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Recent advances in studies on cardiac structure and metabolism最新文献

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Effects of hypoxia and digitalis glycosides on myocardial stiffness. 缺氧和洋地黄苷对心肌僵硬的影响。
Recent advances in studies on cardiac structure and metabolism Pub Date : 1976-05-26
K Taubert, J T Willerson, W Shapiro, G H Templeton
{"title":"Effects of hypoxia and digitalis glycosides on myocardial stiffness.","authors":"K Taubert,&nbsp;J T Willerson,&nbsp;W Shapiro,&nbsp;G H Templeton","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>The influences of hypoxia and of the interactions of hypoxia with digoxin and ouabain on myocardial stiffness were studied at two extracellular calcium concentrations (2.5 mM and 4.0 mM) in isolated, isometrically contracting cat papillary muscles. Stiffness (delta T/delta L), defined as a change in tension (delta T) in response to an imposed length change (delta L), was measured during contraction and during rest by use of a sinusoidal forcing function. Neither digoxin, ouabain, nor increased extracellular calcium altered contraction or resting stiffness in the well-oxygenated environment. Resting stiffness was increased at the end of hypoxia only in the presence of digoxin in both 2.5 mM and 4.0 mM Ca. Contraction stiffness was increased in 2.5 mM Ca by hypoxia alone and by hypoxia in the presence of digoxin or ouabain, but was not increased in experiments carried out in 4.0 mM Ca. Thus it appears that hypoxia per se increases contraction stiffness, but increasing extracellular calcium from 2.5 mM to 4.0 mM prevents the increase elicited by hypoxia; resting stiffness, however, is increased by hypoxia only in the presence of digoxin, and this occurs in both 2.5 mM and 4.0 mM Ca.</p>","PeriodicalId":21025,"journal":{"name":"Recent advances in studies on cardiac structure and metabolism","volume":"11 ","pages":"407-11"},"PeriodicalIF":0.0,"publicationDate":"1976-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12212792","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
Interaction of lanthanides with muscle microsomes. 镧系元素与肌肉微粒体的相互作用。
Recent advances in studies on cardiac structure and metabolism Pub Date : 1976-05-26
N Krasnow
{"title":"Interaction of lanthanides with muscle microsomes.","authors":"N Krasnow","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>The interaction of gadolinium, a lanthanide with calcium-blocking action, with isolated muscle microsomes has been studied. Two classes of binding sites were present, 80 and in excess of 300 nmol/mg in number, respectively. Divalent cation, including Ca, Zn, and Cd, blocked the higher affinity site. Antibiotic ionophores X537A and A23187 enhanced binding, with positive cooperativity. ATP enhanced binding at low concentration (10-20 muM) of nucleotide, and without ATP-hydrolysis. The data suggest a dissociation in the intact membrane between the binding and ATP-hydrolytic portion of the transport site.</p>","PeriodicalId":21025,"journal":{"name":"Recent advances in studies on cardiac structure and metabolism","volume":"11 ","pages":"297-304"},"PeriodicalIF":0.0,"publicationDate":"1976-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12212962","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 new spectroscopic approach to cardiac energy metabolism. 心脏能量代谢的新光谱方法。
Recent advances in studies on cardiac structure and metabolism Pub Date : 1976-05-26
M Tamura, N Oshino, B Chance
{"title":"A new spectroscopic approach to cardiac energy metabolism.","authors":"M Tamura,&nbsp;N Oshino,&nbsp;B Chance","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>The optical characteristics of the hemoglobin-free perfused rat heart have been examined in detail. For dual-wavelength spectrophotometry, absorption pairs at 605-620 nm and 587-620 nm are found to be suited for the investigation of the oxidation-reduction changes of cytochrome aa3 and oxygenation-deoxygenation of myoglobin in cardiac tissue. Techniques by which the absorption changes of myoglobin and cytochrome aa3 can be measured during one cycle of contraction-relaxation are presented. The results demonstrate that, in the aerobic state, myoglobin is more oxygenated during the systolic and diastolic periods and deoxygenated in the resting period, whereas cytochrome aa3 is more reduced in the systole and diastole and oxidized in the resting period.</p>","PeriodicalId":21025,"journal":{"name":"Recent advances in studies on cardiac structure and metabolism","volume":"11 ","pages":"307-12"},"PeriodicalIF":0.0,"publicationDate":"1976-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12212964","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
Evaluation of perfusion conditions in cardiopulmonary bypass. 体外循环灌注条件的评价。
Recent advances in studies on cardiac structure and metabolism Pub Date : 1976-05-26
S Canković-Darracott, M V Braimbridge, J Chayen, L Bitensky
