[Effects of acid secretagogues on rat gastric mucus glycoprotein content and gastric mucosal resistance]

In our previous reports, low dose acid secretagogues caused increase in corpus mucus glycoprotein content in rats. This increase was not due to the direct action of protons. The present study was conducted to determine whether this increase has a mucosal function or not Rats were given histamine (0.8 mg/kg) intraperitoneally or tetragastrin (12 micrograms/kg) subcutaneously. One hour following the acid secretagogues administration, the animals were given 1 ml of 30, 40 or 50% ethanol orally and then sacrificed after one hour. Gastric mucus glycoproteins were isolated from the corpus region of stomach. The following results were obtained: 1) Histamine prevented the gastric mucosal damage and the decrease of corpus mucus glycoprotein content induced by 40% ethanol ingestion. 2) Tetragastrin prevented the gastric mucosal damage induced by 30 approximately 50% ethanol ingestion and the decrease of corpus mucus glycoprotein content induced by 40 approximately 50% ethanol ingestion. Based on these results, the increase of corpus mucus glycoprotein content induced by acid secretagogues has a mucosal function. Moreover, tetragastrin strengthened the mucosal defence together with acid secretion.