Karasawa H, Tani N, Miwa T
Department of Internal Medicine, Tokai University School of Medicine, Isehara, Japan.
Gastroenterol Jpn. 1988 Feb;23(1):1-8. doi: 10.1007/BF02918848.
This study was designed to compare the effects of omeprazole and cimetidine on ultrastructural changes in parietal cells of guinea pigs during histamine stimulation. Both omeprazole and cimetidine remarkably inhibited acid secretion induced by histamine stimulation. Omeprazole, however, failed to prevent the morphological transition of parietal cells to an active stage during histamine stimulation, in contrast to cimetidine which inhibited the morphological transition. In addition, it was noticed that administration of omeprazole caused vacuolation in approximately 27% of all parietal cells. This phenomenon was not seen in control animals with histamine stimulation alone and only very rarely in cimetidine treated animals. Ultrastructural findings suggested that vacuoles originated in secretory canaliculi of parietal cells. These results may be the key to explain the difference of the inhibitory mechanism between omeprazole which acts on the final step of intracellular process (so-called proton pump) and cimetidine which acts on the H2-receptor site of plasma membrane.
本研究旨在比较奥美拉唑和西咪替丁对组胺刺激期间豚鼠壁细胞超微结构变化的影响。奥美拉唑和西咪替丁均能显著抑制组胺刺激诱导的胃酸分泌。然而，与抑制形态转变的西咪替丁不同，奥美拉唑未能阻止组胺刺激期间壁细胞向活跃阶段的形态转变。此外，还注意到给予奥美拉唑会导致约27%的壁细胞出现空泡化。这种现象在仅接受组胺刺激的对照动物中未观察到，在西咪替丁治疗的动物中也很少见。超微结构研究结果表明，空泡起源于壁细胞的分泌小管。这些结果可能是解释作用于细胞内过程最后一步（所谓的质子泵）的奥美拉唑和作用于质膜H2受体位点的西咪替丁之间抑制机制差异的关键。
