Tohkin M, Yoshimatsu N, Matsubara T
Shionogi Research Laboratories, Shionogi & Co., Ltd., Osaka, Japan.
Jpn J Pharmacol. 1988 Jan;46(1):61-9. doi: 10.1254/jjp.46.61.
The effects of epinephrine and dinitrophenol (DNP) on Ca2+-fluxes and energy metabolism were compared in isolated rat hepatocytes and perfused rat livers. Epinephrine increased the cytosolic free Ca2+ concentration ([Ca2+]i), with Ca2+ being extruded into the extracellular space. DNP also increased [Ca2+]i, but did not cause Ca2+ extrusion into the extracellular space. The maximal change of [Ca2+]i caused by DNP was much larger than that by epinephrine. In the absence of extracellular Ca2+, the transient increase of [Ca2+]i due to epinephrine declined rapidly, while the DNP-induced increase was not affected. Although increased oxygen consumption was detected after the addition of epinephrine or DNP, tissue ATP contents decreased markedly by DNP, but not by epinephrine, suggesting that the Ca2+ extrusion is energy-dependent. DNP could activate glycogenolysis even after the depletion of the epinephrine-responsive Ca2+ store in isolated perfused liver, indicating that this intracellular Ca2+ store differed from the DNP-responsive store.
在分离的大鼠肝细胞和灌注的大鼠肝脏中比较了肾上腺素和二硝基苯酚（DNP）对钙离子通量和能量代谢的影响。肾上腺素增加了细胞质游离钙离子浓度（[Ca2+]i），同时钙离子被排出到细胞外空间。DNP也增加了[Ca2+]i，但没有导致钙离子排出到细胞外空间。DNP引起的[Ca2+]i的最大变化比肾上腺素引起的大得多。在没有细胞外钙离子的情况下，肾上腺素引起的[Ca2+]i的短暂增加迅速下降，而DNP诱导的增加不受影响。尽管添加肾上腺素或DNP后检测到耗氧量增加，但DNP使组织ATP含量显著降低，而肾上腺素则没有，这表明钙离子排出是能量依赖的。即使在分离的灌注肝脏中肾上腺素反应性钙离子储存耗尽后，DNP仍能激活糖原分解，这表明这种细胞内钙离子储存与DNP反应性储存不同。
