Advances in myocardiology最新文献_第8页

Phosphorus two-dimensional NMR spectroscopy of perfused rat hearts. 灌注大鼠心脏磷二维核磁共振波谱。

Advances in myocardiology Pub Date : 1985-01-01 DOI: 10.1007/978-1-4757-1287-2_2

P B Garlick, C J Turner

引用次数: 1

Intercellular junctions and the cardiac intercalated disk. 细胞间连接和心间盘。

Advances in myocardiology Pub Date : 1985-01-01 DOI: 10.1007/978-1-4757-1287-2_18

N J Severs

引用次数: 28

Potassium balance and ouabain binding sites in intact porcine hearts during isoproterenol infusion. 异丙肾上腺素输注过程中完整猪心脏的钾平衡和豆碱结合位点。

Advances in myocardiology Pub Date : 1985-01-01

O M Sejersted, F R Andersen, A Ilebekk

{"title":"Potassium balance and ouabain binding sites in intact porcine hearts during isoproterenol infusion.","authors":"O M Sejersted, F R Andersen, A Ilebekk","doi":"","DOIUrl":"","url":null,"abstract":"A pacing-induced tachycardia causes a net loss of K+ from the myocardium whereas adrenergic stimulation at constant heart rate will cause a net K+ accumulation. In the intact heart, isoproterenol (ISO) will, as expected, exert both effects, but the net result with regard to K+ balance is unknown. In the experiments on intact porcine hearts presented herein, a shunt from the coronary sinus to the right atrium allowed continuous monitoring of the myocardial K+ balance. ISO caused heart rate, dP/dt, and peak aortic flow to increase to a new steady state in less than 10 sec. There was an initial K+ loss lasting 1 min followed by a 10- to 15-times larger net uptake subsiding after 7 min. Overall, tissue K+ increased by 140.5 +/- 60.0 mumole/100 g, corresponding roughly to a 3 mM increase in intracellular concentration during ISO infusion. Ouabain binding sites determined in intact biopsies from the left ventricle remained unchanged. Thus, ISO has a biphasic effect on myocardial K+ balance, eventually causing a net increase of tissue K+ content probably unrelated to the inotropic effects. Direct stimulation of the Na+, K+-ATPase without changing the number of enzymes is possible.","PeriodicalId":77831,"journal":{"name":"Advances in myocardiology","volume":"6 ","pages":"83-95"},"PeriodicalIF":0.0,"publicationDate":"1985-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"15103910","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Verapamil and nifedipine limit infarct size in the dog. 维拉帕米和硝苯地平限制狗的梗死面积。

Advances in myocardiology Pub Date : 1985-01-01

J M Downey, D J Hearse, S Yoshida, M P Maxwell, D M Yellon

{"title":"Verapamil and nifedipine limit infarct size in the dog.","authors":"J M Downey, D J Hearse, S Yoshida, M P Maxwell, D M Yellon","doi":"","DOIUrl":"","url":null,"abstract":"We studied the ability of two calcium antagonists, nifedipine and verapamil, to limit infarct size in the closed-chest, coronary-embolized dog. Immediately after embolization, 141Ce-labeled microspheres were administered into the left ventricle. Myocardium not receiving microspheres was considered to be the region at risk. The nifedipine group received 16 micrograms/kg, i.v., over 8 min as a loading dose, followed by continuous infusion (0.04 mg/kg per 24 hr) within 10 min after embolization. The verapamil group received a 0.2 mg/kg bolus over 2 min, followed by a continuous infusion of 8 mg/kg per 24 hr. Again, the drug was started within 10 min of embolization. The control groups received an equal volume of saline. At 24 hr after embolization, the dogs were sacrificed, the hearts were sectioned into 3-mm slices, and the slices were stained with tetrazolium to reveal the infarct. The region at risk was determined by autoradiography of the microspheres in the heart slices. Infarct and risk-zone volume were determined by planimetric methods. Infarct size was normalized by expressing it as a percentage of the region at risk. Nifedipine significantly reduced this percentage when compared to matched controls (38.7 +/- 4.7 vs. 79.5 +/- 4.3%, p less than 0.001). Similarly, verapamil also reduced infarct size (18.0 +/- 4.4 vs. 62.0 +/- 7.4%, p less than 0.001). We conclude that both these drugs appear to offer protection in the presence of permanent coronary occlusion.","PeriodicalId":77831,"journal":{"name":"Advances in myocardiology","volume":"6 ","pages":"529-43"},"PeriodicalIF":0.0,"publicationDate":"1985-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"15103993","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A model for cardiac ischemia. Cardiac cells transplanted into the renal capsular space of the rat and their electrophysiological properties. 心脏缺血模型。大鼠肾包膜内移植心肌细胞及其电生理特性。

