心房钠尿肽合成细胞在大鼠胃黏膜超微结构定位及与微血管密度的相关性

背景:研究证实心房钠尿肽受体在大鼠胃的不同分区其分布密度不尽相同,其可抑制大鼠、豚鼠和人胃平滑肌的自发性收缩.目的: 探讨心房钠尿肽合成细胞在大鼠胃黏膜的超微结构定位及与微血管密度的相关关系.设计:单一样本观察.单位:承德医学院附属医院.材料:清洁级成年雄性Wistar大鼠18只,体质量300～350 g.方法: 实验于2004-10/2007-07在承德医学院中药研究所免疫学实验室完成.用包埋后免疫胶体金标记的电镜技术对大鼠胃黏膜心房钠尿肽-合成细胞进行超微结构定位,用组织化学藏红花-甲苯胺蓝染色对心房钠尿肽-合成细胞进行标记,同时用单宁酸-氧化铁和扫描电镜技术对大鼠胃黏膜的微血管进行观察.主要观察指标:①心房钠尿肽合成细胞的在大鼠胃内的超微结构定位.②微血管在大鼠胃黏膜的分布特点.③心房钠尿肽合成细胞的在大鼠胃黏膜的分布.④心房钠尿肽合成细胞与胃黏膜中微血管分布的相关关系.结果:①大鼠胃黏膜心房钠尿肽-合成细胞超微结构定位:证实心房钠尿肽-合成细胞为胃黏膜的肠嗜铬细胞.②大鼠胃黏膜的微血管观察结果:在胃黏膜的不同切面上微血管在腺体间弯曲走行在不同的切面上显示出三维结构,在胃黏膜的基底部微血管的密度最大.③心房钠尿肽合成细胞的在大鼠胃黏膜的分布:证实肠嗜铬细胞是胃黏膜的唯一嗜铬细胞,胞浆内有棕色颗粒,而在黏膜下和肌层中没有这种细胞分布,肠嗜铬细胞在不同的分布区域其分布密度不相同,分布密度最大在贲门区,其次是幽门区和胃底区,其分布密度排列顺序依次是:贲门区＞幽门区＞胃底区.④心房钠尿肽合成细胞与胃黏膜中微血管分布的相关关系:在大鼠胃贲门区两者呈正相关 (r =0.53,P ＜ 0.05,n=18);而在幽门区没有相关关系(r=0.38,P ＞ 0.05,n=18);在胃底区亦没有相关关系(r=-0.29,P ＞ 0.05,n=18).结论: 心房钠尿肽-合成细胞是胃黏膜的肠嗜铬细胞,心房钠尿肽-合成细胞和微血管在大鼠胃贲门区二者呈正相关,而在幽门区和胃底区没有相关性.

Ultrastructural localization of atrial natriuretic peptide-synthesizing cells in rat gastric mucosa and the correlation of atrial natriuretic peptide-synthesizing cells to microvessel density

BACKGROUND: Previous studies have confirmed that atrial natriuretic peptide (ANP) exists in different regions of rat gastric mucosa in different densities, and ANP can inhibit the spontaneous contraction of gastric smooth muscles in rat, guinea pig and human.OBJECTIVE: To investigate the ultrastructural localization of ANP-synthesizing cells and the correlation between ANP-synthesizing cells and microvessel density in rat gastric mucosa.DESIGN: Single sampling study.SETTING: Affiliated Hospital of Chengde Medical College. MATERIALS: Eighteen adult male Wistar rats of clean grade, weighing 300-350 g, were used in this study.METHODS: This study was conducted in the Laboratory of Chinese Materia Medica Immunology, Chengde Medical College from October 2004 to July 2007. The ultrastructural localization of ANP-synthesizing cells in rat gastric mucosa was performed by postembedding immunoelectron microscopy technique. The area density of ANP-synthesizing cell distribution was calculated by histochemical technique (saffron solution and toluidine solution staining included). Microvessels of rat gastric mucosa were revealed distinctively by tannic acid-ferric chloride staining method and scanning electron microscope technique.MAIN OUTCOME MEASURES:①The ultrastructural localization of ANP-synthesizing cells in rat gastric mucosa.②The distribution characteristics of gastric microvessels in different regions of rat gastric mucosa.③The distribution characteristics of ANP-synthesizing cells in rat gastric mucosa.④Correlation between ANP-synthesizing cell distribution and microvessel density.RESULTS: ① Ultrastructural localization of ANP-synthesizing cells: It was confirmed that ANP-cells were the enterochrochromaffin (EC) cells. ② Observation of microvessels: The microvessels were stained successfully by tannic acid-ferric chloride and scanning electron microscope technology. Microvessels of gastric mucous were in wriggled way and cut in different cross-sections. They could be clearly observed in distinct three-dimensions. The microvessel density was the largest in the basal glands of rat gastric mucous. ③ Distribution of ANP-synthesizing cells: It was identified that EC cell was only a chromaffin cell in the rat gastric mucosa. The chromaffin granules (brown granules) were localized in the cytoplasm of EC cells. Negative staining for chromaffin granules was detected in the submucosa and smooth muscle. EC cells had different distribution densities in different regions. The density order of EC cells was gastric cardiac region ＞ gastric pyloric region ＞ gastric fundic region in mucosal layer. ④ Correlation between ANP-synthesizing cells and microvessel density: Correlation analysis showed that there was a positive correlation between ANP-synthesizing cells and microvessel density in the gastric cardiac region(r = 0.53, P ＜ 0.05, n=18), and there was a negative correlation between above-mentioned two indices in the gastric pyloric region(r = 0.38, P ＞ 0.05 , n=18)and in the gastric fundic region(r = -0.29, P ＞ 0.05, n=18).CONCLUSION: ANP-synthesizing cells are the EC cells of gastric mucosa. There is a positive correlation between ANP-synthesizing cells and microvessels in the rat gastric cardiac region, while there is a negative correlation between ANP-synthesizing cells and microvessels in the rat gastric pyloric region and in the gastric fundic region.