氯氨酮和L-NAME抑制模拟高原低氧大鼠下丘脑NOS和生长抑素mRNA的表达

用高原低氧模型及原位杂交、ＮＡＤＰＨ－ｄ组织化学法,探讨氯氨酮和Ｌ－ＮＡＭＥ对急性高原低氧大鼠下丘脑一氧化氮合酶（ＮＯＳ）和生长抑素ｍＲＮＡ（ＳＳ ｍＲＮＡ）表达的影响。结果表明,急性高原低氧引起下丘脑ＮＯＳ和ＳＳ ｍＲＮＡ过度表达,如先用ＮＭＤＡ受体拮抗剂氯氨酮和ＮＯＳ抑制剂Ｌ－ＮＡＭＥ预处理,ＮＯＳ和ＳＳ ｍＲＮＡ的表达均明显被抑制。结果提示,ＮＭＤＡ受体参与了急生高原低氧引起的下丘脑ＮＯＳ和     

烫伤对大鼠下丘脑视上核内皮素-1基因转录和蛋白含量的影响

用原位杂交和免疫组织化学方法观察了烫伤后下丘脑视上核（ＳＯＮ）内皮素－１（ＥＴ－１）基因转录和蛋白含量的变化,并用通用图像颗粒分析法估计ＥＴ－１ ｍＲＮＡ阳性杂交信号的强度和ＥＴ－１样免疫反应物（ＥＴ－１－ｉｒ）的免疫反应强度。与对照组相比,烫伤后１５ｍｉｎ,ＳＯＮ神经元胞浆内ＥＴ－１ ｍＲＮＡ阳性杂交信号未见明显变化;而在烫伤后６０和１８０ｍｉｎ,ＥＴ－１ ｍＲＮＡ阳性杂交信号强度分别较比照组增     

外周炎性刺激条件下大鼠脊髓背角PPE mRNA及L-ENK样品和μ阿片受体样阳性结构的变化

以鹿角菜胶（ＣＡＲ）注射到大鼠一侧后爪的足底皮下作为伤害性刺激模型,分别于ＣＡＲ刺激后６、１２ｈ和１、３ｄ处死动物,对照组动物仅将盐水注入一侧后爪足底皮下,用原位杂交法和免疫组织化学法观察前原脑啡肽（ＰＰＥ）ｍＲＮＡ阳性神经元、亮氨酸脑啡肽（Ｌ－ＥＮＫ）和μ阿片受体（ＭＯＲ）样阳性结构在大鼠脊髓背角（ＳＤＨ）的分布和变化。对照组大鼠ＳＤＨ内可见到大量ＰＰＥｍＲＮＡ阳性神经元,这些阳性神经元主要分布于Ⅰ、Ⅱ层和Ⅴ、Ⅵ层,ＣＡＲ刺激后６ｈ,刺激侧ＳＤＨ中ＰＰＥｍＲＮＡ阳性神经元的数量明显增多,１２ｈ和１ｄ达到最高水平,３ｄ时略有下降,但仍高于正常水平。Ｌ－ＥＮＫ样阳性纤维和终末主要分布于正常大鼠ＳＤＨ的Ⅰ、Ⅱ层,ＣＡＲ刺激后１ｄ,Ｌ－ＥＮＫ样阳性结构在刺激侧ＳＤＨ中的密度略有升高,３ｄ后下降直至低于正常水平。ＭＯＲ阳性胞体和纤维主要分布于ＳＤＨ的Ⅱ层,ＣＡＲ刺激后１ｄ,刺激侧Ⅱ层中ＭＯＲ阳性结构明显增加,并持续到刺激后３ｄ。上述结果提示阿片类物质在伤害性信息调控中具有重要作用。     

NO对大鼠睡眠-觉醒的调节

目的和方法：通过对大鼠侧脑室微量注射ＮＯＳ抑制剂Ｌ－ＮＡＭＥ及ＮＯ的前体Ｌ－精氨酸（Ｌ－Ａｒｇ）观察两种物质对大鼠睡眠－觉醒的影响。结果：注射１ｍｇ Ｌ－ＮＡＭＥ（５μＬ）后４ｈ觉醒（Ｗ）明显增加,尤以注射后第１￣２ｈ显著;４ｈ慢波睡眠（ＳＷＳ）明显减少,该效应同样以注射后第１￣２ｈ显著;异相睡眠（ＰＳ）无明显变化。小剂量Ｌ－ＮＡＭＥ（０．２ｍｇ,５μｌ）对大鼠的Ｗ、ＳＷＳ、ＰＳ无明显影响;同样方     

mRNA很可能携带三维遗传信息(英文)

