Im W B, Davis J P, Blakeman D P
Biochem Biophys Res Commun. 1985 Sep 16;131(2):905-11. doi: 10.1016/0006-291x(85)91325-7.
Gastric heavy microsomal membranes highly enriched in (H+-K+)-ATPase were obtained from cimetidine- or carbachol-treated rats through 2H2O and Percoll gradient centrifugations. Both the resting (cimetidine-treated) and the stimulated (carbachol-treated) heavy membranes which presumably represent the apical membrane of gastric parietal cells were enriched with the polypeptides of 81,000 and 45,000 besides that of 93,000 representing (H+-K+)-ATPase. No apparent differences could be detected between the resting and the stimulated heavy membranes in their polypeptide profiles or their specific activity of (H+-K+)-ATPase. Nevertheless, the level of 86RbCl uptake was greater in the stimulated than the resting heavy microsomal membrane vesicles. The light gastric microsomes which abound in intracellular tubulovesicles containing reserve (H+-K+)-ATPase as isolated from cimetidine-treated rats were similarly purified with respect to (H+-K+)-ATPase. The purified light gastric membranes were largely devoid of the polypeptides of 81,000 and 45,000 found in the heavy gastric membranes. These observations further support the current hypothesis that secretagogues bring about changes in the environment of (H+-K+)-ATPase and induce KCl permeability in the apical membrane of the parietal cells, although at present we have been unable to identify the polypeptide(s) responsible for the KCl pathway.
通过2H2O和Percoll梯度离心从西咪替丁或卡巴胆碱处理的大鼠中获得高度富集（H + -K +）-ATP酶的胃重微粒体膜。静息（西咪替丁处理）和刺激（卡巴胆碱处理）的重膜，可能代表胃壁细胞的顶端膜，除了代表（H + -K +）-ATP酶的93,000多肽外，还富含81,000和45,000的多肽。在静息和刺激的重膜之间，其多肽谱或（H + -K +）-ATP酶的比活性没有明显差异。然而，刺激的重微粒体膜囊泡中86RbCl的摄取水平高于静息的。从西咪替丁处理的大鼠中分离出的富含储备（H + -K +）-ATP酶的细胞内微管泡丰富的轻胃微粒体，在（H + -K +）-ATP酶方面也进行了类似的纯化。纯化的轻胃膜在很大程度上没有重胃膜中发现的81,0ousand和45,000的多肽。这些观察结果进一步支持了目前的假设，即促分泌剂会引起（H + -K +）-ATP酶环境的变化，并诱导壁细胞顶端膜中的KCl通透性，尽管目前我们还无法确定负责KCl途径的多肽。
