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排序方式: 共有3482条查询结果,搜索用时 15 毫秒
1.
电损毁海马CA3区及连合前穹窿对大鼠血浆胰岛素水平... 总被引:1,自引:0,他引:1
Bilateral electrical lesioning of the hippocampal CA3 region (HCA3-EL) or anterior commissura hippocampi (ACHF-EL) caused marked elevations in plasma basal levels of insulin. 2 weeks later, fasting blood glucose levels were also augmented with decreased glucose tolerance. In contrast, the secretory response of pancreatic B cells to glucose stimulation was markedly enhanced. Following intravenous glucose tolerance test (IVGTT), the relative amounts of glucagon-like and insulin-like immunoreactants were reduced in the pancreatic islets of both HCA3-EL and ACHF-EL rats in comparison with the controls. In the HCA3-EL group, the relative amounts of somatostatin-like immunoreactants and gross numbers of such immunostained cells in islets were also decreased as compared with the control. No difference was seen in pancreatic-polypeptide-like immunoreactivities as assessed by immunohistochemistry plus microphotometry method. The above results suggest strongly that HCA3 and ACHF exert a tonic inhibitory action on the insulin secretion in the rat. 相似文献
2.
利用大鼠肝脏线粒体为材料,以琥珀酸为底物,研究了不同浓度的丹参酮Ⅱ-A磺酸钠对线粒体态4、态3呼吸及呼吸控制率,线粒体跨膜电位,线粒体呼吸链复合体(Ⅱ+Ⅲ)电子传递及质子转移活性的影响。结果证明丹参酮ⅡA-磺酸钠是线粒体呼吸链复合体(Ⅱ+Ⅲ)的有效抑制剂。文中对丹参酮ⅡA-磺酸钠在心肌缺血再灌注过程中的保护作用的分子机理进行了讨论。 相似文献
3.
氯化镧对玉米根切段钾离子外渗影响的动力学研究 总被引:9,自引:0,他引:9
研究了氯化镧对玉米(Zea mays L.)“京早8号”根切段细胞膜透性及质子分泌的影响,并用动力学方法研究了钾离子外渗过程的变化。氯化镧处理可降低外渗液的电导率及K~ 和糖的外渗量,使质子分泌活动增强。用动力学方法分析玉米根切段K~ 外渗过程的结果表明:(1)应用于K~ 吸收研究的数学模型也能适应于K~ 外渗的研究;(2)在LaCl_3和(或)CaCl_2存在的条件下,最大吸收速度(V_(max))升高,而米氏常数(K_m)没有变化;(3)在LaCl_3和(或)CaCl_2存在的条件下,K~ 外渗量降低是由于最大吸收速度(V_(max))升高所致。 相似文献
4.
盐或低温胁迫对花生幼苗下胚轴ATP酶和质膜中PIP2含量的影响 总被引:2,自引:0,他引:2
经6%-12%Dextran T70密度梯度离心,获得了纯度较高的7d龄花生幼苗下胚轴质膜和液泡膜制剂。150mmol/L NaCl或10℃低温处理花生幼苗24h,其下胚轴质膜上的Mg^2+激活的ATPase活性分别提高了37.6%和17.2%;Ca^2+-ATPase活性分别提高45.8%和33.6%。上述盐或低温处理也提高了液泡膜上Mg^2+激活的ATPase活性,分别为对照的141.2%和1 相似文献
5.
The simple design of traditional spinner flasks makes the on-line estimation of cellular metabolism impossible. An on-line estimation system has been developed and used for the monitoring of oxygen uptake rate (OUR) for insect cells growing in a modified spinner flask. Neglect of oxygen desorption from culture media is a common source of error in OUR measurements for Sf21 cells. Therefore, an algorithm was developed to compensate for the affect of such desorption process on the determination of OUR. A modified spinner flask was successfully used as a low-volume bioreactor for insect cell cultivation and the OUR measurement developed here is both convenient and reliable. 相似文献
6.
本文首次报道了五步蛇身体主要部位的数量性状与其排毒量的关系。其中我们发现与排毒量有关的部位是头积、体粗、体重、佛指长。 相似文献
7.
From ten genera and 146 bacterial strains, 22 strains producing alpha-amino acid ester hydrolase were selected. Among them, AS 1.586 and 41-2 were the best. The optimal conditions for synthesis of cephalexin by pseudomonas aeruginosa 1.204 were investigated. The optimal pH and temperature for enzymatic synthesis reaction was pH 6.8 and 25 degrees C, respectively. By using 1% 7-ADCA, 3% PGME and 4% biomass, about 70% of 7-ADCA was converted to cephalexin under the mentioned conditions. 相似文献
8.
ChunMei Yin JunJiao Li Dan Wang DanDan Zhang Jian Song ZhiQiang Kong BaoLi Wang XiaoPing Hu Steven J. Klosterman Krishna V. Subbarao JieYin Chen XiaoFeng Dai 《Molecular Plant Pathology》2022,23(8):1122
The arms race between fungal pathogens and plant hosts involves recognition of fungal effectors to induce host immunity. Although various fungal effectors have been identified, the effector functions of ribonucleases are largely unknown. Herein, we identified a ribonuclease secreted by Verticillium dahliae (VdRTX1) that translocates into the plant nucleus to modulate immunity. The activity of VdRTX1 causes hypersensitive response (HR)‐related cell death in Nicotiana benthamiana and cotton. VdRTX1 possesses a signal peptide but is unlikely to be an apoplastic effector because its nuclear localization in the plant is necessary for cell death induction. Knockout of VdRTX1 significantly enhanced V. dahliae virulence on tobacco while V. dahliae employs the known suppressor VdCBM1 to escape the immunity induced by VdRTX1. VdRTX1 homologs are widely distributed in fungi but transient expression of 24 homologs from other fungi did not yield cell death induction, suggesting that this function is specific to the VdRTX1 in V. dahliae. Expression of site‐directed mutants of VdRTX1 in N. benthamiana leaves revealed conserved ligand‐binding sites that are important for VdRTX1 function in inducing cell death. Thus, VdRTX1 functions as a unique HR‐inducing effector in V. dahliae that contributes to the activation of plant immunity. 相似文献
9.
10.
基于Sf21昆虫细胞在悬浮培养过程中所表现出的生长代谢特征,提出以培养液中残糖浓度作为控制参数,并利用限制性基质(葡萄糖和蛋白水解物)的间歇补加技术调控细胞生长的方案。实际控制表明:与批培养相比,Sf21细胞在两种具代表性的昆虫细胞培养基(IPL-41和TC-100)中的生长期和稳定期都得到了有效的延长。TC-100培养液中最高细胞培养密度由3.0×106 cells/mL提高到6.5×106 cells/mL;IPL41培养液中最高细胞培养密度则由7.05×106 cells/mL提高到9.0×106cells/mL。由于限制性基质的间歇补加技术是利用较确定的营养成分来代替复杂昂贵的补料培养基,因此更适合于昆虫细胞的大规模高密度培养。 相似文献