ｍＲＮＡ很可能携带三维遗传信息ＭＥＳＳＥＮＧＥＲＲＮＡＰＲＯＢＡＢＬＹＣＡＲＲＩＥＳＴＨＥＴＨＲＥＥ－ＤＩＭＥＮＳＩＯＮＡＬＧＥＮＥＴＩＣＩＮＦＯＲＭＡＴＩＯＮＴｈｅｆｏｒｍｉｎｇｍｅｃｈａｎｉｓｍｏｆｔｈｅｔｈｒｅｅ－ｄｉｍｅｎｓｉｏｎａｌｓｔｒｕ...     

一氧化氮抑制内皮素促血管平滑肌细胞增殖作用的信号转导途径

培养的家兔胸主动脉血管平滑肌细胞（ＶＳＭＣ）分别以内皮素（ＥＴ－１）、一氧化氮（ＮＯ）前体Ｌ－Ａｒｇ和ＮＯ供体ＳＩＮ－１刺激,或用ＥＴ－１＋Ｌ－Ａｒｇ、ＥＴ－１＋ＳＩＮ－１联合刺激,测ＶＳＭＣ＾３Ｈ－ＴｄＲ掺入、丝裂素活化蛋白激酶（ＭＡＰＫ）活性及蛋白激酶Ｃ（ＰＫＣ）活性的改变,以研究ＮＯ抑制ＥＴ－１促ＶＳＭＣ增殖作用的信号转导途径。结果表明：（１）ＥＴ－１ １０＾－８ｍｏｌ／Ｌ单独刺激,＾３Ｈ－     

植物胚胎发育后期富集(LEA)蛋白的研究进展

植物胚胎发育后期富集（ＬＥＡ）蛋白的研究进展汤学军傅家瑞（中山大学生命科学学院,广州５１０２７５）ＰＲＯＧＲＥＳＳＯＦＴＨＥＳＴＵＤＹＯＮＬＡＴＥＥＭＢＲＹＯＧＥＮＥＳＩＳＡＢＵＮＤＡＮＴ（ＬＥＡ）ＰＲＯＴＥＩＮＳＩＮＰＬＡＮＴＳＴａｎｇＸｕｅ－Ｊ...     

披针叶胡颓子果实营养成分的测定

披针叶胡颓子果实营养成分的测定毛学文（天水师范高等专科学校,天水７４１０００）ＤＥＴＥＲＭＩＮＡＴＩＯＮＯＦＮＵＴＲＩＥＮＴＣＯＮＳＴＩＴＵＥＮＴＳＩＮＳＥＥＤＳＯＦＥＬＡＥＡＧＮＵＳＬＡＮＣＥＯＬＡＴＡＭａｏＸｕｅ－ｗｅｎ（ＴｉａｎＳｈｕｉＴｅａｃ...     

人Mn—SOD cDNA的克隆及高效表达

用逆转录－聚合酶链反应（ＲＴ－ＰＣＲ）,以人肝细胞株（Ｌ０２）总ＲＮＡ为模板,扩增了人锰超氧化物歧化酶（ｈＭｎ－ＳＯＤ）的ｃＤＮＡ。重组到Ｔ７启动子控制下的表达载体ｐＥＴ－２４ａ（＋）中,构建表爱质粒ｐＥＴ－ＭｎＳＯＤ,并转化大肠杆菌ＢＬ２１（ＤＥ３）。ＳＤＳ－ＰＡＧＥ及蛋白质印迹分析表明,经１ｍｍｏｌ／Ｌ异丙基硫代－β－Ｄ－半乳糖苷（ＩＰＴＧ）诱导后,可高效表达一分子量为２２ｋＤ的蛋白质,与抗人     

池塘养殖环境中底质－水界面营养盐扩散通量的现场测定

池塘养殖环境中底质－水界面营养盐扩散通量的现场测定ＦＩＥＬＤＤＥＴＥＲＭＩＮＡＴＩＯＮＯＦＤＩＦＦＵＳＩＯＮＦＬＵＸＯＦＮＵＴＲＩＥＮＴＳＦＲＯＭＳＥＤＩＭＥＮＴ－ＷＡＴＥＲＩＮＴＥＲＦＡＣＥＯＦＣＵＬＴＵＲＥＰＯＮＤ￥ＳｕｎＹａｏ（ＹｅｌｌｏｗＳｅ...     

