Changes in [Ca2+]i Induced by Rapid Cooling of Single Skeletal Muscle Fibres Treated with Low Concentration of Caffeine
In single skeletal muscle fibres treated with low concentration of caffeine, lowering the bathing solution temperature from 18°C to below 7°C increased [Ca2+]i in three phases depending on caffeine concentration and temperature. Tension could be fully developed (rapid cooling contracture, RCC) by the second phase of the released Ca2+. The second and third phases were inhibited by low concentrations of procaine, and the first phase was blocked by a higher one. RCC was observed even in Ca2+-free solution. The mechanism of [Ca2+]i changes and RCC during cooling was discussed.
KeywordsCaffeine Concentration Single Muscle Fibre Japan Acad Reach Maximum Level Induce Calcium Release
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