The effect of portal hypertension on expression of gastric mucin mRNA in rats

Background/Aims: Gastric mucin, a principal component of gastric mucus, is thought to play an important role in protecting gastric mucosa and maintain ing the homeostasis of the gastric mucosa. Our previous studies have demons trated that the contents of gastric mucin were decreased in rats with porta l hypertension. Thus, the purpose of this present study was designed to con firm the effect of portal hypertension on the expression of gastric mucin m RNA and to localize gastric mucin mRNA production site in rats. Methodology: Portal hypertension was induced experimentally by partial liga tion of the portal vein in Wistar rats. The severity of gastric mucosal les ions was evaluated macroscopically by a gross ulcer index. We simultaneousl y measured the levels of mRNA in the gastric tissues of control and portal hypertension rats by reverse transcription-polymerase chain reaction, South ern blot hybridization, and in situ hybridization. Results: The damage to gastric mucosa was found to be prominently greater i n the portal hypertension rats compared to the control (P <0.01). The expre ssion of mucin mRNA was significantly reduced in portal hypertension rats c ompared to the control using the reverse transcription-polymerase chain rea ction and Southern blot hybridization (both P <0.01). In situ hybridization showed that mucin mRNA was localized primarily in the gastric submucosa an d mucosa; particularly in the surface mucous and the gland mucous cells. Conclusions: Our results reveal that portal hypertension would cause a decr ease in mucin mRNA, and it would be helpful in understanding the mechanism of gastric mucosal mucin alteration in portal hypertension and the pathogen esis of portal hypertension gastropathy. Furthermore, it may provide the st rategy in the prevention and therapy of portal hypertension gastropathy.