Acid-Induced Gastric Damage in Rats Is Aggravated by Starvation and Prevented by Several Nutrients

Abstract

The aggravation of acid-induced gastric damage and its prevention by glucose, ascorbate or glutathione precursors was studied in fed and food-deprived rats. The stomachs of fed rats and those starved for 1, 3 or 5 d were vagotomized just before irrigating for 3 h with solutions containing 0-150 mmol HCl/L. Mucosal glutathione, mucus, lipid peroxides and acid back-diffusion were measured. Stomach ulcers were evaluated by morphological and histological examination. The preventive effects of glucose, ascorbate and a mixture of L-glutamine, L-glycine and L-cysteine were evaluated in the stomachs of rats that were starved for 5 d, vagotomized, then perfused for 3 h with 100 mmol HCl/L. Greater acid back-diffusion and ulcer formation, and lower glutathione and mucus levels in starved rats were dependent on the duration of starvation and luminal acidity. Increased acid back-diffusion and decreased glutathione and mucus production were negatively correlated (r < −0.80, P < 0.05) with ulcer formation. A significant enhancement in mucosal lipid peroxide concentration and serious damage of forestomach and corpus mucosal cells were observed in starved rats exposed to 100 mmol HCl/L. These ulcerogenic factors were effectively inhibited in acid-perfused stomachs of food-deprived rats by daily intraperitoneal injection of the amino acid mixture (150 mg/kg) or by an average daily consumption via drinking water of glucose (10 g) or ascorbate (1.2 g). Starvation aggravated acid-induced gastric damage and was associated with greater acid back-diffusion and oxygen radical generation, and lower mucosal glutathione and mucus production.