Effects of ghrelin on Cx43 regulation and electrical remodeling after myocardial infarction in rats

Ghrelin is a novel growth hormone-releasing peptide, which has been shown to exert beneficial effects on ventricular remodeling. In this study, we investigated whether ghrelin could decrease vulnerability to ventricular arrhythmias in rats with myocardial infarction and the possible mechanism. Twenty-four hours after ligation of the anterior descending artery, adult male Sprague-Dawley rats were randomized to ghrelin (100 μg/kg) and saline (control group) for 4 weeks. Sham animals underwent thoracotomy and pericardiotomy, but not LAD ligation. Myocardial endothelin-1 (ET-1) levels were significantly elevated in saline-treated rats at the border zone compared with sham-operated rats. Myocardial connexin43 (Cx43) expression at the border zone was significantly decreased in saline-treated infarcted rats compared with sham-operated rats. Ghrelin significantly decreased the inducibility of ventricular tachyarrhythmias compared with control group. Arrhythmias sores during programmed stimulation in saline-treated rats were significantly higher than scores in those treated with ghrelin. The electrophysiological improvement of fatal ventricular tachyarrhythmias was accompanied with increased immunofluorescence-stained Cx43, myocardial Cx43 protein and mRNA levels in ghrelin treated rats. We also shown that ghrelin significantly decreased tissue ET-1 levels at the infarcted border zone. Thus, ghrelin showed the protective effect on ventricular arrhythmias after myocardial infarction. Although the precise mechanism by which ghrelin modulates the dephosphorylation of Cx43 remains unknown, it is most likely that the ghrelin increased expression of Cx43 through the inhibition of ET-1.     

Endothelin-converting enzyme-1 expression in acute and chronic liver injury in fibrogenesis

Endothelin-1 (ET-1) induces contraction, proliferation, and collagen synthesis of activated hepatic stellate cells and is a potent mediator of portal hypertension. Endothelin-converting enzyme-1 (ECE-1) generates ET-1 from the inactive precursor big-endothelin-1. The cellular distribution and activity of ECE-1 in the liver is unknown. Hepatic fibrogenesis was induced in rats by CCl₄ administration and secondary biliary cirrhosis after 6 weeks of complete bile duct occlusion (BDO). The tissue ET-1 and ET receptor protein levels were quantified, the ECE-1 isoform mRNAs were measured by RNase protection assay and ECE-1 activity was analyzed. ECE-1a and -b mRNA were upregulated in biliary cirrhosis and in CCl₄-injured livers, whereas ECE-1c mRNA remained unchanged. ECE-1 activity was increased after BDO and peaked at 12?h after acute CCl₄-intoxication. Tissue levels of ET-1, ET_A- and ET_B receptors were elevated 7-, 5-, and 4.6-fold in cirrhotic rats, respectively. ECE-1 activity increased following BDO and acute CCl₄-intoxication. In conclusion, ECE-1a and -b RNAs are upregulated in fibrogenesis, indicating that these isoforms play a central role in ET-1 generation during fibrogenesis and portal hypertension.     

Endothelin-1 contributes to the sexual differences in renal damage in DOCA-salt rats

We investigated whether gender differences in renal damage in DOCA-salt hypertension are associated with effects of ovarian hormones and/or endothelin-1 (ET-1). Renal injuries and renal pre-pro-ET-1 mRNA expression were enhanced in male and female ovariectomized (OVX) DOCA rats versus female DOCA rats. Treatment with estrogen plus progesterone or progesterone, but not estrogen alone, attenuated renal damage and pre-pro-ET-1 mRNA expression in OVX DOCA rats. The ETA antagonist BMS182874 greatly ameliorated renal damage in male and OVX DOCA rats. In conclusion, the ovarian hormones have a protective role on the renal structural alterations in female DOCA rats by modulating effects of ET-1, via ETA receptors.     

