Burdyga T V, Magura I S
Department of General Physiology, Kiev State Shevchenko University, USSR.
Gen Physiol Biophys. 1988 Feb;7(1):3-15.
Effects of temperature and Na0+ on the relaxation of guinea-pig ureter smooth muscle were studied. Relaxation of phasic contraction was found to be highly temperature-dependent, practically independent of Na0+ and Ca02+, and resistant to vanadate. The relaxation of the tonic tension of both high-K and low-Na contracture was less temperature-dependent and affected by Na0+. The relaxation of tonic tension produced by introduction of Na0+ was about 3-5 times faster than that produced by Ca-free solution. La3+ ions were found to block the relaxation of the tonic component of the Na+-free contracture initiated by removal of Ca02+. Three systems of regulation of cell calcium are suggested to be operative in the ureter muscle: a fast one which is highly temperature-dependent and responsible for the relaxation of the phasic contraction (probably the sarcoplasmic reticulum), and two slow membrane-linked carriers, one of which is dependent on Na0+ (probably Na-Ca exchange) and another one which is independent of Na0+ and inhibited by La3+ (probably Ca-pump).
研究了温度和钠离子对豚鼠输尿管平滑肌舒张的影响。发现相性收缩的舒张高度依赖于温度，实际上与钠离子和钙离子无关，并且对钒酸盐有抗性。高钾和低钠挛缩的紧张性张力的舒张对温度的依赖性较小，并受钠离子影响。引入钠离子所产生的紧张性张力的舒张比无钙溶液所产生的快约3至5倍。发现镧离子可阻断因去除钙离子而引发的无钠挛缩紧张性成分的舒张。提示在输尿管肌肉中有三种调节细胞钙的系统起作用：一种快速系统，高度依赖于温度，负责相性收缩的舒张（可能是肌浆网），以及两种缓慢的膜联载体，其中一种依赖于钠离子（可能是钠钙交换），另一种不依赖于钠离子且受镧离子抑制（可能是钙泵）。
