Showing papers in "Journal of Molecular and Cellular Cardiology in 1970"

TL;DR: The early cessation of contractile activity in ischemic myocardial cells appears to be the result of a reduction in the rate of regeneration of a small pool of extra-mitochondrial ATP available for muscle contraction and other ATP requiring processes such as ion transport.

TL;DR: Even after a pronounced reduction of the myocardial energy demands following cardioplegia and/or hypothermia, anaerobic glycolytic energy production is insufficient to cover the my cardiac energy demands during ischemia.

TL;DR: It is proposed that the ionic mechanisms associated with the inotropic response which follows increased frequency of contraction (Bowditch Staircase) and glycoside administration are essentially the same.

TL;DR: It is apparent that Z substance is essential for the production of new sarcomeres in the myofibril, and is the source of new contractile units in situations of growth, maintenance and repair in the heart.

TL;DR: Heart failure was correlated with the extent of cellular alterations in the early stages, but poorly in the later ones, while the average sarcomere length never differed from controls.

TL;DR: The diffusion of adenosine from the intracellular to the extracellular space cannot be essential for the coronary dilating action of dipyridamol and, therefore, not for the local metabolic regulation of coronary blood flow.

TL;DR: Oxidative phosphorylation and calcium transport were measured in mitochondria isolated from cardiomyopathic hamster hearts and the magnitude of the changes appear to be related to the severity of failure.

TL;DR: Alterations of the contractile elements were found only in association with myocardial necrosis and were characterized by hyalinization and loss of the striations and appeared to be largely reversible.

TL;DR: Ouabain binding in the presence of ATP, Mg2+, Na+ and K+ was shown to be time-dependent and a direct temporal correlation between ouABain binding and inhibition of specific activity of the enzyme system was demonstrated.

TL;DR: It is suggested that an aberration of intracellular calcium metabolism is characteristic of congestive heart failure associated with the cardiomyopathic process.

TL;DR: It is proposed that the external lamina acts as a selective barrier between the intra- and extracellular environment in cells in which the myofibrils are either centrally located or evenly distributed within the cell.

TL;DR: It is shown that cardiac SR has the Ca capacity and uptake rate required for physiologic relaxation and had no rapid Ca uptake, and represents the initial isolation of myocardial SL, localizes the Na-K ATPase to this organelle and provides a subcellular site for control of Na movements and a site of action for digitalis.

TL;DR: Observations on the stimulating influence of dibutyryl cyclic AMP upon the automacity of the cultured heart cells suggest, in conjunction with other evidence reported in the literature, that cyclicAMP is an intermediate in the pathway of the positive chronotropic action of adrenaline on cardiac pacemaker cells.

TL;DR: Histological changes as well as biochemical abnormalities were present in the hearts of hamsters 5 weeks of age, with exception of a prolonged t-PH period of the myopathic hearts of group I, tension development and contractility were normal up to 3 months of age.

TL;DR: A reduced content of contractile proteins and a reduced ATPase activity may be in a causal relation to the impaired myocardial contractility in the failing heart.

TL;DR: Arterial-coronary sinus differences of triglyceride concentration were determined in 11 healthy, resting fasting subjects by using an infusion of albumin-bound tritiated palmitate to produce endogenous labelling of plasma triglycerides and also by using a precise chemical method of triglycerides estimation in which glyceride glycerol is measured.

TL;DR: Some degree of increase in lactic dehydrogenase activity was observed in high altitude guinea pigs but the differences between high altitude and low altitude rabbits and dogs were not statistically significant.

TL;DR: A method for cultivating intact foetal mouse hearts in vitro has been developed and the hearts survive and beat rhythmically and spontaneously for 3 weeks or more under appropriate cultural conditions.

TL;DR: A method is described which allows continuous measurements of oxygen uptake, decarboxylation of 14C-substrates and mechanical activity of isolated guinea-pig atria over 18 h in a recirculating system.

TL;DR: The data do indicate, however, that isolated right ventricular failure leads not only to a decreased capacity ofright ventricular adenyl cyclase to respond to glucagon stimulation, but also to a similar impairment of adenol cyclase derived from the unstressed left ventricle.

TL;DR: Sarcolemma, mitochondria, and sarcoplasmic reticulum from canine ventricles were prepared and characterized, and the composition of PL was characteristic: in PE and PS, stearic and arachidonic acids were predominant; in PC, oleic acid was noted; in CL, linoleic acid comprised about 85% of the non-polar moieties.

TL;DR: Conditions are described which favour incorporation of leucine and valine into the protein of isolated rat heart mitochondria which can be preserved at liquid nitrogen temperature, provided that dimethylsulphoxide is present during freezing.

TL;DR: The results indicate a marked hypertrophy is evident 20 to 30 days after surgery with the eventual development of congestive f&lure.

TL;DR: The modification of the myocardial ultrastructure following ischaemic arrest has been studied by examining biopsy samples obtained from a group of seven patients during open heart surgical procedures, interpreted as signs of vacuolar degeneration and interstitial oedema.

TL;DR: The kinetics of calcium exchange were studied in the perfused frog ventricle and compared to the previously defined kinetic analysis of calcium obtained in the dog papillary muscle, which found a similar kinetically-defined component but was representative of some 7 times as much calcium.

TL;DR: Lipid analyses have been made on microsomal and mitochondrial fractions of homogenates of biopsy specimens taken from human ventricles during cardiac surgery and ventricular phospholipid was higher than that in atrial subcellular fractions, the difference being mainly attributable to the higher ventricular content of phosphatidyl choline.