Na^+-K^+-2Cl^-共转运体不同亚型在大鼠胃黏膜的差异性分布及表达

Differential Expression of NKCC1 and NKCC2 in Rat Gastric Mucosa

目的研究Na+-K+-2Cl-共转运体(Na+-K+-2Cl-co-transporter,NKCC)的两种亚型在胃不同部位黏膜层的差异性分布及表达的意义。方法用免疫荧光组织化学法和实时定量PCR技术检测NKCC不同亚型NKCC1与NKCC2在正常大鼠胃不同部位(胃底、胃体和胃窦)黏膜组织的分布和表达。结果①免疫荧光组织化学显示:NKCC1多分布于胃底、胃窦黏膜底部及胃体黏膜中下部,细胞膜表达最多;而NKCC2则多分布于胃体、胃窦黏膜全层及胃底黏膜上1/3部,细胞质、细胞膜均有表达。②实时定量PCR显示:NKCC1的mRNA在正常大鼠胃体表达最高,NKCC2的mRNA则在胃窦表达最高。结论正常大鼠NKCC1与NKCC2在不同部位胃黏膜上皮细胞的分布及表达含量不同,NKCC1多分布在黏膜底部或中下部,NKCC2多分布于黏膜顶部或全层。

Objective To investigate differential distribution and gene content of two isoforms of Na＋-K＋-2Cl-co-transporter（NKCC）,NKCC1 and NKCC2 in rat gastric mucosa. Methods Immunofluorescence and real-time PCR were used to investigate the distribution and expression of NKCC1 and NKCC2 in different parts of stomach（gastric fundus,corpus and antrum）. Results ① NKCC1 immunoactivity in the gastric mucosa was found in the bottom part of gastric fundus and antrum,and middle and bottom mucosa of gastric corpus of rats,and cell membrane showed strong NKCC1 labeling.NKCC2 distributed across the full-thickness mucosa of gastric corpus and antrum but in the upper 1/3 mucosa of gastric fundus of rat,and it was dispersed in the cytoplasm and cell membrane.② Real-time PCR indicated that the mRNA of NKCC1 expressed mostly in the gastric corpus,however,the mRNA of NKCC2 expressed mostly in the gastric antrum. Conclusion In normal rats,the two isoforms of NKCC showed differential distribution and mRNA expression in the gastric mucosa;NKCC1 distributed mostly in the bottom or middle and bottom part of gastric mucosa,NKCC2 distributed mostly in the upper or full-thickness of gastric mucosa.