卡托普利对尼古丁所致大鼠血管内皮功能损伤的保护作用

目的:探讨卡托普利对尼古丁损伤大鼠肠系膜动脉内皮依赖性舒张功能的保护作用及其机制。方法:将30只大鼠分为3组,即正常对照组、尼古丁损伤组(2mg·kg-1)、卡托普利组(尼古丁2mg·kg-1+卡托普利3mg·kg-1),4周后检测各组肠系膜动脉环血管舒张率及血清一氧化氮(NO)含量,一氧化氮合成酶(NOS)、超氧化物歧化酶(SOD)活性。结果:尼古丁使肠系膜动脉环血管舒张率明显降低,并伴随血清NO含量及NOS、SOD活性的明显下降(P<0.01或P<0.05);而卡托普利可升高血管舒张率,并且抑制了尼古丁诱导的NO含量及NOS、SOD活性的下降(P<0.01)。结论:卡托普利对尼古丁所致的血管内皮功能损伤具有明显保护作用,该作用可能与其抗氧化、促进内皮细胞合成、释放NO有关。     

洛伐他汀对低密度脂蛋白损伤血管内皮的保护作用

目的：探讨洛伐他汀对低密度脂蛋白所致血管内皮功能损伤的保护作用及可能的机制．方法：一次性从大鼠舌下静脉注射天然低密度脂蛋白(n-LDL 4mg／kg),在舌下静脉注射n-LDL之前大鼠腹腔注射洛伐他汀(2或4mg／kg),每天一次,连续五天．注射n-LDL后48小时检测乙酰胆碱诱导的血管内皮依赖性舒张(EDR)及血清一氧化氮(N0)、丙二醛(MDA)的含量和超氧化物歧化酶(SOD)的活性．结果：一次注射n-LDL导致了EDR、血清NO水平及SOD活性明显降低,MDA的浓度明显增高。预先给予洛伐他汀能明显减轻LDL引起的EDR的抑制和血清NO水平及SOD活性的降低,减少MDA的生成,左旋硝基精氨酸(L-NNA)减弱洛伐他汀对血管内皮的保护作用．结论：洛伐他汀对LDL损伤的血管内皮具有保护作用,可能与保护内皮依赖性松弛因子和抗氧化作用有关。     

胰岛素抵抗状态下血红素氧合酶-1/一氧化碳与一氧化氮合酶/一氧化氮相互调节的研究

目的探讨胰岛素抵抗状态下血红素氧合酶-1（HO-1）／一氧化碳（CO）与一氧化氮合酶（NOS）／一氧化氮（NO）的相互调节关系。方法通过6周高脂饮食成功复制胰岛素抵抗SD大鼠模型44只，分为胰岛素抵抗组26只，正铁血红素组10只，锌原卟啉组8只；分别腹腔注射生理盐水、正铁血红素、锌原卟啉。12只经6周普通饲料喂养的SD大鼠为对照组，给予腹腔注射生理盐水。检测血CO含量以及胸主动脉组织的NO、诱导型NOS（iNOS）、内皮型NOS（eNOS）的水平，RT-PCR检测主动脉iNOS、eNOS mRNA的表达。结果正铁血红素提高胰岛素抵抗大鼠主动脉组织eNOS活性及其mRNA表达，降低iNOS活性及其mRNA表达。降低血清及动脉组织的NO水平。增加动脉血CO水平。结论HO-1通过对NOS／NO信息通道的调节。抑制iNOS的活性，从而使应激状态下NO水平下降。发挥HO-1的血管保护作用。     