Arrhythmogenic action of endothelin-1(1-31) through conversion to endothelin-1(1-21)

Endothelin (ET)-1(1-21) is known to play an important role in the pathogenesis of acute ischemic arrhythmia. In the present study, we attempted to determine whether administration of ET-1(1-31) would result in arrhythmia in perfused isolated rat hearts. Forty-eight Sprague-Dawley rats weighing approximately 250-350 g were randomized into 6 groups. Heart was isolated and perfused in a Langendorff mode. The effects of ET-1(1-31) on arrhythmia, heart rate, coronary flow, and heart function were analyzed. Perfusion with 1 nM ET-1(1-31) resulted in frequent ventricular ectopic beats (VEBs) and ventricular tachycardia (VT). Overall VEB was 128.0 (approximately 66.0-1015.0), and the arrhythmia score (AS) was 2.18 +/- 0.87; both were significantly higher than those of the control group (P < 0.01). Pretreatment with perfusion of 10 nM of the ETA-receptor antagonist BQ(123) markedly attenuated the occurrence of VEB and VT induced by ET-1(1-31). AS in 10 nM BQ123 group was significantly lower than that in 1 nM ET-1(1-31) group (P < 0.01). The arrhythmia induced by 1 nM ET-1(1-31) was partially but significantly reduced by phosphoramidon (1 microM), a neutral endopeptidase/ET-converting enzyme inhibitor. ET-1(1-31) per se caused arrhythmia in perfused isolated rat hearts. This arrhythmogenic action is in part mediated by ET(A) receptor and may be attributed mainly to the conversion of ET-1(1-31) to ET-1(1-21.).     

Effect of eicosapentaenoic acid on the different endothelin system components in endothelin-1-induced hypertrophied cardiomyocytes

The cardiovascular benefit of fish oil, including eicosapentaenoic acid (EPA), in humans and experimental animals has been reported. The role of endothelin-1 (ET-1) in cardiac hypertrophy is well known. Endothelin-1 stimulates prepro-ET-1 mRNA expression in cardiomyocytes, and the autocrine/paracrine system of ET-1 is important for cardiomyocyte hypertrophy. Although many studies link EPA to cardiac protection, the effect of EPA on cardiac hypertrophy has yet to be clarified. Recently, we demonstrated that ET-1-induced cardiomyocytic change could be prevented by pretreatment with EPA. The present study investigated the changes of different components of the ET system at the mRNA level in ET-1-administered cardiomyocytes, and examined the effect of EPA pretreatment. Ventricular cardiomyocytes were isolated from 2-day-old Sprague-Dawley rats, cultured in Dulbecco's modified Eagle's medium and Ham F12 supplemented with 0.1% fatty acid-free bovine serum albumin for 3 days. At Day 4 of culture, the cardiomyocytes were divided into 3 groups: control group, ET-1-treated (0.1 nM) group, and ET-1-treated group pretreated with EPA (10 microM). Twenty-four hours after treatment, the gene expressions of different components of the endothelin system in three experimental groups were evaluated by real-time polymerase chain reaction. Prepro-ET-1 mRNA expression was 53% upregulated in ET-1-induced hypertrophied cardiomyocytes and suppressed in the EPA-pretreated group. Endothelin-converting enzyme-1 (ECE-1) was also increased in ET-1-administered cardiomyocytes by 42% compared with the control group and was reversed in the EPA-pretreated group. The two receptors of ET system, ET(A) and ET(B), tended to be increased in the ET-1-treated group, but no statistical significance was seen among study groups. Endothelin-1 increased prepro-ET-1 and ECE-1 mRNA expression in hypertrophied-neonatal cardiomyocytes, and this was reversed with EPA pretreatment. Thus, EPA may play a crucial role in the regression of ET-1-induced cardiomyocyte hypertrophy, partly through the suppression of ET-1 and ECE-1 expression.     

Endothelin-1 stimulates glial cell line-derived neurotrophic factor expression in cultured rat astrocytes

Effects of endothelin-1 (ET-1) on glial cell line-derived neurotrophic factor (GDNF) production in cultured astrocytes were examined. Treatment of cultured astrocytes with ET-1 (100 nM) increased mRNA levels of GDNF in 1-6h. The effect of ET-1 was inhibited by BQ788, an ET(B) receptor antagonist, but not by FR139317, an ET(A) receptor antagonist. ET-1 stimulated release of GDNF into culture medium. Dexamethasone (1 microM) and pyrrolidine dithiocarbamate (PDTC, 100 microM), which inhibit activation of NFkappaB, prevented the increases in GDNF mRNA by H(2)O(2). In contrast, the effect of ET-1 was not affected by dexamethasone and PDTC. The increase of astrocytic GDNF mRNA by ET-1 was inhibited by BAPTA/AM (30 microM) and PD98059 (50 microM), but not by calphostin C, staurosporine, and cyclosporine A. These results suggest that ET-1 stimulated expression of astrocytic GDNF through ET(B) receptor-mediated increases in cytosolic Ca(2+) and ERK activation.     