{"title":"Evaluation of perfusion conditions in cardiopulmonary bypass.","authors":"S Canković-Darracott,&nbsp;M V Braimbridge,&nbsp;J Chayen,&nbsp;L Bitensky","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Fresh sections of left ventricular drill biopsies, taken at the beginning and end of cardiopulmonary bypass in 164 patients undergoing aortic valve replacement, have been analyzed for myocardial function. This has been assessed by changes in biochemical function, measured by semi-quantitative histochemical methods, and by changes in birefringence, measured quantitatively by polarization microscopy. It has been shown that continuous perfusion at 32 degrees C with the heart beating provided better preservation than did the other three perfusion procedures, in all of which the heart was fibrillating. More recently, in a small number of cases, cardioplegic arrest has been found to given even better preservation.</p>","PeriodicalId":21025,"journal":{"name":"Recent advances in studies on cardiac structure and metabolism","volume":"12 ","pages":"593-6"},"PeriodicalIF":0.0,"publicationDate":"1976-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12212975","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
Palmitate oxidation by beating heart cells in culture. 培养中心脏细胞跳动时棕榈酸酯氧化。
Recent advances in studies on cardiac structure and metabolism Pub Date : 1976-05-26
A Pinson, C Frelin, P Padieu
{"title":"Palmitate oxidation by beating heart cells in culture.","authors":"A Pinson,&nbsp;C Frelin,&nbsp;P Padieu","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Palmitic acid oxidation has been studied in cultures of beating heart cells. The data reported suggest: 1. The main source of fatty acids for oxidation in cell cultures is provided by lypolysis of preexisting intracellular fatty acids. Most fatty acids that have just entered the cell are not oxidized immediately. Thus, aged heart cells in culture seem to retain their ability to utilize fatty acids as their main energy source. 2. In cultured heart cells, the amount of CO2 obtained from the carboxyl group was much higher than that obtained from the methyl group. On the other hand, beta-hydroxybutrate has been shown to be formed mainly from the methyl group. This may indicate that beta-oxidation terminates at the beta-hydroxybutyrate stage because of premature dissociation of this last intermediate from the enzyme complex.</p>","PeriodicalId":21025,"journal":{"name":"Recent advances in studies on cardiac structure and metabolism","volume":"12 ","pages":"667-75"},"PeriodicalIF":0.0,"publicationDate":"1976-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12212977","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
Autophagy in cardiac myocytes. 心肌细胞的自噬。
Recent advances in studies on cardiac structure and metabolism Pub Date : 1976-05-26
H D Sybers, J Ingwall, M DeLuca
{"title":"Autophagy in cardiac myocytes.","authors":"H D Sybers,&nbsp;J Ingwall,&nbsp;M DeLuca","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>The fetal mouse heart (FMH) in organ culture continues to beat for a period of weeks, but degenerative changes occur. Electron microscopy revealed formation of autophagic vacuoles containing damaged organelles in some cells after the first day, indicating focal cytoplasmic injury. This process was accelerated by transient deprivation of oxygen and glucose followed by resupply of oxygen and glucose. FMHs were maintained for up to four hours in glucose-free media in an atmosphere of 95% N/5% CO2 followed by resupply of O2 and glucose. Twenty-four hours later, many cells recovered without residual injury. Many others revealed autophagic vacuoles ranging from those in which organelles were readily identified to those characteristic of residual bodies. It appears that focal injury stimulates the endoplasmic reticulum to enclose the damaged components, permitting localized lysosomal digestion without causing injury to the entire cell. Autophagy has not been emphasized as an important mechanism in transient ischemia in adult myocytes, but it may play a role in repair of sublethal injury. The FMH organ culture provides an excellent model for studying the sequential autophagic changes in a system in which these events can be accelerated.</p>","PeriodicalId":21025,"journal":{"name":"Recent advances in studies on cardiac structure and metabolism","volume":"12 ","pages":"453-63"},"PeriodicalIF":0.0,"publicationDate":"1976-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12213119","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
Preservation of myocardial membrane integrity in the early phase of acute myocardial ischemia. 急性心肌缺血早期心肌膜完整性的保存。
Recent advances in studies on cardiac structure and metabolism Pub Date : 1976-05-26
M Okuda, A M Lefer
