DETECTION OF LIGHT-INDUCED-CHANGES OF INTRACELLULAR IONIZED CALCIUM CONCENTRATION IN LIMULUS VENTRAL PHOTORECEPTORS USING ARSENAZO III
DETECTION OF LIGHT-INDUCED-CHANGES OF INTRACELLULAR IONIZED CALCIUM CONCENTRATION IN LIMULUS VENTRAL PHOTORECEPTORS USING ARSENAZO III
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DOI：
10.1113/jphysiol.1977.sp011814
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发表时间：
1977-01-01
影响因子：
5.5
通讯作者：
PINTO, LH
中科院分区：
文献类型：
--
作者：
BROWN, JE;BROWN, PK;PINTO, LH
将金属显色指示染料偶氮胂Ⅲ注入L.通过扫描显微分光光度计测量单个暗适应细胞中染料的吸收光谱（450-750 nm）。当细胞对光适应时，染料吸收改变;差异光谱在λ处具有2个最大值。610和660 nm，在λ/λ处有宽的最小值。540 nm，等吸光点在λ585 nm。当在先前注射偶氮胂III的暗适应细胞中细胞内Ca浓度升高时，差谱在λ处具有2个最大值。610和660 nm，在λ/λ处有宽的最小值。530 nm，等吸光点在λ585 nm。将Mg 2+注射到先前注射有染料的暗适应细胞中诱导了在λ处具有单一最大值的差异光谱。620 nm。降低先前注射的细胞的细胞内pH诱导了在λ处具有最小值的差谱。620 nm。当鲎腹侧光感受器适应光时，细胞内Ca ~（2+）似乎升高。在腹侧光感受器中测量的光诱导差异光谱与在含有2 mM偶氮胂III的400 mM-KCl、1 mM-MgCl 2和25 mM MOPS [3-（N-吗啉代）丙磺酸]（pH 7.0）的微量比色皿中测定的标准曲线的比较中，光适应性光感受器中的细胞内Ca 2+浓度[Ca 2 +]i达到至少10-4 M。在注射了< 3 mM偶氮胂III的细胞中，光诱导了660 nm（T660）处光透射率的短暂降低，表明腹侧光感受器的照明通常会导致[Ca 2 +]i的短暂增加。偶氮胂III是敏感的，选择性和快速足够的测量光诱导的鲎腹侧感光细胞内Ca 2+的变化。
The metallochromic indicator dye arsenazo III, was injected intracellularly into L. polyphemus ventral photoreceptor cells to concentrations > 1 mM. The absorption spectrum (450-750 nm) of the dye in single dark-adapted cells was measured by a scanning microspectrophotometer. When a cell was light-adapted, dye absorption changed; the difference spectrum had 2 maxima at .apprx. 610 and 660 nm, a broad minimum at .apprx. 540 nm and an isosbestic point at .apprx. 585 nm. When intracellular Ca concentration was raised in dark-adapted cells previously injected arsenazo III, the difference spectrum had 2 maxima at .apprx. 610 and 660 nm, a broad minimum at .apprx. 530 nm and an isosbestic point at .apprx. 585 nm. The injection of Mg2+ into dark-adapted cells previously injected with dye induced a difference spectrum that had a single maximum at .apprx. 620 nm. Decreasing the intracellular pH of previously injected cells induced a difference spectrum that had a minimum at .apprx. 620 nm. There seems to be a rise of intracellular Ca2+ when a Limulus ventral photoreceptor is light-adapted. The intracellular Ca2+ concentration, [Ca2+]i, in light-adapted photoreceptors reached at least 10-4 M on comparison of light-induced difference spectra measured in ventral photoreceptors with a standard curve determined in microcuvettes containing 2 mM arsenazo III in 400 mM-KCl, 1 mM-MgCl2 and 25 mM MOPS [3-(N-morpholino)propane sulfonic acid] at pH 7.0. In cells injected with < 3 mM arsenazo III, light induced a transient decrease in optical transmission at 660 nm (T660), indicating that illumination of a ventral photoreceptor normally causes a transient increase of [Ca2+]i. Arsenazo III was sensitive, selective and rapid enough to measure light-induced changes of intracellular Ca2+ in Limulus ventral photoreceptor cells.