Cx43 is involved in electrical remodeling of atrial myocytes through regulating L-type calcium current

AIM: To investigate whether the association of connexin 43(Cx43) and L-type calcium channel involved in the pathogenesis of atrial fibrillation (AF). METHODS: The biochemical assays and whole-cell patch-clamp technique were used to study the expression of Cx43 in human atrial tissue. The co-localization of Cx43 and L -type calcium channel, and the regulation of L-type calcium current in atrial myocytes were investigated. RESULTS: The expression of Cx43 at mRNA and protein levels was decreased in human atrial tissues of AF patients. In cultured atrium-derived myocytes (HL-1 cells), knockdown of Cx43 significantly inhibited the mRNA expression of L-type calcium channel α1c subunit, as well as L-type calcium current. Co-localization of Cx43 with L-type calcium channel α1c subunit in mouse atrial myocytes was observed. CONCLUSION: The decrease in Cx43 is involved in the pathogenesis of AF, probably through reducing the L-type calcium current in atrial myoctyes by co-localization with L-type calcium channel, thus representing the potential pathogenesis in atrial fibrillation.     

皖麦43生物学特性和栽培技术

皖麦 43(皖 92 31 8)系安徽省农科院作物所选育的小麦新品种 ,春性 ,一般单产 6 0 0 0～ 6 75 0kg/hm2 ,适于沿淮、江淮地区中上等肥力水平的地块种植。株高 80～ 90cm ,长芒、白壳、白粒、半角质 ,千粒重 40g左右。籽粒蛋白质含量达 15 %以上 ,品质较好。对赤霉病抗 (耐 )性强 ,熟期转色好 ,不早衰。适宜播种期为 10月中、下旬至 11月初。基本苗可掌握在 2 40万～ 2 70万 /hm2 左右     

Effects of adiponectin on expression of connexin 43 in rat myocardium during ischemia-reperfusion

AIM: To observe the effects of adiponectin(APN) on the expression of connexin 43 (Cx43) in rat myocardium during ischemia-induced arrhythmias. METHODS: The SD rats were randomly divided into 4 groups (n=12): sham operation group (SM group), ischemia and reperfusion group (I/R group), I/R+adiponectin(APN1) group: pre-ischemia with 3.5 μg/kg of APN; I/R+APN2 group: post-ischemia with 3.5 μg/kg of APN. The incidence of ventricular arrhythmias and ventricular arrhythmia score (VAS) were determined. The expression of Cx43 in the ischemic myocardium was studied by the techniques of immunohistochemistry and RT-PCR. The levels of malondialdehyde(MDA) and superoxide dismutase(SOD) were measured by the methods of xanthine oxidase and thiobarbituric acid. The expression of endothelial nitric oxide synthase (eNOS) at mRNA and protein levels was determined by RT-PCR and Western blotting,respectively.The morphological changes of the myocardial tissues were observed under electronic microscope. RESULTS: The VAS and concentration of MDA increased obviously and the activity of SOD was decreased in I/R group as compared with SM group (P<0.01). The expression of Cx43 was evidently decreased and the distribution of Cx43 in the myocardium was disturbed. The expression of eNOS at mRNA and protein levels was decreased in I/R group (P<0.05). The ultrastructure of ventricular myocardium was abnormal in I/R group. Compared with I/R group, APN obviously decreased the VAS caused by ischemia and reperfusion (P<0.01) no matter the drug was given before or after ischemia. APN increased the activity of SOD, inhibited the MDA content in serum, and resulted in normal distribution of Cx43 and increased the expression of Cx43 and eNOS. Compared with I/R group, the changes of heart ultrastructure attenuated greatly in APN group, but didn't recover to normal state. CONCLUSION: Adiponectin antagonizes the arrhythmias during myocardial ischemia and reperfusion via inhibiting oxidative stress and regulating Cx43.     

