Scanning Electron Microscopic Observations on Gastric Mucus Secretion in Rats, and the Effects of Tetraprenylacetone

Abstract

Mucus secretion in the gastric mucosa of rats was studied with a scanning electron microscope. After stimulation, two types of mucus secretion were observed: exocytosis and apical expulsion. Prolonged administration of tetraprenylacetone (TPA) significantly increased the number of mucus-secreting cells in both the gastric corpus and antrum 12 h after the last administration of TPA. In the secreting cells, apical expulsion was significantly more frequent among TPA-treated than in untreated rats. TPA also significantly increased the hexosamine concentration in both gastric corpus and antrum. These findings indicate that TPA stimulates both the content and the secretion of gastric mucus, and that its secretion is chiefly through apical expulsion.

Cellular pathology of experimental colitis induced by trinitrobenzenesulphonic acid (TNBS): Protective effects of recombinant human interleukin-11

“…This action ofrhlL-11 on mucus release was present whether or not TNBS had been administered to induce colitis and was reflected by simple exocytosis and compound exocytosis [33], in the latter ofwhich aggregates ofmucous granules are released together. This action of rhlL-I 1 was similarto the enhanced mucus secretion observed on the gastric mucosal surface, assessed by scanning electron microscopy, as stimulated by the antiulcer drug, tetraprenylacetone, in the rat [34], oras stimulated by the gastroprotective actions of zinc acexamate [35]. Mucus glycoprotein, secreted by both exocytosis and apical expulsive mechanisms, has long been associated with gut mucosal defence mechanisms [36] and is also enhanced clinically in human patients with IBD.…”

Comparison of the Effectiveness of Geranylgeranylacetone with Cimetidine in Gastritis Patients with Dyspeptic Symptoms and Gastric Lesions: A Randomized, Double-Blind Trial in Japan

“…There have been numerous reports indicating that GGA exerts its mucoprotective effects through the induction of HSP and the stimulation of mucin secretion in the gastric mucosa [9,10,11,24,25,26]. GGA is an acyclic polyisoprenoid compound that protects against gastric injury induced by cold or water-immersion restraint stresses, and by non-steroidal anti-inflammatory drugs [10,27,28].…”

Protective Effect of Teprenone Against Acute Gastric Mucosal Lesions Induced by Compound 48/80, a Mast Cell Degranulator, in Rats

“…However, the drug has no activity to scavenge ROS and to inhibit lipid peroxidation in vitro, as described above. Teprenone is known to stimulate gastric mucus synthesis and secretion through a nitric oxide (NO)-dependent pathway (7,8). Therefore, we examined a possibility that the preventive effect of pre-administered teprenone on the increase in gastric mucosal TBARS content in compound 48 / 80-treated rats is due to the indirect antioxidant action of the drug, that is, the ROS scavenging action of gastric mucus increased through the NO-mediated stimulatory action of the drug on gastric mucus synthesis and secretion.…”

“…This drug is clinically used for treatments of gastric ulcers and gastritis (1 -3). Teprenone is known to stimulate gastric mucus synthesis and secretion in rat gastric cultured cells (4 -6) and in gastric tissues of rats (7,8). This drug is also known to increase gastric mucus level in the ulcerated and intact regions of the stomach of patients (9).…”