Robert A, Nezamis JE, Lancaster C, Hanchar AJ: Cytoprotection by prostaglandins in rats prevention of gastric necrosis produced by alcohol, HCl, NaOH, hypertonic NaCl and thermal injury. These results suggest that (1) the bandlike pattern of AE-induced injury is dependent on the presence of mucosal folds (distending the stomach abolishes mucosal folds and widespread injury results) (2) 16,16-dm PGE 2 prevented the fold-related, bandlike lesions and bandlike staining of the mucosa, but failed to abolish the generalized lesions and (3) PG cytoprotection appears associated with the formation of bandlike lesions which are dependent on the presence of mucosal folds. 16,16-dm PGE 2 also significantly prevented the localized staining pattern seen in intact rats. Oral gentian violet (2 ml, 0.3% w/v) produced bandlike staining of the mucosa in intact rats, but the effect was blocked by pyloric ligation. This agent (10 μg/kg) had a slight effect on the reduction of PD caused by 10-min exposure of the stomach to AE (2 ml) in the intact stomach, while such effects were not apparent in the pylorus-ligated stomach.
16,16-dm PGE 2 (0.3–10 μg/kg, subcutaneous) dose dependently reduced bandlike lesions in the intact stomach, but had no or little effect on non-band-like lesions in the pylorus-ligated stomach. One milliliter produced bandlike lesions, whereas 2 ml or more induced widespread lesions such volumes were observed to remove the mucosal folds. AE produced elongated bands of hemorrhagic necrosis within 1 hr in the former, while in the pylorus-ligated stomach the shape of lesions varied depending upon the volume of irritant. AE (50% ethanol in 150 mM HCl) was given by gavage in the intact stomach or through a fistula prepared in the forestomach in the pylorus-ligated stomach. The effects of gastric distension on the morphology of acidified ethanol (AE) -induced mucosal lesions and on the protective action of 16,16-dm PGE 2 were investigated in rats.
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