白肉灵芝水提物对脑缺血大鼠海马神经元的保护作用

试验旨在探讨白肉灵芝水提物（Ganoderma leucocontextum aqueous extracts,GLAE）对脑缺血后海马神经元的保护作用及机制。将50只健康大鼠分为对照组、模型组、GLAE低（0.05 mg/（g·BW））、中（0.1 mg/（g·BW））、高（0.2 mg/（g·BW））剂量组。利用双侧颈总动脉夹闭法建立大鼠脑缺血模型,GLAE组灌胃不同剂量的GLAE干预,对照组和模型组灌胃同体积的生理盐水,连续2周。用跳台试验方法检测记忆获得、记忆巩固和记忆再现障碍大鼠的学习记忆能力,HE染色观察大鼠海马组织的病理形态的变化,比色法检测海马组织一氧化氮合酶（nitric oxide synthase,NOS）活性和一氧化氮（nitric oxide,NO）含量,Western blotting和实时荧光定量PCR法分别检测海马组织生长相关蛋白-43（growth associated protein-43,GAP-43）和脑源性神经生长因子（brain derived neurotrophic factor,BDNF）的水平。结果显示,与对照组相比,模型组大鼠跳台试验的逃避潜伏期显著缩短、电击次数显著增加（P<0.05）;海马神经元细胞出现明显核固缩、排列松散紊乱等退行性改变,细胞数量显著减少（P<0.05）;海马组织NOS活性和NO含量均显著降低（P<0.05）;大鼠海马组织GAP-43蛋白表达量显著升高（P<0.05）;海马组织BDNF mRNA表达量显著下调（P<0.05）。与模型组相比,GLAE干预后,大鼠逃避潜伏期均显著延长、电击次数均显著减少（P<0.05）;GLAE高剂量组大鼠CA1区和齿状回锥体神经元细胞形态明显改善,神经元数量显著增加（P<0.05）;GLAE低剂量组对NOS活性影响不明显（P>0.05）,显著增加NO含量（P<0.05）,GLAE中、高剂量组NOS活性和NO含量均显著升高（P<0.05）;GLAE低、中、高剂量组海马组织GAP-43蛋白表达量均显著增加（P<0.05）;GLAE低、中、高剂量组海马组织BDNF mRNA表达量均显著增加（P<0.05）。以上结果表明,GLAE可通过提高NOS活性和NO水平、促进海马神经发生和功能恢复对脑缺血后海马神经元损伤有一定的保护作用,从而改善大鼠认知功能,0.2 mg/g GLAE效果最好。     

联苯肼酯43%悬浮剂防治温室蔬菜叶螨田间药效试验示范

近几年来,随着温室水肥一体化技术的应用,温室内高温低湿的环境使得叶螨危害越来越重,给温室蔬菜生产带来很大的损失。在无公害蔬菜生产中,我们选用了低毒、对螨的各个阶段均有效的新型杀螨剂—联苯肼酯43%悬浮剂做试验示范。试验示范结果显示:联苯肼酯43%悬浮剂稀释3 000倍液在温室蔬菜—黄瓜、辣椒上使用效果显著。施药期间注意观察蔬菜叶螨发生危害动态,在叶螨发生始期进行防治,可有效控制叶螨蔓延危害。     

MB43活疫苗免疫效果及对鸡法氏囊组织操作的研究

本试验对鸡传染性法氏囊病（IBD）MB43活疫苗免疫后鸡的囊体比、新城疫血凝抑制（ND-HI）抗体效价及IBD AGP效价进行检测。结果表明，含有IBD高母抗试验鸡在17日龄免疫MB43活疫苗后，囊组织有不同程度的损伤；对正常免疫的ND-HI抗体效价无影响；试验鸡16天后IBD AGP阳性率为100%；21天攻毒保护率100%。     

