In order to find drugs with suppressive effects against sudden cardiac cell dea ... UOl of the response to K t was less marked than that by diltiazem. Its inhibition of the response to NE was greater than that by diltiazem or KT362. K201 demonstrated an inhibitory effect on binding of cardiac annexin V with actin dependent on calcium concentration, but diltiazem and KT362 did not demonstrate any action to inhibit this reaction. These results indicate that K201 was a more effective cardioprotectant than propranolol, verapamil, and diltiazem in the experimental myofibrillar overcontraction model. K201 has intracellular Ca2+ blocking action in addition to weak a-.l adrenergic blocking activity and Ca" blocking activity. o 1994 \ViIey-Liss, Inc.
A newly devised procedure of time series analysis, which is a linearized version of the nonlinear least squares method combined with the maximum entropy spectral analysis method, was proposed and applied to the annual sunspot number data from 1700 to 1991. Multiple periodicities of the temporal variation were elucidated in detail. The solar cycle of a 11.04-year period accompanied with the solar cycle multiplets, the periods of 50.41 years, the so-called “Yoshimura cycle”, and 107.11 years corresponding to the cycle of century-scale minima, for example, were clearly observed. The optimum least squares fitting curve for the data was extended over the past two millennia and the next millennium. The past grand minima such as the Maunder minimum were confirmed in the past extrapolation curve, and the next centennial minimum was predicted to occur between 2000 and 2030.
Objectives: The drug K201 (JTV-519) increases inotropy and suppresses arrhythmias in failing hearts, but the effects of K201 on normal hearts is unknown. Methods: The effect of K201 on excitation-contraction (E-C) coupling in normal myocardium was studied by using voltage-clamp and intracellular Ca 2+ measurements in intact cells. Sarcoplasmic reticulum (SR) function was assessed using permeabilised cardiomyocytes. Results: Acute application of b1 μmol/L K201 had no significant effect on E-C coupling. K201 at 1 μmol/L
Three-dimensional reconstruction of the human heart was performed to define the structure of the intramyocardial microvasculature. A total of 200 consecutive serial sections of 6 μm each were prepared from the left ventricular tissue of an autopsied human heart with normal coronary arteries. The corresponding arteriole, venule, and all capillaries were reconstructed using three-dimensional software. The capillary network extended right and left along the cardiomyocyte with major and minor axes of about 130 and 120 μm, respectively. The capillary length from an arteriole to an adjacent venule was about 350 μm. Two types of sack-like structures, the precapillary sinus and the capillary sinus, were present in the capillary network, and many capillaries diverged from these sinuses. The cardiomyocytes were covered with reticular capillaries. In contrast, the precapillary and capillary sinuses were surrounded by many cardiomyocytes. The arterial and venous capillaries were positioned alternately, forming a lattice pattern. Intramyocardial microcirculatory units forming a capillary network from an arteriole to adjacent venules on both sides were present. The sizes of myocardial micronecroses corresponded to that of the intramyocardial microcirculatory unit. These results show that the capillary network is an ordered and anatomically regulated structure and that the microcirculatory unit and the precapillary and capillary sinuses may play an important role in maintaining the intramyocardial microcirculation during contraction and relaxation.
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