卡托普利对蛋氨酸所致血管内皮功能损伤的保护作用与对氧磷酶1的关系

目的探讨卡托普利对高蛋氨酸饮食所致大鼠血管内皮功能损伤的保护作用及其机制。方法将蛋氨酸通过灌胃的方法,1次.d-1,连续4周,诱导大鼠血管功能损伤,治疗组同时给予卡托普利、依那普利、N-乙酰半胱氨酸灌胃。4周后处死动物,检测血清一氧化氮(nitric oxide,NO)、丙二醛(malondialdehyde,MDA)含量、对氧磷酶(paraoxonase 1,PON1)、超氧化物歧化酶(superoxide dismutase enzyme,SOD)、血管紧张素转换酶(an-giotensin-converting enzyme,ACE)活性。取胸主动脉检测由乙酰胆碱(acetylcysteine,Ach)诱导的血管内皮依赖性舒张反应。结果高蛋氨酸损伤组大鼠血管内皮依赖性舒张反应显著减弱,血清中MDA浓度升高,PON1活性、血浆NO浓度与SOD活性降低;卡托普利、N-乙酰半胱氨酸和依那普利能显著改善血管内皮依赖性舒张反应、降低MDA浓度、提高血清中的PON1活性、SOD活性和NO浓度。结论卡托普利能够改善高蛋氨酸引起的血管内皮功能的损伤,该作用可能与保护PON1活性及其抗氧化作用、促进内皮细胞释放NO有关。     

活血逐瘀方浸膏的舒张血管作用及其作用机制

目的观察活血逐瘀方浸膏的舒张血管作用，并探讨其作用机制。方法采用豚鼠肠系膜微血管和大鼠体外主动脉环研究活血逐瘀方浸膏舒张血管作用;硝酸还原酶法测定血浆一氧化氮(NO)和血管NO、一氧化氮合酶(NOS)、原生型一氧化氮合酶（cNOS）及诱生型一氧化氮合酶（iNOS）的活性。结果活血逐瘀方浸膏有抗去甲肾上腺素致豚鼠肠系膜微血管收缩的作用;松弛苯肾上腺素引起体外大鼠胸主动脉环收缩的作用，预加格列本脲或普萘洛尔后仍然有松弛作用，而去内皮后引起收缩作用;高剂量的活血逐瘀方浸膏非常显著性地升高血浆NO及主动脉NO含量、提高NOS和cNOS的活性;低剂量活血逐瘀方浸膏显著性提高血管cNOS的活性。结论活血逐瘀方浸膏有舒张血管的作用，其作用机制可能与其激活血管NOS、cNOS活性和促进血管内皮NO释放有关。     

洛伐他汀对溶血性磷脂酰胆碱引起的离体血管内皮损伤的保护作用

目的探讨洛伐他汀（Lov）对溶血性磷脂酰胆碱（LPC）所致血管内皮损伤的保护作用及机制。方法利用家兔离体胸主动脉环和培养的人内皮细胞模型,分别观察洛伐他汀对LPC致离体血管环内皮依赖性舒张反应的损伤及对内皮细胞合成NO的损伤的保护作用。血管环分别与LPC（4 mg.L-1）和洛伐他汀（0.025、0.05、0.1μmol.L-1）单独孵育和共孵各15 min,分别检测乙酰胆碱（ACh）诱导的内皮依赖性舒张（EDR）反应及硝普钠诱导的非内皮依赖性舒张（EDR）反应及血管组织中的脂质过氧化物产物丙二醛（MDA）的含量。在培养的人内皮细胞和培养基中分别加入LPC和洛伐他汀,分别检测LPC和洛伐他汀对内皮细胞中一氧化氮（NO）含量和一氧化氮合酶（eNOS）的影响。结果LPC（4 mg.L-1）与血管环孵育15 min,引起了血管EDR的显著降低,最大舒张比值较对照组明显减小（P〈0.01）,洛伐他汀剂量依赖性地减轻了LPC对血管EDR的损伤作用,其最大舒张比值较LPC损伤组明显增加,（P〈0.01）。LPC和洛伐他汀对硝普钠诱导的非内皮依赖性舒张反应无明显影响。LPC引起了血管组织中MDA浓度明显升高,与对照组相比有显著性差异（P〈0.01） 不同浓度的洛伐他汀与血管环预孵后再与LPC孵育,剂量依赖性地减少了LPC所增加的MDA浓度,与LPC损伤组比较有显著差异（P〈0.01）。LPC与培养的内皮细胞孵育,导致了内皮细胞NO含量和eNOS活性的降低,不同浓度的洛伐他汀与内皮细胞预孵后再与LPC孵育,剂量依赖性地提高eNOS活性和NO的含量。结论LPC能直接抑制血管的EDR反应,洛伐他汀能剂量依赖性地拮抗LPC对EDR反应的抑制作用。其机制可能与LPC触发脂质过氧化反应,从而抑制血管内皮细胞NO的合成和增加NO的消耗有关,洛伐他汀通过抗氧化而保护血管内皮细胞的功能。     

