FUNCTIONAL DYMAMISM OF GASTRIC MUCOSA BY MEANS OF HIGH-PRESSURE FREEZING METHOD

为了阐明胃壁细胞的功能转化，我们最近建立了一种分离的大鼠胃粘膜模型，该模型的壁细胞表现出从活跃到静止的酸分泌的恢复过程。质子泵免疫组织化学染色显示，质子泵从顶端逐渐向胞浆移位。在超微结构水平上，顶膜随后内化到细胞质中，形成独特的五层膜。然后，他们形成了许多多层自噬小体，这些自噬小体被强烈标记为质子泵。壁细胞表现出发达的高尔基体和溶酶体室，涉及多层膜。这些发现为胃壁细胞向静息状态的功能转化提供了新的见解，阐明细胞动力学对于维持正常的胃上皮具有重要的临床病理意义。在刺激后分离的大鼠胃粘膜中，有大量细胞脱落到凹陷区的胃腔内。利用冷冻技术的优势，对脱落细胞的来源及其组织化学特征进行了研究。经鉴定，大部分脱落细胞为花生凝集素和抗质子泵抗体标记的壁窝细胞。定量分析证实，刺激后分离的胃粘膜脱落细胞数量随时间而增加。大部分脱落细胞对TUNEL染色和caspase-3等凋亡标志物呈阴性反应。在超微结构上，脱落的顶窝细胞中常可见由质子泵阳性膜组成的自噬体样结构。此外，凹-壁细胞的脱落伴随着它们的基底部与相邻表面粘液细胞的细胞质突起的封闭。

To elucidate a functional transformation of gastric parietal cells, we have newly developed an isolated rat gastric mucosa model whose parietal cells exhibited a reverting process from the active to the resting state of acid secretion. Immunohistochemistry of proton pump demonstrated a progressive translocation of proton pump from the apical to the cytoplasmic region. At the ultrastructural level, the apical membranes were subsequently internalized into the cytoplasm forming unique penta-laminar membranes. They then formed a number of multilamellar autophagosomes that were intensely labeled for proton pump. The parietal cells exhibited well-developed Golgi apparatus and lysosomal compartments involving the multilamellar membranes. The present findings provide new insights into the functional transformation in gastric parietal cells reverting to their resting conformation.It is clinicopathologically important to elucidate the cell kinetics for the maintenance of normal gastric epithelium. In rat gastric mucosa isolated after stimulation, a number of cells were exfoliated into the gastric lumen of the pit region. It was undertaken to clarify the origin of exfoliated cells and their histochemical profiles by taking the advantages of cryotechniques. Most of the exfoliated cells were identified as pit-parietal cells labeled with both peanut-lectin and anti-proton pump antibody. Quantitative analysis verified a time-dependent increase in the number of exfoliated cells in the gastric mucosa isolated after stimulation. Most of the exfoliated cells were negative to the apoptotic markers such as TUNEL staining and caspase-3. Ultrastructurally, autophagusome-like structures consisting of proton pump positive membranes were frequently seen in the exfoliated pit-parietal cells. In addition, the pit-parietal cell exfoliation was accompanied by sealing of their basal portion with the cytoplasmic processes of adjacent surface mucous cells.