EXPRESSION OF SARCOPLASMIC-RETICULUM CA2+ TRANSPORT PROTEINS IN COLD-ACCLIMATING DUCKLINGS
EXPRESSION OF SARCOPLASMIC-RETICULUM CA2+ TRANSPORT PROTEINS IN COLD-ACCLIMATING DUCKLINGS
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DOI：
10.1152/ajpcell.1995.269.4.c955
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发表时间：
1995-10-01
影响因子：
5.5
通讯作者：
MEISSNER, G
中科院分区：
文献类型：
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作者：
DUMONTEIL, E;BARRE, H;MEISSNER, G
通过测定对照组和冷适应组雏鸭肌浆网或内质网Ca ~（2+）-ATP酶（SERCA）、Ca ~（2+）释放通道和钙螯合蛋白表达的时程，研究了冷诱导肌浆网Ca ~（2+）转运蛋白增加与非颤抖性产热（NST）发生的关系。骨骼肌匀浆Ca-45（2+）摄取和[H-3]ryanodine结合的测量表明，需要类似于4 wk的冷适应期才能观察到Ca ~（2+）-ATP酶活性和Ca ~（2+）释放通道含量的显著增加，这与NST的发育密切相关。肌肉匀浆的免疫印迹分析表明，钙螯合蛋白水平没有差异，但揭示了SERCA 2a含量的减少延迟在冷适应鸟和SERCA 1水平增加后4周的冷适应。SERCA 2a的持久性可能与颤抖产热优先发生在慢缩纤维。SERCA 1可能解释了大部分冷诱导的Ca-45（2+）摄取活性的增加，表明在快缩纤维中优先发生Ca 2+依赖的NST。
The relationship between the cold-induced increase in sarcoplasmic reticulum (SR) Ca2+ transport proteins and the development of muscular nonshivering thermogenesis (NST) was investigated by determining the time course of expression of the sarcoplasmic or endoplasmic reticulum Ca2+-ATPase (SERCA), Ca2+ release channel, and calsequestrin in control and cold-acclimating ducklings. Ca-45(2+) uptake and [H-3]ryanodine binding measurements with skeletal muscle homogenates showed that a cold acclimation period of similar to 4 wk was required to observe a substantial increase in Ca2+-ATPase activity and Ca2+ release channel content, which correlates well with NST development. Immunoblot analysis of muscle homogenates showed no differences in calsequestrin levels but revealed that the decrease in SERCA2a content was delayed in cold-acclimating birds and that the SERCA1 level was increased after 4 wk of cold acclimation. The persistence of SERCA2a may be related to shivering thermogenesis occurring preferentially in slow-twitch fibers. SERCA1 may account for most of the cold-induced increase in Ca-45(2+) uptake activity, suggesting the preferential occurrence of a Ca2+-dependent NST in fast-twitch fibers.