Fykse V, Solligård E, Bendheim M Ø, Chen D, Grønbech J E, Sandvik A K, Waldum H L
Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway.
Acta Physiol (Oxf). 2006 Jan;186(1):37-43. doi: 10.1111/j.1748-1716.2005.01504.x.
Gastrin stimulates acid secretion by mobilizing histamine from enterochromaffin-like (ECL) cells that occur predominantly at the base of the gastric glands. The parietal cells occur higher up in the glands nearer to the gastric lumen. The present study was performed to assess whether histamine is transported from the ECL cell via the microcirculation (endocrine route) or local diffusion (paracrine route).
Totally isolated, vascularly perfused, rat stomachs were examined both in basal and gastrin-stimulated state. Histamine concentrations, determined by radioimmunoassay in venous effluent and microdialysate from an indwelling probe in the submucosa, were monitored over a period of 240 min. Gastrin-17 was infused through an arterial catheter for 120 min. The parietal cells were examined by electron microscopy, and the percentage of actively secreting parietal cells (displaying secretory canaliculi) in four regions along the glands (basal to surface, zones I-IV) was determined.
Gastrin stimulated acid secretion and histamine release as well as parietal cell activation. Upon gastrin stimulation, histamine concentration in the microdialysate was 2.5-fold higher than in the venous effluent (P = 0.008). The parietal cells in the upper part of the gland (zone III) were found to be activated the most.
As the histamine concentrations were higher in the tissue (microdialysate) than in blood, histamine seems to reach the parietal cells via the paracrine route. The fraction of active parietal cells seems to depend more on the age of the parietal cells than on the distance from the ECL cell.
胃泌素通过从主要位于胃腺底部的肠嗜铬样（ECL）细胞释放组胺来刺激胃酸分泌。壁细胞位于胃腺中更靠近胃腔的较高位置。本研究旨在评估组胺是通过微循环（内分泌途径）还是局部扩散（旁分泌途径）从ECL细胞转运而来。
对完全分离、进行血管灌注的大鼠胃在基础状态和胃泌素刺激状态下进行检查。通过放射免疫分析法测定静脉流出液和来自黏膜下留置探针的微透析液中的组胺浓度，并在240分钟内进行监测。通过动脉导管注入胃泌素-17，持续120分钟。通过电子显微镜检查壁细胞，并确定沿胃腺四个区域（从底部到表面，I-IV区）中活跃分泌的壁细胞（显示分泌小管）的百分比。
胃泌素刺激胃酸分泌、组胺释放以及壁细胞活化。在胃泌素刺激下，微透析液中的组胺浓度比静脉流出液中的高2.5倍（P = 0.008）。发现腺上部（III区）的壁细胞活化程度最高。
由于组织（微透析液）中的组胺浓度高于血液中的，组胺似乎通过旁分泌途径到达壁细胞。活跃壁细胞的比例似乎更多地取决于壁细胞的年龄，而不是与ECL细胞的距离。