MC-002对脑缺血再灌注损伤大鼠脑组织及血清中NO及NOS的影响

目的 研究MC-002对脑缺血再灌注损伤大鼠脑组织及血清中一氧化氮（NO）、一氧化氮合酶（NOS）含量的影响,探讨其对脑缺血再灌注损伤保护作用的机制.方法 采用改良线栓法,建立大鼠大脑中动脉栓塞（MCAO）脑缺血再灌注模型.将雄性SD大鼠随机分为假手术组、模型组、奥扎格雷钠组（18mg/kg）和MC-002高、中、低剂量组（30、18、10.8mg/kg）.缺血再灌注24h后检测脑组织及血清中NO含量、NOS活性.结果 与假手术组相比,模型组脑组织和血清中NO含量和NOS活性明显升高;与模型组相比,MC-002高、中、低剂量组脑组织和血清中NO含量和NOS活性均明显降低（P＜0.01、0.05）.结论 MC-002对大鼠脑缺血再灌注损伤具有明显的保护作用,其机制可能与降低NOS活性,减少NO含量有关.     

雄激素对大鼠主动脉一氧化氮合酶/一氧化氮体系的调节

目的：研究雄激素对大鼠主动脉一氧化氮合酶／一氧化氮(NOS／NO)体系的影响，以探讨雄激素对心血管系统的作用。方法：将30只雄性大鼠随机分为三个组，每组10只，去卵巢组(A组)、去卵巢 雄激素组(B组)、假手术组(C组)。正常饮食2个月后处死大鼠，测血清雄激素、主动脉匀浆一氧化氮合酶活性及一氧化氮含量。结果：同假手术组相比。去势大鼠主动脉匀浆NOS活性及NO含量显著降低，在补充适量的雄激素后．主动脉匀浆NOS活性及NO含量显著上升。结论：雄激素可以调节大鼠动脉内一氧化氮合酶／一氧化氮体系，可能是其调节血管张力的作用机制。     

复方丹参滴丸对心肌保护作用的实验研究

为探讨复方丹参滴丸（DSP）对心肌损伤的保护作用机制，将120只大鼠随机分为4组：异丙肾上腺素（ISO）损伤组、DSP保护组、DSP＋ISO组及正常对照组。应用ISO腹腔内注射造成心肌缺血损伤，测定大鼠血清及心肌组织中脂质过氧化物丙二醛（MDA）含量、超氧化物歧化酶（SOD）活性及血浆中内皮素（ET）和血清中一氧化氮（NO）含量的变化。结果表明，DSP保护组血浆中NO含量升高，与正常对照组差异有显性；DSP保护组注射ISO后MDA、SOD、ET及NO变化程度明显小于单纯ISO组，差异有显性。结论：复方丹参滴丸具有良好的抗急性心肌缺血损伤作用，其作用机制与抗自由基及血管内皮保护效应密切相关。     

