saline-treated rats. These findings suggest that naltrexone is able to attenuate the rise in plasma nitric oxide levels commonly observed after heat stress.     

Role of capsaicin-sensitive afferent neurons in receptive relaxation induced by gastric distension in rats

We investigated the role of capsaicin-sensitive afferent neurons in receptive relaxation of the rat stomach in response to distension. Under urethane anesthesia, a balloon with barostat was inserted through the pylorus and placed in the forestomach. Isobaric distension was performed in a stepwise increment of 2 mmHg, each lasting for 2 min, while the corresponding intragastric volume was recorded. Gastric distension produced the intraballoon volume in a progressive manner with saturation, suggesting the occurrence of receptive relaxation of the stomach during distension. Intragastric application of capsaicin significantly enhanced the degree of receptive relaxation. The capsaicin-induced enhancement of receptive relaxation was totally abolished by bilateral vagotomy as well as chemical ablation of capsaicin-sensitive afferent neurons. Likewise, the enhanced receptive relaxation in response to stomach distension was also significantly attenuated by pretreatment of the animals with N^G-nitro-L-arginine methyl ester (L-NAME, an inhibitor of nitric oxide (NO) synthase), calcitonin gene related peptide (CGRP)_8-37 (CGRP antagonist), indomethacin and ONO-8711 (EP1 receptor antagonist). These results suggest that capsaicin significantly enhanced the receptive relaxation induced by gastric distention through both vagal nerves and capsaicin-sensitive afferent neurons. This process is intervened by endogenous NO and CGRP in addition to prostaglandins (PGs), and the effect of PGs may be mediated by EP1 receptors. Received 9 October 2006; accepted 10 November 2006     

Helicobacter pylori lipopolysaccharide-provoked injury to rat gastroduodenal microvasculature involves inducible nitric oxide synthase

The actions of a purified Helicobacter pylori lipopolysaccharide (3 mg kg⁻¹, i.v.) on rat gastric antral and duodenal microvascular integrity (determined as radiolabelled albumin leakage) and the expression of the inducible nitric oxide (NO) synthase (iNOS; assessed by the citrulline assay) were investigated 4 h after challenge. Significant increases of albumin leakage and expression of iNOS in both antral and duodenal tissues were observed following challenge. Concurrent administration of the selective iNOS inhibitor, 1400W (N-(8-(aminomethyl)benzyl)-acetamidine; 0.2–1 mg kg⁻¹, s.c.), with lipopolysaccharide, caused a dose-dependent attenuation of the gastric and duodenal albumin leakage. Thus, H. pylori lipopolysaccharide can initiate the expression of iNOS in the stomach and duodenum following systemic challenge, which can provoke gastroduodenal microvascular dysfunction.     

Brain inducible nitric oxide synthase is involved in interleukin-1beta-induced activation of the central sympathetic outflow in rats

Nitric oxide (NO) has been recognized as a neurotransmitter or a neuromodulator in the central nervous system. Brain NO is mainly generated either by neuronal NO synthase (NOS) or by inducible NOS. Previously we reported that central NO is involved in the elevation of plasma noradrenaline levels induced by intracerebroventricularly (i.c.v.) administered interleukin-1beta in rats [Eur. J. Phamacol. 317 (1996) 61]. In the present study, therefore, we tried to characterize which type of NOS isoforms is involved in the cytokine-induced responses using selective inhibitors of each NOS isoform in urethane-anesthetized rats. I.c.v. administered interleukin-1beta (100 ng/animal) elevated plasma levels of noradrenaline but not adrenaline. The cytokine-induced elevation of plasma noradrenaline levels was attenuated by cycloheximide, an inhibitor of protein synthesis, in a dose-dependent manner (10 and 20 microg/animal, i.c.v.). S-ethylisothiourea (0.1 and 0.5 microg/animal, i.c.v.), an inhibitor of inducible NOS, dose-dependently reduced the cytokine-induced elevation of plasma noradrenaline levels, while 7-nitroindazole (5 and 10 microg/animal, i.c.v.), an inhibitor of neuronal NOS, had no effect. These results suggest the involvement of brain inducible NOS in the interleukin-1beta-induced activation of the central sympathetic outflow in rats.     

Cyclic GMP stimulation by vasopressin in LLC-PK1 kidney epithelial cells is l-arginine-dependent

Summary The l-arginine antagonist N^G-monomethyl-l-arginine has been shown to inhibit nitric oxide formation from l-arginine in endothelial cells. In the present study N^G-monomethyl-l-arginine was used to assess the role of l-arginine for cyclic GMP stimulation by vasopressin in a kidney epithelial cell line (LLC-PK₁). Preincubation of cells with 1 mol/l, 10 mol/l and 100 mol/l N^G-monomethyl-l-arginine decreased cyclic GMP stimulation at 1 mol/l vasopressin by 25%, 71% and 90%, respectively. This inhibition by N^G-monomethyl-l-arginine was markedly reduced by l-arginine (2 mmol/1) but not d-arginine (2 mmol/1). Cyclic GMP stimulation by the calcium ionophore A23187 was also inhibited by N^G-monomethyl-l-arginine and enantioselectively restored by l-arginine. However, N^G-monomethyl-l-arginine did not affect cyclic GMP stimulation by sodium nitroprusside that spontaneously releases nitric oxide. These results suggest that, in kidney epithelial cells, vasopressin induces nitric oxide formation from l-arginine leading to activation of soluble guanylate cyclase. It is concluded that nitric oxide formation from l-arginine is not only responsible for endothelium-dependent relaxation but may be a more general pathway with regulatory function for intracellular guanylate cyclase activity.Send offprint requests to K. Schror at the above address     

冠心病患者血一氧化氮/一氧化氮酶和内皮素检测的临床意义

目的　探讨了 NO/ NOS和 ET在冠心病患者中的变化。方法　分别应用生化法和放免法检测了3 9例冠心病患者血 NO/ NOS和 ET含量 ,并与 3 5名正常健康人作对照。结果　冠心病患者血 NO水平低于正常人 ( P<0 .0 5 ) ,NOS和 ET水平高于正常人 ( P<0 .0 1)。结论　 NO/ NOS和 ET水平的变化与冠心病的发生与发展密切相关     

银杏黄酮苷对氧化损伤内皮细胞产生NO、eNOS和ICAM-1的影响

目的观察银杏黄酮苷对氧化损伤的人脐静脉内皮细胞（HUVEC）产生NO、内皮型一氧化氮合酶（eNOS）和人可溶性细胞间黏附分子（ICAM-1）的影响。方法体外培养HUVEC,传至3代后,以不同浓度的银杏黄酮苷分别作用于HUVEC,然后进行氧化损伤处理。以硝酸还原酶法测定培养液上清中的NO水平,免疫细胞化学法检测内皮细胞eNOS的表达,ELISA法测定细胞培养液中ICAM-1的含量。结果HUVEC在氧化损伤（H2O2100μmol/L,2h）后产生NO的量显著减少（P〈0.01）,eNOS表达下调,ICAM-1表达上调;银杏黄酮苷可以剂量依赖性的增加内皮细胞NO生成量,上调eNOS的表达,下调ICAM-1表达。结论银杏黄酮苷可能通过增加HUVEC eNOS的表达增加N0的释放、抑制ICAM-1的表达等机制对内皮细胞起保护作用。