{"title":"Preservation of myocardial membrane integrity in the early phase of acute myocardial ischemia.","authors":"M Okuda,&nbsp;A M Lefer","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Myocardial uptake of dexamethasone (Dex) or methylprednisolone (MP) was studied using tritiated tracers in isolated perfused cat hearts during acute myocardial ischemia. Considerable amounts of Dex and MP were incorported into the plasma membranes in control, border-zone, and ischemic myocardium. Lesser amounts were bound to the remaining subcellular organelles. A gradient of the glucocorticoid uptake was observed decreasing from control myocardium to ischemic myocardium in all subcellular fractions. By the first hour of ischemia, the myocardial plasma membranes underwent marked depletion of activity of 5'-nucleotidase, a plasma membrane marker enzyme, indicating early loss of plasma membrane integrity in acute myocardial ischemia. The incorporation of Dex or MP into the plasma membranes resulted in a significant decrease in loww of 5'-nucleotidase activity of the plasma membranes in the border-zone and ischemic myocardium. The data provide direct evidence 1) to support a membrane stabilizing action of glucocorticoids, and 2) to focus on the plasma membranes as a potentially important site of protection during the early phase of acute myocardial ischemia.</p>","PeriodicalId":21025,"journal":{"name":"Recent advances in studies on cardiac structure and metabolism","volume":"12 ","pages":"507-11"},"PeriodicalIF":0.0,"publicationDate":"1976-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12213124","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
Coronary circulation, myocardial metabolism and hemodynamics of pacing-induced angina. 起搏性心绞痛的冠状动脉循环、心肌代谢和血流动力学。
Recent advances in studies on cardiac structure and metabolism Pub Date : 1976-05-26
K Tamura, N Higuma, S Bannai, R Aoyagi, T Izumi, M Matsuoka, S Eguchi
{"title":"Coronary circulation, myocardial metabolism and hemodynamics of pacing-induced angina.","authors":"K Tamura,&nbsp;N Higuma,&nbsp;S Bannai,&nbsp;R Aoyagi,&nbsp;T Izumi,&nbsp;M Matsuoka,&nbsp;S Eguchi","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>The following changes were noted during pacing-induced angina: The coronary sinus blood flow was less than it was during the control period and less than that in the myocardial ischemic group without induced angina. While myocardial oxygen consumption did not increase, myocardial metabolism became anaerobic. The possibility of myocardial dysfunction also was noted.</p>","PeriodicalId":21025,"journal":{"name":"Recent advances in studies on cardiac structure and metabolism","volume":"12 ","pages":"265-70"},"PeriodicalIF":0.0,"publicationDate":"1976-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12213372","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
Effect of graded coronary stenosis on regional myocardial blood flow and left ventricular function. 分级冠状动脉狭窄对局部心肌血流及左心室功能的影响。
Recent advances in studies on cardiac structure and metabolism Pub Date : 1976-05-26
M Nakamura, H Matsuguchi, A Mitsutake, A Takeshita, Y Kikuchi, M Mori, Y Koiwaya, Y Nose, A Kuroiwa
{"title":"Effect of graded coronary stenosis on regional myocardial blood flow and left ventricular function.","authors":"M Nakamura,&nbsp;H Matsuguchi,&nbsp;A Mitsutake,&nbsp;A Takeshita,&nbsp;Y Kikuchi,&nbsp;M Mori,&nbsp;Y Koiwaya,&nbsp;Y Nose,&nbsp;A Kuroiwa","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Dogs with 70% stenosis of the left circumflex coronary artery showed a reduction of myocardial blood flow with a minimal impairment of left ventricular wall motion. Eighty to ninety percent stenosis produced a marked reduction of flow and wall motion, and ST elevation close to 100% occlusion, but delayed antegrade run-off was found. The effectiveness of collaterals to protect against left ventricular dysfunction was supported.</p>","PeriodicalId":21025,"journal":{"name":"Recent advances in studies on cardiac structure and metabolism","volume":"12 ","pages":"213-7"},"PeriodicalIF":0.0,"publicationDate":"1976-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12217028","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
Regulatory mechanism in arterial smooth muscle contraction. 动脉平滑肌收缩的调节机制。
Recent advances in studies on cardiac structure and metabolism Pub Date : 1976-05-26
T Koizumi, Y Ito, S Ebashi
{"title":"Regulatory mechanism in arterial smooth muscle contraction.","authors":"T Koizumi,&nbsp;Y Ito,&nbsp;S Ebashi","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>The regulatory mechanism in the aortic actomyosin system was studied. Superprecipitation of desensitized aortic myosin B was not exhibited even in the presence of Ca2+, but was observable only in the presence of native tropomyosin and Ca2+. Reconstituted actomyosin composed of pure aortic myosin and pure skeletal actin did not show superprecipitation. Addition of aortic native tropomyosin and Ca2+ caused a marked superprecipitation. The ATPase of reconstituted actomyosin was enhanced three- or fourfold by aortic native tropomyosin and Ca2+. The extent of superprecipitation of aortic myosin B did not show a biphasic type of response to Mg-ATP concentration. Thus, aortic native tropomyosin induces a real activation of the myosin, actin, and ATP system in the presence of Ca2+, in contrast with the case of skeletal native tropomyosin, which induces the depression of skeletal myosin-actin-ATP interaction in the absence of Ca2+.</p>","PeriodicalId":21025,"journal":{"name":"Recent advances in studies on cardiac structure and metabolism","volume":"11 ","pages":"185-91"},"PeriodicalIF":0.0,"publicationDate":"1976-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"11364982","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
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