原花青素对D-半乳糖复合三氯化铝诱导大鼠主动脉损伤的保护作用及机制

目的：探讨原花青素对D-半乳糖复合三氯化铝诱导大鼠主动脉损伤的保护作用及可能机制。方法： 采用D-半乳糖（D-gal）腹腔注射（ip）180mg/kg/d 联合三氯化铝（AlCl3）灌胃（ig）15mg/kg/d建立主动脉损伤大鼠模型,12周后将40只大鼠随机分为空白对照组（NS ip,NS ig）,主动脉损伤组（D-gal ip ＋ AlCl3 ig）,原花青素低、高剂量组（PC 20、40 mg/kg; D-gal ip＋AlCl3 ig）,维生素E组（VitE 10 mg/kg;D-gal ip ＋ AlCl3 ig）,每组8只。每日灌胃给药一次,连续8周。于末次给药后,尾袖法测量大鼠尾动脉血压;离体灌流法观察主动脉环对乙酰胆碱的舒张反应;HE染色观察主动脉病理变化;化学比色法测定血清总抗氧化能力、过氧化氢以及一氧化氮含量;免疫组化法观察主动脉内皮型一氧化氮合酶（eNOS）表达。结果：与模型组相比,随着原花青素剂量的增加,大鼠血压逐渐降低,主动脉内皮依赖性舒张功能逐渐增强,主动脉病理损伤得到不同程度的改善;血清中T-AOC 和NO含量逐渐增高,H2O2含量逐渐降低;主动脉eNOS蛋白表达逐渐增加。结论：原花青素可明显降低主动脉血压,增强主动脉环内皮依赖性舒张反应,减轻主动脉病理损伤,增高血清NO水平,上调主动脉eNOS蛋白的表达,对D-半乳糖复合三氯化铝诱导的大鼠主动脉损伤有一定保护作用。     

The protective effect of captopril on nicotine-induced endothelial dysfunction in rat

This study was designed to examine the in vivo and in vitro effects of captopril, an angiotensin-converting enzyme inhibitor, on nicotine-induced endothelial dysfunction in rats. Endothelial dysfunction was induced by exposing isolated rat mesenteric arteries to nicotine (0.01, 0.1, or 1 mM) for 24 hr using an organ culture system, or by treating rats with nicotine (2 mg/kg/day, intraperitoneally) for 4 weeks. The protective effects of captopril were tested by exposing isolated mesenteric arteries to captopril (0.01, 0.03, or 0.1 mM) + nicotine (0.1 mM) for 24 hr, or by treating rats with captopril (3 mg/kg/day, intravenously) + nicotine (2 mg/kg/day, intraperitoneally) for 4 weeks. Exposure of the isolated mesenteric arteries to nicotine induced a significant concentration -dependent inhibition of endothelium-dependent relaxation. Co-culture of segments of mesenteric artery with captopril (0.03 or 0.1 mM) attenuated the nicotine-induced impairment of vasorelaxation in a dose-dependent manner. Administration of nicotine to rats for 4 weeks significantly impaired endothelium-dependent relaxation compared with control rats. This impairment was accompanied by a reduction in nitrite/nitrate, nitric oxide (NO) synthase (NOS), and superoxide dismutase (SOD) activities in the serum and aorta. Chronic captopril treatment not only improved the impairment of endothelium-dependent relaxation, but also prevented the reduction of nitrite/nitrate contents and of NOS and SOD activities in the serum and aorta. However, there were no significant differences in serum angiotensin-converting enzyme activity among the three groups. These results indicate that captopril can be used to attenuate nicotine-induced endothelial dysfunction, an effect that may be related not only to antioxidation, but also to enhancing NO production by preventing the decrease in NOS.     

Protective effects of ACE inhibitors on vascular endothelial dysfunction induced by exogenous advanced oxidation protein products in rats

To explore detrimental effects of advanced oxidation protein products-bovine serum albumin (BSA) on endothelial function and compare the favorable effects of angiotensin-converting enzyme (ACE) inhibitors: captopril and enalapril. Male Sprague-Dawley rats were randomly divided into groups: control, advanced oxidation protein products-BSA, captopril (10, 20 mg/kg/day), enalapril (15 mg/kg/day), and N(G)-nitro-l-arginine methyl ester (l-NAME, 300 mg/kg/day) plus captopril (20 mg/kg/day) groups. All animals were given advanced oxidation protein products-BSA (100 mg/kg/day, i.v.) except for control group (iv. equal volume of PBS). Rats in other groups were received different drugs intragastrically after advanced oxidation protein products-BSA administration. Endothelium-dependent relaxation of thoracic aorta was assayed. Content of nitrite/nitrate (NO), malondialdehyde (MDA), activities of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and of ACE in Sera, as well as renal function index including blood urea nitrogen and creatinine were measured. After 30 days, the endothelium-dependent relaxation of blood vessels in received advanced oxidation protein products-BSA rats was significantly impaired compared with control rats. The impairment was accompanied by decreases of serum NO, activity of GSH-Px and SOD. Administration of captopril and enalapril not only decreased damage of endothelium-dependent relaxation, but also reverse the changes of MDA levels, NO content and activity of SOD. The protective effect of captopril was abolished by L-NAME. Blood urea nitrogen and creatinine had no significant differences between various groups. ACE activities were decreased in high captopril and enalapril groups, but did not significantly change in other groups. The results suggested that captopril and enalapril have similar effects on endothelial dysfunction induced by advanced oxidation protein products-BSA, which indicated that protective effects of captopril are not related to sulfhydryl group.     

