Effect of H2-receptor antagonists on indomethacin-induced lysosomal enzyme release from rat gastric mucosa

The in vivo effect of indomethacin and three H 2 -receptor antagonists-cimetidine, ranitidine, and famotidine-on gastric damage and on the activity of lysosomal enzymes and on proteins was examined in rat gastric mucosa and serum. The activities of the lysosomal enzymes N-acetyl-beta-glucosaminidase (NAGA), acid phosphatase (APh), and beta-D-glucuronidase (GLU) decreased significantly in gastric mucosa 2, 4, 6 and 12 h after subcutaneous administration of indomethacin (20 mg/kg). The serum activities of the lysosomal enzymes were unchanged. A decrease of protein in gastric mucosa was observed 4 and 6 h after indomethacin administration. Pretreatment with cimetidine and ranitidine reduced dose-dependently the length of gastric lesions induced by indomethacin, as well as the decrease in lysosomal enzyme mucosal activities