Advances in myocardiology Pub Date : 1985-01-01

Y Nishizono, K Nishi

{"title":"A model for cardiac ischemia. Cardiac cells transplanted into the renal capsular space of the rat and their electrophysiological properties.","authors":"Y Nishizono, K Nishi","doi":"","DOIUrl":"","url":null,"abstract":"We have developed a new model for electrophysiological studies on ischemic myocardium in situ. Pieces of ventricular tissue (1 X 1 mm) excised from the neonatal rat heart were transplanted into the renal capsular space of the adult rat of the pure strain F 344-NSlc. Electrophysiological properties of the transplanted cells during normal circulation and during ischemia induced by ligation of the renal artery were examined in situ 7-10 days later, when the tissues were fully vascularized, by means of conventional microelectrode techniques. Transmembrane potentials varied in individual cells, ranging from -60 to -90 mV. The amplitude, duration, and configuration of spontaneously occurring action potentials recorded from the transplanted cells were similar to those obtained in neonatal and adult rat myocardium. At 2-5 min after ligation of the renal artery, the frequency of the action potentials decreased markedly and their duration was transiently prolonged and then shortened. During the initial stage of ischemia (5-15 min), most of the cells were markedly depolarized and spontaneous activity ceased. Within 20-30 min, after the ligation, the cells did not respond to electrical stimulation. Reperfusion of the tissue by releasing the ligation restored the electrical activity of the cells within 15 min when a certain limited time of ischemia (30-40 min) was not exceeded.","PeriodicalId":77831,"journal":{"name":"Advances in myocardiology","volume":"6 ","pages":"383-93"},"PeriodicalIF":0.0,"publicationDate":"1985-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"15106646","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Catecholamine-induced necrosis and hypertrophy. Hemodynamic factors. 儿茶酚胺引起的坏死和肥厚。血流动力学因素。

Advances in myocardiology Pub Date : 1985-01-01

K M Middleton, A H Henderson, M J Lewis

引用次数: 0

Characterization of calmodulin-dependent and cyclic-AMP-dependent protein kinase stimulation of cardiac sarcoplasmic reticulum calcium transport. 钙调素依赖性和环amp依赖性蛋白激酶刺激心肌肌浆网钙转运的表征。

Advances in myocardiology Pub Date : 1985-01-01 DOI: 10.1016/0022-2828(83)91033-7

S. Katz, B. Richter, B. Eibschutz

引用次数: 3

The oxygen free radical system and myocardial dysfunction. 氧自由基系统与心肌功能障碍。

Advances in myocardiology Pub Date : 1985-01-01 DOI: 10.1007/978-1-4757-1287-2_13

M L Hess, N H Manson

引用次数: 8

Morphometric analysis of calcium-tolerant myocytes isolated from the adult rat heart. 从成年大鼠心脏分离的钙耐受心肌细胞的形态计量学分析。

Advances in myocardiology Pub Date : 1985-01-01

A M Slade, N J Severs, T Powell, V W Twist, G E Jones

{"title":"Morphometric analysis of calcium-tolerant myocytes isolated from the adult rat heart.","authors":"A M Slade, N J Severs, T Powell, V W Twist, G E Jones","doi":"","DOIUrl":"","url":null,"abstract":"The ultrastructure of calcium-tolerant isolated myocytes has been compared with that of intact heart myocytes using morphometric techniques. Isolated myocytes were prepared by the method of Powell et al. [1] from four adult rat hearts, and multiple left ventricular tissue samples were obtained from a further four rat hearts after fixation by Langendorff perfusion. The subcellular-component volumes of myofibrils, mitochondria, nuclei, transverse tubules, sarcoplasmic reticulum, lipid droplets, and cytoplasmic space have been estimated using a point-counting method on thin sections of intact myocardium and isolated myocytes. No significant differences between the two sample types were found. With the use of freeze-fracture, the numerical density and distribution of sarcolemmal intramembrane particles were analyzed by the method of Jones et al. [2]. The intramembrane particle density of isolated myocyte E-faces was very similar to that of myocytes of intact myocardium. However, isolated myocytes showed a slight reduction in P-face intramembrane particle density (less than 10%), although intramembrane particle distribution remained unaltered on both fracture faces. Our findings show that the ultrastructural features of the isolated myocytes closely resemble those of their counterparts in the intact myocardium.","PeriodicalId":77831,"journal":{"name":"Advances in myocardiology","volume":"6 ","pages":"3-12"},"PeriodicalIF":0.0,"publicationDate":"1985-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"14120320","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Ultrastructure of the sarcoplasmic reticulum in the ischemic myocardium. 缺血心肌肌浆网的超微结构。

Advances in myocardiology Pub Date : 1985-01-01

K Akiyama, T Katagiri, E Iijima, N Konno, T Yanagishita, F Tanno, H Kanaya, S Sekita, Y Takeyama, H Niitani

{"title":"Ultrastructure of the sarcoplasmic reticulum in the ischemic myocardium.","authors":"K Akiyama, T Katagiri, E Iijima, N Konno, T Yanagishita, F Tanno, H Kanaya, S Sekita, Y Takeyama, H Niitani","doi":"","DOIUrl":"","url":null,"abstract":"Fine structural changes in the sarcoplasmic reticulum (SR) in myocardial ischemia, induced by occlusion of the anterior descending branch of the left coronary artery in the canine heart, were studied by the freeze-fracture technique in situ and in vitro and compared to the alterations in Ca2+-stimulated ATPase activity and sodium dodecyl sulfate gel electrophoresis of the isolated SR. Both SR in situ and the isolated SR exhibited the typical intramembranous particles of 70-90 A in freeze-fracture replicas, and the numbers of particles were more numerous in the concave face (PF) than in the convex face (EF). The numbers of particles in the PF were 2748/micron 2 on the average. In ischemia for 1-2 hr, a significant decrease in the numbers of the particles was found in SR in situ, and corresponding changes were noted in the isolated SR. Decreases in Ca2+-stimulated ATPase activity and in the major protein band of ATPase were recognized simultaneously. The close correlation of the changing patterns between the reduction in Ca2+-ATPase and that in the intramembranous particle density during ischemia supports the suggestion that a large part of the intramembranous particles represents ATPase protein itself. The decrease in the particles of SR membrane indicates the degradation of ATPase in the process of ischemic myocardial necrosis.","PeriodicalId":77831,"journal":{"name":"Advances in myocardiology","volume":"6 ","pages":"451-9"},"PeriodicalIF":0.0,"publicationDate":"1985-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"14120321","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0