Cardiac L-type calcium channel and its alterations in cardiac hypertrophy and heart failure     

LIN Ji-jin  HUO Xia  DING Bao-chun 《园艺学报》2000,16(9):861-864

There are two type of cardiac calcium channel current, both are inward current: (1) L-type Ca²⁺channel current (I_ca-L), plays a major role in determining myocyte action potential plateau characteristics as well as initiating the myocyte excitation-contraction coupling; (2) T-type Ca²⁺ channel current (I_ca-T), probably plays an important role in pacemaker activity. The alterations of L-type calcium channel abundance and function in cardiac hypertrophy and heart failure are determined by the the species difference, especially by the stage of the disease process and the degree of the disease. Both abundance and function of L-type calcium channel decrease in severe hypertrophy and heart failure.  相似文献   

中国沙棘子叶叶肉细胞电流全细胞记录的研究     

朱俊英  闫慧  高荣孚  尹伟伦 《江西农业大学学报》2007,29(5):762-766

实验得出适合膜片钳实验的耐盐木本植物中国沙棘子叶原生质体的游离条件,即取当天脱壳的子叶,放入渗透浓度为0.88 mol/L,pH为5.8,酶液的组分为10 g/LCellulase R-10、0.5 g/LPectolyase Y-23、1.5 g/LMacrozymeR-10、1 g/L Hemicellulase、1 g/L BSA、1 g/L PVP-40、2 mmol/L CaCl2、10 mmol/L Mes和5 mmol/L Vc的溶液中,在26℃、黑暗条件下,静置4 h。并且利用Multiclamp 700B放大器和Clampex 9.2软件,记录到了该原生质体质膜全细胞内向K 通道电流(-459.137 pA及-290.527 pA)和非选择性阳离子通道的外向电流(8.036 pA)。这为沙棘属木本植物细胞的电生理特性及其耐盐性机制关系的研究奠定基础。  相似文献   

Effects of thyroid hormone on myocardial T-type calcium channels at mRNA and protein levels in rats     

FU Run-xi  YANG Ruo-song  HUANG Xue-qin  HE Wen-ming  YU You-yan  WEI Deng-ming 《园艺学报》2018,34(6):996-1001

AIM: To observe the effect of thyroxine on the expression of T-type calcium channels Cav3.1, Cav3.2 and Cav3.3 in rat myocardium, and to explore the possible biological mechanism between the changes of the expression of T-type calcium channels and the arrhythmia in hyperthyroid heart disease. METHODS: Healthy SD rats (n=20) were randomly divided into normal control group (n=10) and hyperthyroid heart disease group (n=10). The animal model was established by intraperitoneal injection of levothyroxine for 35 d. The contents of T3 and T4 in serum, the heart-to-body weight ratio, the diameter of cardiac myocytes and electrocardiograph were measured to evaluate hyperthyroid heart disease. Moreover, the mRNA and protein expression levels of T-type calcium channels in the myocardium were measured by RT-PCR, immunohistochemistry and Western blot. RESULTS: After intraperitoneal injection of levothyroxine for 35 d, compared with the normal control group, the serum contents of T3 and T4, the heart-to-body weight ratio and the diameter of cardiac myocytes were significantly increased in hyperthyroid heart disease group (P<0.05), and arrhythmia occurred in hyperthyroid heart disease group. By immunohistochemistry and Western blot, the protein expression of Cav3.1 increased significantly (P<0.05), while the protein expression of Cav3.2 decreased significantly (P<0.01). However, no change of the Cav3.3 protein was observed. The results of RT-PCR were the same as immunohistochemistry and Western blot. CONCLUSION: Thyroxine promotes the expression of Cav3.1 in the myocardium but inhibits the expression of Cav3.2 at mRNA and protein levels, which might be involved in arrhythmia in hyperthyroid heart disease.  相似文献   

八脉及其交会穴位在宠物临床上的应用     

邢玉娟  陈玉库  王建国  胡元亮  周浩良 《动物医学进展》2019,(5):109-114

八脉有督脉、任脉、冲脉、带脉、阴维脉、阳维脉、阴跷脉、阳跷脉,是别行奇道的经脉,具有统摄经脉气血、协调阴阳的作用。任督二脉穴位主治范围广泛,六条奇经虽无本经专属经穴,但其纵横交叉于十二经脉之间,往往一脉通多经。运用比较针灸方法,借鉴中医临床的研究成果和成熟经验,找寻出对某些疾病有特效的奇经八脉穴位/交会穴位,可扩大正经的主治范围,提高针灸的施治效果,以更好地防治犬、猫疾病。  相似文献   

Effects of cerebral ischemia reperfusion injury on L-type calcium channel in CA1 pyramidal neurons in hippocampus of adult rats     

