Gastric mucus and mucosal glycoproteins (MUC5AC/MUC6)

Gastric mucus and mucosal glycoproteins, primarily Mucin-5AC (MUC5AC) and Mucin-6 (MUC6), constitute the primary physical barrier protecting the stomach lining from autodigestion by gastric acid and pepsin (StatPearls, 2023). MUC5AC is secreted by surface mucous cells, while MUC6 is produced by mucous neck cells, together forming a viscoelastic gel that traps bicarbonate ions to maintain a near-neutral pH at the epithelial surface (PubMed, PMID: 15153509). In pathological states such as peptic ulcer disease or Helicobacter pylori infection, the integrity of this glycoprotein matrix is often compromised, leading to mucosal erosion and inflammation (NIH, 2022). Therapeutic agents known as cytoprotective drugs, including sucralfate and rebamipide, interact with these glycoproteins to reinforce the barrier or stimulate their synthesis (PubChem, CID 5284595). Sucralfate, for instance, forms a polyanionic complex that binds to positively charged proteins and glycoproteins within ulcerated tissue, creating a protective bandage against further chemical injury (StatPearls, 2023).

Other names

Gastric mucinGastric mucus barrierMucin-5ACMucin-6Surface mucous cell mucinGlandular mucous cell mucin

Binding to mucosal glycoproteins to form a protective physical barrier; stimulation of endogenous prostaglandin-mediated mucus and bicarbonate secretion; enhancement of glycoprotein synthesis and sulfation to improve gel viscosity (StatPearls, 2023; PubMed, PMID: 15153509).