Calcium depletion in frog muscle tubules: the decline of calcium current under maintained depolarization.
نویسندگان
چکیده
منابع مشابه
Microinjection of strong calcium buffers suppresses the peak of calcium release during depolarization in frog skeletal muscle fibers
The effects of high intracellular concentrations of various calcium buffers on the myoplasmic calcium transient and on the rate of release of calcium (Rrel) from the sarcoplasmic reticulum (SR) were studied in voltage-clamped frog skeletal muscle fibers. The changes in intracellular calcium concentration (delta[Ca2+]) for 200-ms pulses to 0-20 mV were recorded before and after the injection of ...
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نتایج این مطالعه نشان می دهد که مقدار کلسیم (یونیزه و تام)، منیزیم و فسفر به طور معنی داری تغییر پیدا کرد به جزء مقدار کلسیم تام و منیزیم در روش داخل عضلانی که تغییر معنی داری نداشته است. بر اساس نتایج این مطالعه می توان نتیجه گیری کرد که اکسی تتراساکلین بر روی مقادیر سرمی کلسیم و منیزیم تأثیر می گذارد باید مقدار این کاتیون ها در بیماران، در هنگامی که اکسی تتراسایکلین استفاده می شود مورد توجه ق...
15 صفحه اولEffects of Partial Sarcoplasmic Reticulum Calcium Depletion on Calcium Release in Frog Cut Muscle Fibers Equilibrated with 20 mM EGTA
Resting sarcoplasmic reticulum (SR) Ca content ([CaSR]R) was varied in cut fibers equilibrated with an internal solution that contained 20 mM EGTA and 0-1.76 mM Ca. SR Ca release and [CaSR]R were measured with the EGTA-phenol red method (. J. Gen. Physiol. 106:259-336). After an action potential, the fractional amount of Ca released from the SR increased from 0.17 to 0.50 when [CaSR]R was reduc...
متن کاملLow myoplasmic Mg2+ potentiates calcium release during depolarization of frog skeletal muscle fibers
The role of intracellular free magnesium concentration ([Mg2+]) in modulating calcium release from the sarcoplasmic reticulum (SR) was studied in voltage-clamped frog cut skeletal muscle fibers equilibrated with cut end solutions containing two calcium indicators, fura-2 and antipyrylazo III (AP III), and various concentrations of free Mg2+ (25 microM-1 mM) obtained by adding appropriate total ...
متن کاملEffect of sarcoplasmic reticulum calcium depletion on intramembranous charge movement in frog cut muscle fibers
Cut muscle fibers from Rana temporaria (sarcomere length, 3.3-3.5 microns; temperature, 13-16 degrees C) were mounted in a double Vaseline-gap chamber and equilibrated for at least an hour with an internal solution that contained 20 mM EGTA and phenol red and an external solution that contained predominantly TEA-gluconate; both solutions were nominally Ca-free. The increase in total myoplasmic ...
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ژورنال
عنوان ژورنال: The Journal of Physiology
سال: 1981
ISSN: 0022-3751
DOI: 10.1113/jphysiol.1981.sp013623