title: Contributions of physical and chemical properties of mild irritants to gastric cytoprotection in rats.
abstract: The present study demonstrated the cytoprotective abilities of low concentrations of ethanol, NaCl and HCl, against the gastric mucosal damage caused by 100% ethanol, and the contributions of the physical and chemical properties of these mild irritants to their protective actions. The results have shown the differential protective effects of ethanol (10-40%), NaCl (2.5-12.5%) and HCl (0.15-0.45M), with the optimal cytoprotective concentrations being 20% ethanol, 5% NaCl and 0.3M HCl, respectively. Solutions of KCl and NaCl with similar osmolarity, and H2SO4 and HCl of similar acidity and osmolarity, all showed similar protective protective potentials as compared to the osmotic agent mannitol, which possessed a concentration- and tonicity-dependent protective action against 100% ethanol-induced mucosal damage. Some concentration of methanol, propan-2-ol and ethanol, having similar osmolarity with deionized water, exerted indifferent protective effects. It is therefore concluded that adaptive cytoprotection induced by low concentrations of NaCl and HCl could depend on their physical properties, while that of ethanol could act through its unique chemical property.
authors.affiliation: Department of Pharmacology, Faculty of Medicine, University of Hong Kong.
authors.forename: J K
authors.initials: JK
authors.lastname: Ko
authors.forename: C H
authors.initials: CH
authors.lastname: Cho
authors.forename: S K
authors.initials: SK
authors.lastname: Lam
authors.forename: M W
authors.initials: MW
authors.lastname: Koo
authors.forename: C K
authors.initials: CK
authors.lastname: Ching
mesh_terms: D000818:Animals; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D003451:Cryoprotective Agents / Q000737:chemistry / Q000627:therapeutic use* / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D000431:Ethanol / Q000627:therapeutic use / Q000633:toxicity; D005753:Gastric Mucosa / Q000187:drug effects*; D006851:Hydrochloric Acid / Q000737:chemistry / Q000627:therapeutic use / Q000633:toxicity; D007509:Irritants / Q000737:chemistry / Q000627:therapeutic use* / Q000633:toxicity*; D008297:Male; D008353:Mannitol / Q000627:therapeutic use; D009994:Osmolar Concentration; D051381:Rats; D017207:Rats, Sprague-Dawley; D012965:Sodium Chloride / Q000737:chemistry / Q000627:therapeutic use / Q000633:toxicity; D013272:Stomach Diseases / Q000139:chemically induced / Q000517:prevention & control*
chemical_list: D003451:Cryoprotective Agents; D007509:Irritants; D000431:Ethanol; D008353:Mannitol; D012965:Sodium Chloride; D006851:Hydrochloric Acid