Intracellular ion concentrations in the isolated frog skin epithelium: evidence for different types of mitochondria-rich cells.
Intracellular ion concentrations in the isolated frog skin epithelium: evidence for different types of mitochondria-rich cells.
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分离的青蛙皮肤上皮细胞内离子浓度：不同类型富含线粒体的细胞的证据。
DOI：
10.1007/bf00231510
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发表时间：
1992
期刊：
影响因子：
--
通讯作者：
Rick,R
中科院分区：
文献类型：
--
作者：
Rick,R
用电子探针技术测定了尖音蛙剖皮细胞内离子浓度。在对照条件下，主细胞和富钙细胞（MR细胞）具有相似的细胞内离子组成，只有MR细胞中的Cl浓度显著较低。低浓度哇巴因（2 × 10− 6 m，内浴）抑制跨上皮Na转运导致主细胞的Na浓度从10.9 mmol/kg湿重增加到54.3 mmol/kg湿重。同时应用阿米洛利（10 - 4 m，外浴）可完全消除这种增加。阿米洛利单独导致Na浓度显著降低至6.1 mmol/kg。W. W.在MR细胞中，可以区分两组不同的细胞;哇巴因后Na增加的细胞，其甚至大于主细胞和对哇巴因没有反应的细胞。在所有哇巴因敏感的MR细胞中，约有一半的Na增加可以被阿米洛利阻止。根据这些结果，MR细胞的亚群显示预期的跨上皮Na转运室，顶端阿米洛利敏感的Na流入和abasal哇巴因可耐受的Na流出的运输特性。然而，鉴于细胞数量较少，这种MR细胞亚型不太可能对跨上皮Na转运的总体速率有显著贡献。
Intracellular ion concentrations were determined in split skins of Rana pipiens using the technique of electron microprobe analysis. Under control conditions, principal cells and mitochondria-rich cells (MR cells) had a similar intracellular ion composition, only the Cl concentration in MR cells was significantly lower. Inhibition of transepithelial Na transport by low concentrations of ouabain (2 × 10−6m, innerbath) resulted in a Na concentration increase of principal cells from 10.9 to 54.3 mmol/kg wet wt. The increase was completely abolished by simultaneous application of amiloride (10−4m, outer bath). Amiloride alone resulted in a significant decrease of the Na concentration to 6.1 mmol/kg. w. w. Among MR cells, two different groups of cells could be distinguished; cells that showed a Na increase after ouabain which was even larger than that in principal cells and cells that did not respond to ouabain. In about half of all ouabain-sensitive MR cells the Na increase could be prevented by amiloride. According to these results, a subpopulation of MR cells displays the transport characteristics expected for a transepithelial Na transport compartment, an apical amiloride-sensitive Na influx and abasal ouabain-inhibitable Na efflux. Given the small number of cells, however, it is unlikely that this subtype of MR cells contributes significantly to the overall rate of transepithelial Na transport.