细胞松弛素B和二甲亚砜对家兔胆囊体外等渗液体转运的影响。

Effects of cytochalasin B and dimethylsulphoxide on isosmotic fluid transport by rabbit gall-bladder in vitro.

作者信息

Frederiksen O, Leyssac P P

出版信息

J Physiol. 1977 Feb;265(1):103-18. doi: 10.1113/jphysiol.1977.sp011707.

DOI:10.1113/jphysiol.1977.sp011707

PMID:850153

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC1307810/

Abstract

Net fluid transport rate, transepithelial ohmic resistance and potential difference (p.d.), and unidirectional fluxes of Na+ were measured in rabbit gall-bladder preparations in vitro exposed on both sides to Ringer solutions of identical electrolyte composition. 2. Bilateral application of 1% dimethylsulphoxide (DMSO), the solvent for cytochalasin B, rapidly and reversibly depressed net fluid transport rate by 15% and increased the lumen positive p.d. by 1-5-2-0 mV. Resistance did not change significantly. These effects of DMSO were shown to be non-specific osmotic effects. 3. Cytochalasin B (10(-5)M) applied bilaterally caused: (a) a progressive inhibition of net fluid transfer rate to 40-50% of its control value within 60 min; the effect was partly reversible within 60 min and independent of the substrates glucose, glutamate and pyruvate; (b) a progressive depression of the mucosal-to-serosal Na+ flux within the first 30 min with no further change in the flux during the following 30 min of exposure to cytochalasin B; the effect was partly reversible within 70 min; (c) a rapid but moderate increase in the passive serosal-to-mucosal Na+ flux, which continued to increase gradually during the entire 60 min period of exposure to cytochalasin B; the effect was completely reversible within 70 min; (d) a prompt drop in ohmic resistance (30%) and p.d. (40%) with no further changes in these parameters during the following 60 min of exposure to cytochalasin B. The effect on resistance was partly reversible within 90 min; the effect on p.d. was completely reversible within 30 min. 4. The results are interpreted to indicate an early inhibitory action of cytochalasin B on the active transcellular pump mechanism and to suggest a cytochalasin B-mediated progressive increase in cell membrane permeability to sodium resulting ultimately in a highly leaky epithelium. The results are compatible with the concept that a mechanochemical process is involved in isosmotic transcellular transport of fluid across low-resistance epithelia.

摘要

在体外将兔胆囊制备物两侧暴露于电解质成分相同的林格氏溶液中，测量其净液体转运速率、跨上皮欧姆电阻和电位差（p.d.）以及Na⁺的单向通量。2. 双侧应用1%二甲基亚砜（DMSO），即细胞松弛素B的溶剂，迅速且可逆地使净液体转运速率降低15%，并使管腔正电位差增加1.5 - 2.0 mV。电阻无显著变化。DMSO的这些作用被证明是非特异性渗透作用。3. 双侧应用细胞松弛素B（10⁻⁵M）导致：（a）在60分钟内净液体转运速率逐渐抑制至其对照值的40 - 50%；该作用在60分钟内部分可逆，且与底物葡萄糖、谷氨酸和丙酮酸无关；（b）在最初30分钟内粘膜到浆膜的Na⁺通量逐渐降低，在随后暴露于细胞松弛素B的30分钟内通量无进一步变化；该作用在70分钟内部分可逆；（c）被动浆膜到粘膜的Na⁺通量迅速但适度增加，在暴露于细胞松弛素B的整个60分钟期间持续逐渐增加；该作用在70分钟内完全可逆；（d）欧姆电阻迅速下降（30%）和电位差下降（40%），在随后暴露于细胞松弛素B的60分钟内这些参数无进一步变化。对电阻的作用在90分钟内部分可逆；对电位差的作用在30分钟内完全可逆。4. 结果被解释为表明细胞松弛素B对主动跨细胞泵机制有早期抑制作用，并提示细胞松弛素B介导细胞膜对钠的通透性逐渐增加，最终导致上皮细胞高度渗漏。这些结果与以下概念相符，即机械化学过程参与了低电阻上皮细胞的等渗跨细胞液体转运。