Developmental changes in the effects of pH on contraction and Ca2+ current in rabbit heart
Developmental changes in the effects of pH on contraction and Ca2+ current in rabbit heart
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DOI：
10.1006/jmcc.1996.0059
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发表时间：
1996-03-01
影响因子：
5
通讯作者：
Klitzner, TS
中科院分区：
文献类型：
--
作者：
Chen, FH;Wetzel, GT;Klitzner, TS
质子抑制心肌中的Ca 2+电流和收缩。本研究比较了降低浴槽溶液pH值对新生和成年兔心脏单细胞收缩、动作电位构型和钙电流的影响。我们发现，细胞外的pH值从7.3至6.3的减少细胞收缩幅度降低到84.3%的控制在分离的新生儿心肌细胞。细胞外pH值的可比变化导致成年细胞中细胞收缩降低至对照的56.2%。同样，与成年动物的乳头肌相比，完整的新生乳头肌的张力产生对外部pH降低的敏感性较低。此外，酸中毒引起的新生细胞中Ca 2+电流的抑制比成年细胞中的抑制更不明显（85 +/-4%v62 +/-4%，pH = 6.3，P
Protons inhibit Ca2+ current and contraction in heart muscle. The present study compares the effects of lowering the pH of the bath solution on single-cell contraction, action potential configuration and Ca2+ currents between neonatal and adult rabbit hearts. We found that a reduction of extracellular pH from 7.3 to 6.3 decreased cell contraction amplitude to 84.3% of control in isolated neonatal myocytes. A comparable change in extracellular pH resulted in a decrease in cell contraction to 56.2% of control in adult cells. Similarly, tension generation in intact neonatal papillary muscles was less sensitive to a decrease in external pH as compared to papillary muscles from adult animals, In addition, acidosis caused a less pronounced inhibition of Ca2+ current in neonatal cells than in adult cells (85 +/- 4% v 62 +/- 4% of control, pH = 6.3, P