Differences in Gastroprotective Processes in 6- to 8- and 14- to 16-Week-Old Rats

摘要

The gastroprotective effect of opioid peptides, prostaglandin E2 and capsaicin against acidified ethanol-induced gastric mucosal damage in young mature rats of different (6–8 and 14–16 weeks) ages has been investigated. It was found that gastric mucosal damage was more severe in 14–16 weeks old rats. The gastroprotective effect of opioid peptides - [D-Ala2, D-Leu5]-enkephalin (DADLE), deltorphin II, [D-Ala2, Phe4, Gly5 -ol]-enkephalin (DAGO) and β-endorphin - given either intracerebroventricularly (0.6, 3.3., 0.2, and 0.01 nmol/rat, respectively) or subcutaneously (825 and 960 nmol/kg, respectively) was highly reduced in 14–16 weeks old rats. The mucosal protective action of orally administered capsaicin (1600–3200 nmol/kg) and PGE2 (280–560 nmol/kg) was also diminished in 14–16 weeks old animals. Both ACTH and corticosterone plasma levels were significantly higher in 14–16 weeks old rats. These results suggest that the gastric mucosal susceptibility to ethanol and the gastroprotective effect of opioid peptides, capsaicin and PGE2 are age-related.