A reduction of endogenous asymmetric dimethylarginine contributes to the effect of captopril on endothelial dysfunction induced by homocysteine in rats

We examined whether captopril exerts beneficial effect on homocysteine-induced endothelial dysfunction in vivo and whether this effect of captopril is associated with a reduction of endogenous inhibitor of nitric oxide synthase (NOS) asymmetric dimethylarginine (ADMA) in rats. Male Sprague-Dawley rats were given intravenous injections of homocysteine (10 mg/kg/day) to induce endothelial dysfunction. Captopril treatment (3 mg/kg/day, i.v.) was taken in some rats after homocysteine administration. Endothelium-dependent relaxation was tested in aortic rings. Serum levels of ADMA, nitrite/nitrate, malondialdehyde (MDA), and creatinine were measured. Furthermore, superoxide dismutase activity in liver and angiotensin converting enzyme activity in serum were also assayed. Administration of homocysteine to rats for 4 weeks significantly impaired endothelium-dependent relaxation compared with control rats. This impairment of endothelium-dependent relaxation was accompanied by elevated serum concentration of ADMA and decreased serum content of nitrite/nitrate. Moreover, serum concentration of MDA was remarkably increased, whereas liver superoxide dismutase activity was decreased in homocysteine-treated group compared with control. Chronic captopril treatment not only improved the impaired endothelium-dependent relaxation, but also prevented the elevation of serum ADMA and MDA levels, as well as reduction of serum nitrite/nitrate contents and liver superoxide dismutase activity. Serum angiotensin converting enzyme activity and creatinine had no significant difference between the three groups. These results suggest that chronic captopril treatment reduces endogenous inhibitor of NOS in rats with homocysteine injection, which may contribute to the beneficial effect of captopril on homocysteine-induced endothelial dysfunction in vivo, and may be secondary to the antioxidative action of captopril.     

Protective mechanism of adenosine to the rat arterial endothelial dysfunction induced by hydrogen peroxide

This study was designed to examine the in vitro effects of adenosine (Ado) on hydrogen peroxide-induced endothelial dysfunction in rats. Endothelial dysfunction was induced by exposing isolated rat mesenteric arteries to hydrogen peroxide (0.5 mM) for 12 h using an organ culture system. The protective effects of adenosine were tested by exposing isolated mesenteric arteries to adenosine (3 x 10(-7) mol/l, 10(-6) mol/l, 3 x 10(-6) mol/l)+hydrogen peroxide (0.5 mM) for 12 h. This exposure to hydrogen peroxide induced a significant concentration-dependent inhibition of endothelium-dependent relaxation (EDR). Coculture of segments of mesenteric artery with adenosine (3 x 10(-7), 10(-6), and 3 x 10(-6) mol/l) attenuated the hydrogen peroxide-induced impairment of vasorelaxation. This impairment was accompanied by a reduction in nitrite/nitrate, nitric oxide (NO) synthase (NOS), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities and an increasing in malondislehyde (MDA) and lactate dehydrogenase (LDH) activities in the aorta. These results indicate that adenosine can be used to attenuate hydrogen peroxide-induced endothelial dysfunction, an effect that may be related to antioxidation, thus enhancing NO production by preventing the decrease in NOS.     