紫云英类受体蛋白激酶Nip43靶蛋白的筛选与初步鉴定

以紫云英类受体蛋白激酶Nip43的S-TKs结构域构建诱饵载体,通过酵母双杂交技术,筛选获得17个候选的阳性克隆。经过测序分析和Blast比对,最终确定了1个互作蛋白EPN。EPN蛋白是网格蛋白聚合反应中的配体蛋白,可调控网格蛋白的聚合反应。通过实验验证显示,靶蛋白EPN与Nip43蛋白互作最强的区域为ENTH/ANTH结构域。Real-time q PCR检测表明,epn基因参与了根瘤菌早期结瘤过程。     

Effects of metoprolol on phosphorylated connexin 43 expression in myocardial tissues and apoptosis of myocardial cells in heart failure rats

AIM：To explore the in vivo effects of metoprolol on the expression of phosphorylated connexin 43 (p-Cx43) in myocardial tissues and the apoptosis of myocardial cells in rats with heart failure (HF).METHODS：One hundred Sprague-Dawley rats were randomly divided into 5 groups (each n=20): sham group, HF group, low-dose (1.25 mg·kg-1·d-1) metoprolol treatment (MetoA) group, middle-dose (5 mg·kg-1·d-1) metoprolol treatment (MetoB) group and high-dose (20 mg·kg-1·d-1) metoprolol treatment (MetoC) group.The rats in HF group and metoprolol treatment groups were subject to abdominal aortic ligation, and different doses of metoprolol were given 4 weeks later till 8 weeks after operation.Echocardiography was conducted to monitor the hemodynamic parameters at the 4th and 8th weeks, and the rat hearts were taken at the 8th week after operation.The morphological changes and the proliferation of collagen fibers in myocardial tissues were observed by HE and Masson staining, respectively.The expression level of p-Cx43 was detected by Western blotting and the apoptosis of myocardial cells was assessed by TUNEL method.The relationship between p-Cx43 expression level and apoptotic index was analyzed by Pearson’s correlation.RESULTS：(1) Echocardiography showed that metoprolol could effectively improved cardiac hemodynamics in HF rats, and pathological findings suggested that metoprolol could effectively reverse HF-induced cardiac remodeling in a dose-dependent manner within the therapeutic dose range.(2) Western blotting showed that p-Cx43 expression in HF group was significantly higher than that in sham group (P<001), and that in all metoprolol treatment groups was significantly decreased compared with HF group (P<005 or P<001), among which pairwise comparisons also showed significant differences (P<001).(3) The myocardial apoptotic index in HF group ［(51.17±6.94)%］ was significantly increased compared with sham group ［(4.62±160)%, P<001］.Compared with HF group, myocardial apoptotic indexes in MetoA group ［(40.60±4.15)%］, MetoB group ［(30.66±4.00)%］ and MetoC group ［(22.24±5.69)%］ were significantly decreased (P<001), among which pairwise comparisons also showed significant differences (P<001).(4) The expression level of p-Cx43 was positively correlated with the apoptotic index (r=0.905, P<001).CONCLUSION: The mechanism of metoprolol against HF-induced myocardial apoptosis may be related to inhibition of p-Cx43 expression.     

贵州草海湿地农田沟渠沉积物氮磷的吸附动力学及影响因素

以草海-湿地农田沟渠系统为研究对象,运用模拟实验的方法,针对沟渠系统对氮磷的截留效用、沟渠沉积物对氮磷的吸附动力学及其影响因素进行了研究。结果表明,湿地农田沟渠系统对TP和TN的截留率分别为66.7%～79.7%和66.0%～76.4%,对NH4＋-N的截留率最高,为82.8%～89.3%。沟渠沉积物与太湖、滇池沉积物相比较而言,沉积物对PO4-3-P和NH4＋-N吸附平衡时间较长。盐度、[SO42-]和[NO3-]对PO43--P和NH4＋-N的吸附都具有一定的抑制作用;而[Ca2＋]对两者的影响具有明显的差别：Ca^2＋对PO43--P的吸附在低浓度下抑制,在高浓度下有促进作用;对NH4＋-N的吸附具有明显的抑制作用,且当[Ca^2＋]浓度为5mg·L^-1时吸附量最小。