Binzoni T, Ferretti G, Barbalat F, Cerretelli P
Department of Physiology, C.M.U., Geneva, Switzerland.
Respir Physiol. 1990 Nov;82(2):137-47. doi: 10.1016/0034-5687(90)90030-3.
The net rate of phosphocreatine hydrolysis [PCr] [symbol; see text], and tissue pH were determined in anaerobic resting frog (Rana Ridibunda Ridibunda) gastrocnemii by 31-P-NMR in the temperature (T) range from 5 to 30 degrees C. Absolute [PCr] [symbol; see text] values from 0.36 to 10.07 mM/h were estimated assuming a resting [PCr] of 26 mM at 20 degrees C. The corresponding Q10 values ranged from 2.1 (30 degrees C) to 17.5 (5 degrees C). Muscle pH was found to be T-dependent with a 10 degrees C drop in T resulting in an increase of 0.1 pH units. At any given T, pH was found to be constant over a period of at least one hour (30 degrees C) from the onset of anaerobiosis. Based on simultaneous [PCr] [symbol; see text] and pH estimates, the contribution of anaerobic glycolysis ([ATPLA]) to the overall rate of ATP resynthesis ([ATPTot]) was estimated assuming a approximately P/La ratio of 1.2. [ATPTot] was then calculated for each investigated T value as the sum of [PCr] and [ATPLa]. [ATPTot] was found to vary between 5 and 30 degrees C from 0.79 mM/h to 22.15 mM/h. The present study, besides proposing a methodology for the assessment of high energy phosphates hydrolysis by 31P-NMR spectroscopy at changing T, provides a comprehensive analysis of the T-dependence of anaerobic metabolism of the resting anaerobic frog gastrocnemius which may be extrapolated to other tissues.
在5至30摄氏度的温度（T）范围内，通过31-P-NMR测定了处于静息状态的厌氧青蛙（泽蛙指名亚种）腓肠肌中磷酸肌酸水解的净速率[PCr]（符号；见正文）和组织pH值。假设在20摄氏度时静息[PCr]为26 mM，估计绝对[PCr]值在0.36至10.07 mM/h之间。相应的Q10值范围为2.1（30摄氏度）至17.5（5摄氏度）。发现肌肉pH值依赖于温度，温度每下降10摄氏度，pH值增加0.1个单位。在任何给定温度下，从厌氧开始至少一小时（30摄氏度）内pH值保持恒定。基于同时测定的[PCr]（符号；见正文）和pH值估计，假设P/La比值约为1.2，估计厌氧糖酵解（[ATPLA]）对ATP再合成总速率（[ATPTot]）的贡献。然后将每个研究温度值下的[PCr]和[ATPLa]相加计算出[ATPTot]。发现[ATPTot]在5至30摄氏度之间从0.79 mM/h变化到22.15 mM/h。本研究除了提出一种在温度变化时通过31P-NMR光谱评估高能磷酸盐水解的方法外，还对静息厌氧青蛙腓肠肌厌氧代谢的温度依赖性进行了全面分析，该分析可能适用于其他组织。