Interleukin-2 protects against endothelial dysfunction induced by high glucose levels in rats

AIMS: Interleukin-2 (IL-2) can modulate cardiovascular functions, but the effect of IL-2 on vascular endothelial function in diabetes is not known. We hypothesized that IL-2 may attenuate endothelial dysfunction induced by high glucose or diabetes. So the aim of this study was to investigate the effect of IL-2 on endothelium-response of aortas incubated with high glucose or from diabetic rats and its underlying mechanism. METHODS: Acetylcholine (ACh)-induced endothelium-dependent relaxation (EDR), sodium nitroprusside (SNP)-induced endothelium-independent relaxation (EIR), superoxide dismutase (SOD) and nitric oxide synthase (NOS) were measured in aortas isolated from non-diabetic rats and exposed to a high glucose concentration and from streptozotocin-induced diabetic rats. RESULTS: Incubation of aortic rings with high glucose (44 mM) for 4 h resulted in a significant inhibition of EDR, but had no effects on EIR. Co-incubation with IL-2 for 40 min prevented the inhibition of EDR caused by high glucose in a concentration-dependent manner. Similarly, high glucose decreased SOD and NOS activity in aortic tissue. IL-2 (1000 U/ml) significantly attenuated the decrease of SOD and NOS activity caused by high glucose. In addition, EDR declined along with the decrease of serum NO level in aortas from STZ-induced diabetic rats. Injection of IL-2 (5000 and 50,000 U kg(-1) d(-1), s.c.) for 5 weeks prevented the inhibition of EDR and the decrease of serum NO levels caused by diabetes. CONCLUSIONS: IL-2 significantly ameliorated the endothelial dysfunction induced by hyperglycemia, in which the activation of the NO pathway and SOD may be involved.     

Impairment of endothelium-dependent relaxation of rat aortas by homocysteine thiolactone and attenuation by captopril

To explore the effects of angiotensin-converting enzyme (ACE) inhibitors on endothelial dysfunction induced by homocysteine thiolactone (HTL). Both endothelium-dependent relaxation and nondependent relaxation of thoracic aortic rings in rats induced by acetylcholine (Ach) or sodium nitroprusside (SNP) and biochemical parameters including malondialdehyde (MDA) and nitric oxide (NO) were measured in rat isolated aorta. Exposure of aortic rings to HTL (3 to 30 mM) for 90 minutes made a significant inhibition of endothelium-dependent relaxation induced by Ach, decreased contents of NO, and increased MDA concentration in aortic tissue. After incubation of aortic rings with captopril (0.003 to 0.03 mM) attenuated the inhibition of endothelium-dependent relaxation (EDR) and significantly resisted the decrease of NO content and elevation of MDA concentration caused by HTL (30 mmol/L) in aortic tissues, a similarly protective effect was observed when the aortic rings were incubated with both N-acetylcysteine (0.05 mM). Treatment with enalaprilat (0.003 to 0.01 mM) made no significant difference with the HTL (30 mM) group regarding EDR, but enalaprilat (0.03 mM) and losartan (0.03 mM) could partly restore the EDR in response to HTL (30 mM). Captopril was more effective than enalaprilat and losartan in attenuation of the inhibition of on acetylcholine-stimulated aortic relaxation by HTL in the same concentration. Moreover, superoxide dismutase (SOD, 200 U/mL), which is a scavenger of superoxide anions, apocynin (0.03 mM), which is an inhibitor of NADPH oxidase, and l-Arginine (3 mmol/L), a precursor of nitric oxide (NO), could reduce HTL (30 mM)-induced inhibition of EDR. After pretreatment with not only the NO synthase inhibitor Nomega-nitro-l-arginine methyl ester (L-NAME, 0.01 mM) but also the free sulfhydryl group blocking agent p-hydroxymercurybenzoate (PHMB, 0.05 mM) could abolish the protection of captopril and N-acetylcysteine, respectively. These results suggest that mechanisms of endothelial dysfunction induced by HTL may include the decrease of NO and the generation of oxygen free radicals and that captopril can restore the inhibition of EDR induced by HTL in isolated rat aorta, which may be related to scavenging oxygen free radicals and may be sulfhydryl-dependent.     

