Hashimoto A, Hazama A, Kotera T, Ueda S, Okada Y
Department of Physiology, Kyoto University Faculty of Medicine, Japan.
Pflugers Arch. 1992 Oct;422(1):84-6. doi: 10.1007/BF00381517.
During acid secretion, gastric parietal cells undergo profound morphological changes including formation of the apical secretory membrane. To examine the mechanism of histamine-induced increases in the apical membrane area at the single cell level, we monitored the membrane capacitance by applying a time-resolved phase-sensitive detection method to singly isolated parietal cells of guinea pig. A real-time increase in the membrane capacitance was detected within several min after stimulation with histamine. An H2-blocker (cimetidine), but not an H1-blocker (pyrilamine), inhibited the histamine response. Dibutyryl cyclic AMP mimicked the histamine effect. The capacitance response to histamine was sensitive to cytosolic Ca2+, temperature and N-ethylmaleimide. The histamine response was inhibited by intracellular application of a non-hydrolyzable ATP analog (AMP-PNP) and an isoquinolinesulfonamide derivative that works as an inhibitor of protein kinase A (H-8). These results indicate that in parietal cells, elevation of intracellular cyclic AMP induces exocytotic insertion of intracellular membranes into the plasma membrane, presumably by activating protein kinase A.
在胃酸分泌过程中,胃壁细胞会发生深刻的形态变化,包括顶端分泌膜的形成。为了在单细胞水平上研究组胺诱导顶端膜面积增加的机制,我们通过将时间分辨相敏检测方法应用于豚鼠单个分离的胃壁细胞来监测膜电容。在用组胺刺激后几分钟内检测到膜电容的实时增加。H2受体阻滞剂(西咪替丁)而非H1受体阻滞剂(吡苄明)抑制了组胺反应。二丁酰环磷酸腺苷模拟了组胺的作用。对组胺的电容反应对胞质Ca2+、温度和N-乙基马来酰亚胺敏感。组胺反应被细胞内应用不可水解的ATP类似物(AMP-PNP)和作为蛋白激酶A抑制剂(H-8)的异喹啉磺酰胺衍生物所抑制。这些结果表明,在胃壁细胞中,细胞内环磷酸腺苷的升高可能通过激活蛋白激酶A诱导细胞内膜向质膜的胞吐插入。