应激刺激对大鼠下丘脑血管升压素mRNA水平的影响

实验在给予慢性应激刺激的Ｓｐｒａｇｕｅ Ｄａｗｌａｙ雄性大鼠中进行,用核酸斑点杂交技术观察大鼠下丘脑组织中血管升压素（ＡＶＰ）ｍＲＮＡ水平变化,用异羟基洋地黄毒甙（ＤＩＧ）标记的２６个碱基长寡聚核苷酸作为检测探针。结果观察到：在给予电击足底结合噪声的应激刺激之后,尾动脉收缩压逐渐升高,到刺激第５天,刺激组与对照组动物之间尾动脉收缩压差别有统计学显著意义;到刺激第９天,刺激组尾动脉收缩压达最高值;以     

内皮素—1预处理大鼠心脏Gaq／11和Gia蛋白含量的变化

The present study was undertaken to explore the mechanism of G protein-mediated signal transduction pathway during endothelin-1 (ET-1) pre-treatment and ischemic preconditioning (IP). Rats were divided into four groups: ET-1, IP, ischaemia-reperfusion (IR) and control groups. ET-1 pre-treatment model was prepared by administrating 0.5 nmol/(L.kg) ET-1 into rat left ventricle, whereas IP model was prepared by ligating the left coronary artery for 5 min followed by 30 min reperfusion. All the animals were subjected to 60 min regional ischaemia and 30 min reperfusion alternately and then parameters of ventricular arrhythmia and expression of cardiac Galphaq/11 and Gialpha2 were measured. The results showed that the scores of ventricular arrhythmia decreased significantly in both ET-1 and IP treated groups as compared with IR group. In comparison with control group, Galphaq/11 increased by 77.8% (P<0.05) and 110.6% (P<0.01) in IP and ET-1 group respectively. Gialpha2 showed no significant difference in IP group, while it decreased by 31.0% (P<0.01) in ET-1 group. In conclusion, activation of G alphaq/11 may be related to the protecting mechanism of ET-1 pre-treatment and IP, whereas Gialpha2 may only play a role in ET-1 pre-treatment.     

Flow regulation of collecting duct endothelin-1 production

Collecting duct (CD) endothelin-1 (ET-1) is an important autocrine inhibitor of CD Na(+) reabsorption. Salt loading is thought to increase CD ET-1 production; however, definitive evidence of this, as well as understanding of the mechanisms transducing this effect, is lacking. Tubule fluid flow increases in response to Na(+) loading; hence, we studied flow modulation of CD ET-1 production. Three days of a high-salt diet increased mouse and rat inner medullary CD (IMCD) ET-1 mRNA expression. Acute furosemide infusion increased urinary ET-1 excretion in anesthetized rats. Primary cultures of mouse or rat IMCD detached in response to flow using a closed perfusion chamber, consequently a CD cell line (mpkCCDcl4) was examined. Flow increased ET-1 mRNA at shear stress rates exceeding 1 dyne/cm(2), with the maximal effect seen between 2 and 10 dyne/cm(2). Induction of ET-1 mRNA was first evident after 1 h, and most apparent after 2 h, of flow. Inhibition of calmodulin or dihydropyridine-sensitive Ca(2+) channels did not alter the flow response; however, chelation of intracellular Ca(2+) or removal of extracellular Ca(2+) largely prevented flow-stimulated ET-1 mRNA accumulation. Downregulation of protein kinase C (PKC) using phorbol 12-myristate 13-acetate, or PKC inhibition with calphostin C, markedly reduced flow-stimulated ET-1 mRNA levels. Flow-stimulated ET-1 mRNA accumulation was abolished by inhibition of phospholipase C (PLC). Taken together, these data indicate that flow increases CD ET-1 production and this is dependent on extracellular and intracellular Ca(2+), PKC, and PLC. These studies suggest a novel pathway for coupling alterations in extracellular fluid volume to CD ET-1 production and ultimately control of CD Na(+) reabsorption.