TANG Yu  LUO Rong-jing  ZHONG Le-quan 《园艺学报》2008,24(5):1030-1031

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A test for competition between two Gobiomorphus species (Teleostei: Eleotridae) in artificial channels     

G. J. Glova 《Ecology of Freshwater Fish》1999,8(2):70-77

Abstract– The occurrence of competition between common ( Gobiomorphus cotidianus ) and upland ( G. breviceps ) bullies was tested in summer in artificial channels. Although these species have different life histories, they are morphologically and ecologically similar, and frequently cooccur in New Zealand's fresh waters. Mortality during the test period averaged 11.3±2.4% and 17.7±1.9% for the common bully in triplicate control and experimental channels, respectively; in contrast, upland bully mortality was 2.3±1.9% in the control and zero in the experimental channels. Common bullies showed no significant differences in mean length, weight, condition, and specific growth between the control and experimental tests. For upland bullies, all of the above parameters were significantly less in the controls than the experimentals, an outcome that was indicative of intraspecific competition. Moreover, there was a significant linear trend in the distribution of upland bullies, with their numbers being highest at the upstream end of the channels in both the control and experimental tests. Common bullies showed no such trend, although significantly higher proportions of fish were present towards the central positions in the experimental channels, suggesting there was some displacement of them by upland bullies. It is concluded that interspecific competition is not of major importance between populations of these two eleotrids in small streams, although the abundance and upstream penetration of common bullies may be affected to some extent by interaction with upland bullies.  相似文献   

Recent advance in cardiac ion channel remodeling in diabetes     

LI Jian  LIU Tong  LI Guang-ping 《园艺学报》2012,28(4):751

Occurrence of lethal cardiac arrhythmia, which is associated with prolongation of the QT interval in electrocardiogram(ECG), is related to increased mortality in the patients with diabetes mellitus (DM). Increased QT interval reflects the prolonged cardiac action potential duration (APD). APD abnormality is based on by cardiac ion channel remodeling induced by DM-related pathological changes. As DM is becoming an important risk factor for atrial fibrillation, the most clinically common arrhythmia, this review mainly summarizes the alterations of ion channel currents and relevant protein expression in diabetic ventricular myocytes to explore the underlying mechanisms of arrhythmia, and also discusses some research achievements from investigating the atrial myocytes in DM.  相似文献   

新疆混凝土渠道冻害原因及其防治措施     

孙宏军 《北京农业》2012,(6):270

混凝土衬砌渠具有水利用系数大、耐久性好、强度高、便于养护管理等优点,而它的缺点是在在新疆的气候条件下易遭冻胀破坏,影响了渠道的使用功能,因此在渠道设计、施工及运行管理中要充分重视渠道的冻害。  相似文献   

《中国木本植物种子》     

ZHOU You-lin  SHEN Yue-liang  CHEN Ying-ying  WU Xun-dong  XIA Qiang 《园艺学报》2004,31(1):63-66

AIM: To test whether ischemic preconditioning (IPC) delays ischemia-induced electrical uncoupling by activation of mitochondrial ATP-sensitive potassium channels (mitoK_ATP). METHODS: Adult rat hearts perfused on a Langendorff apparatus were subjected to 40 min ischemia followed by 30 min reperfusion. Changes in coupling were monitored by measuring whole-tissue resistance. RESULTS: IPC delayed the onset of uncoupling campared to ischemic control; Blocking mitoK_ATP channels before the IPC protocol abolished the delay of uncoupling. The specific mitoK_ATP channel opener diazoxide mimicked the protective effect of IPC. The delay induced by diazoxide was reduced by 5-HD, L-type Ca²⁺ channel inhibitor verapamil and a free radical scavenger N-(2-mercaptopropionyl)glycine. CONCLUSIONS: IPC delays the onset of cellular electrical uncoupling induced by acute ischemia, in which activation of the mitoK_ATP channels may be involved.  相似文献   

Effect of Ba²⁺ concentration on L-type Ca²⁺ channel in hypothalamic neurons     

FU Qing-jie  ZOU Fei 《园艺学报》2002,18(5):466-468

AIM:To investigate the effect of Ba²⁺ concentration on L-type of Ca²⁺ channel in hypothalamic neurons.METHODS:The cell acute isolation technique and cell-attached patch-clamp technique were used.RESULTS:The slope conductance of L-type Ca²⁺ channel were 28.6 pS (110 mmol/L) and 19.1 pS (10 mmol/L), and the open probability (NP₀) obviously different with different Ba²⁺ concentration as carrier. CONCLUSION:Ba²⁺ concentration had the obvious effect on the L-type Ca²⁺ channel.  相似文献