LOCALIZATION OF CALCIUM CHANNELS IN PARAMECIUM-CAUDATUM
LOCALIZATION OF CALCIUM CHANNELS IN PARAMECIUM-CAUDATUM
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DOI：
10.1113/jphysiol.1977.sp011993
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发表时间：
1977-01-01
影响因子：
5.5
通讯作者：
DUNLAP, K
中科院分区：
文献类型：
--
作者：
DUNLAP, K
在用水合氯醛去除纤毛后和纤毛再生过程中，记录尾端纤毛的电记录，以研究包裹纤毛轴丝的那部分表面膜的电特性。去除体细胞纤毛(膜表面积减少50%)，几乎完全消除了再生的钙反应，全有或全无Ba2+尖峰，并延迟了整流。由于膜表面积减少了50%，输入电阻增加了2倍。电学性质保持不变，尽管长时间暴露在水合氯醛中，直到纤毛被机械移除。随着纤毛的再生，钙反应的恢复，当纤毛恢复到原来的长度时，完全的兴奋性又回来了。电压敏感的钙通道位于纤毛周围的表面膜上。纤毛草履虫纤毛分离前后膜常数的测定和线缆常数的估算表明，纤毛草履虫纤毛沿其长度和主要细胞室可能是完全等电势的。
Electrical recordings from P. caudatum were made after removal of the cilia with chloral hydrate and during ciliary regrowth to study the electrical properties of that portion of the surface membrane enclosing the ciliary axoneme. Removal of the somatic cilia (a 50% reduction in membrane surface area) resulted in an almost complete elimination of the regenerative Ca response, all-or-none Ba2+ spike, and delayed rectification. A 2-fold increase in input resistance resulted from the 50% reduction in membrane surface area. The electrical properties remained unchanged, despite prolonged exposure to the chloral hydrate, until the cilia were mechanically removed. Restoration of the Ca response accompanied ciliary regrowth, so that complete excitability returns when the cilia regain their original lengths. The voltage-sensitive Ca channels are localized to that portion of surface membrane surrounding the cilia. Measurements of membrane constants before and after deciliation and estimations of the cable constants of a single cilium suggest that Paramecium cilia may be fully isopotential along their length and with the major cell compartment.