Tseng C C, Schmidt K L, Johnson L R
Am J Physiol. 1987 Sep;253(3 Pt 1):G284-9. doi: 10.1152/ajpgi.1987.253.3.G284.
The effect of corticosterone and thyroxine on the development of parietal cells was studied in 20-day-old rats. Either corticosterone or thyroxine injection significantly increased the amount of mitochondria, tubulovesicles, and intracellular canaliculi in normal rat pup parietal cells. However, the ultrastructure of parietal cells did not change when rats were adrenalectomized or made hypothyroid by propylthiouracil (PTU) during the first week of life. Corticosterone had the same effect in hypothyroid rats as in normal rats, increasing the volume fraction of mitochondria and the surface density of tubulovesicles and intracellular canaliculi in the parietal cell. However, thyroxine failed to do so in adrenalectomized animals. When 20-day-old adrenalectomized or hypothyroid rats were challenged with secretagogues, there was no increase in maximal acid output over the basal secretory rate, while normal rats showed a 40-50% increase. We conclude that 1) normal parietal cells respond to additional thyroxine or corticosterone with increases in volume fraction of mitochondria and surface density of tubulovesicles and intracellular canaliculi; 2) the dramatic decreases in acid secretion observed in adrenalectomized or PTU-treated rats are not explained by the morphology of parietal cells that remains normal; 3) the effect of thyroxine on the development of acid secretion is mediated by corticosterone; and 4) unlike chief cells the morphological development of parietal cells does not appear to depend on corticosterone or thyroxine after postnatal day 7.
在20日龄大鼠中研究了皮质酮和甲状腺素对壁细胞发育的影响。单独注射皮质酮或甲状腺素均能显著增加正常幼鼠壁细胞中线粒体、微管泡系统和细胞内小管的数量。然而，在出生后第一周对大鼠进行肾上腺切除或用丙硫氧嘧啶（PTU）使其甲状腺功能减退时，壁细胞的超微结构并未改变。皮质酮对甲状腺功能减退大鼠的作用与正常大鼠相同，可增加壁细胞中线粒体的体积分数以及微管泡系统和细胞内小管的表面密度。然而，甲状腺素对肾上腺切除的动物却没有这种作用。当用促分泌剂刺激20日龄肾上腺切除或甲状腺功能减退的大鼠时，其最大酸分泌量相对于基础分泌率并未增加，而正常大鼠则增加了40% - 50%。我们得出以下结论：1）正常壁细胞对额外的甲状腺素或皮质酮的反应是线粒体体积分数以及微管泡系统和细胞内小管表面密度增加；2）在肾上腺切除或PTU处理的大鼠中观察到的酸分泌显著减少，并非由保持正常的壁细胞形态所解释；3）甲状腺素对酸分泌发育的影响是由皮质酮介导的；4）与主细胞不同，壁细胞在出生后第7天之后的形态发育似乎不依赖于皮质酮或甲状腺素。