Crocetin improves endothelium-dependent relaxation of thoracic aorta in hypercholesterolemic rabbit by increasing eNOS activity

Our previous studies have proven that crocetin (CCT), extracted from Gardenia jasminoides Ellis, possesses the anti-atherosclerotic effect. Because endothelial dysfunction strongly contributes to the initiation and progression of atherosclerosis, the present study aims to investigate whether CCT is capable of improving this dysfunction and to explore the possible mechanisms. Endothelial dysfunction was induced by in vivo feeding high cholesterol diet (HCD) to rabbit and by in vitro treating bovine aortic endothelial cells (BAECs) with oxidized LDL (oxLDL). Endothelium-dependent relaxation (EDR) evoked by acetylcholine (Ach) and endothelium-independent relaxation (RIDR) mediated by sodium nitroprusside (SNP) of thoracic aorta isolated from rabbit were measured. The results indicated that the EDR in HCD alone treated rabbits was seriously impaired and the maximal relaxation induced by Ach (10(-5.5) M) was only 54% that in control rabbit fed with regular diet. Oral complementation with CCT (15, 30 mg/kg) dose-dependently improved this impairment and restored the maximal relaxation to 68% and 80% that in control group, respectively. However, the EIDR maintained comparable in all groups. Complementation with CCT (15, 30 mg/kg) simultaneously increased serum level of nitric oxide (NO), upregulated vessel activity and mRNA expression of endothelial NO synthase (eNOS) as well as vessel cyclic GMP (cGMP) content compared with those in rabbit treated with HCD alone. Inducible NOS (iNOS) activity remained unchangeable in all groups. In BAECs, oxLDL treatment decreased NO production, downregulated both activity and mRNA expression of eNOS. While those decrease or downregulation were inhibited by co-treatment with CCT (0.1, 1, 10 microM) in a dose-dependent manner. These findings suggested that CCT significantly restored the EDR of thoracic aorta in hypercholesterolemic rabbit, which might be explained by its action to increase the vessel eNOS activity, leading to elevation of NO production.     

代谢综合征大鼠胰岛素敏感性低下高血压和氧化应激及卡托普利干预作用

目的观察卡托普利(Cap)对代谢综合征(MetS)大鼠胰岛素敏感性及血压、肾素-血管紧张系统、一氧化氮(NO)及其合成、血糖和血脂以及氧化应激作用。方法Sprague-Dawley大鼠,雌雄各半,建立MetS大鼠模型;将病鼠随机分为模型对照、模型Cap 7mg/kg;3组大鼠分别肌肉注射消毒溶媒或药物,每日1次×4周;测定大鼠血压、空腹血糖(FBG)和口服糖耐量试验2h血糖(OGTT-2hBG)及血浆空腹胰岛素(FIns),血浆血糖含量(FPG),并计算胰岛素敏感指数(ISI),测血清甘油三酯(TG)、总胆固醇(TC)、低密度脂蛋白胆固醇(LDL-C)、高密度脂蛋白胆固醇(HDL-C)、NO、肿瘤坏死因子(TNF)-α、肾素和血管紧张素含量和一氧化氮合酶(NOS)、诱导型NOS(iNOS)和超氧化物岐化酶(SOD)活性。结果与正常对照组比较,MetS大鼠血压升高、FBG和OGTT-2 hBG、FPG和FIns含量增高,ISI减弱,血清TG、TC、TNF-α和肾素、血管紧张素含量增高(P<0.05)。经Cap处理MetS大鼠后,血压降低(P<0.01),FPG,FBG,OGTT-2hBG降低和IGT改善(P<0.05),纠正高胰岛素血症(P<0.05),增强ISI(P<0.05),降低TG、TC、NO和丙二醛(MDA)含量,抑制NOS和iNOS活性,提高SOD活性(P<0.05),下调血管紧张素和TNF-α含量(P<0.05);但比较LDL-C,HDL-C和肾素含量,差异无统计学意义(P>0.05)。结论Cap对抗MetS大鼠胰岛素抵抗、增强胰岛素敏感性、纠正高胰岛素血症,降低血压、血糖和血脂,拮抗肾素、血管紧张素Ⅱ转换以及增强抗氧化作用。