title: Ticlopidine prevents the formation but delays the healing of ethanol-induced gastric lesions in the rat.
abstract: The effects of acute or long-term oral ticlopidine administration in normal rat gastric mucosa or on gastric lesions induced by ethanol 50% (EtOH, 1 ml/rat, os) were examined and compared with those of acetylsalicylic acid (ASA). Ticlopidine does not affect gastric mucosal integrity either after acute (100 and 300 mg kg(-1)) or 1-week (100 mg kg(-1), die) oral administration. Ticlopidine (30-300 mg kg(-1), os) administered 1h before EtOH dose-dependently prevented the development of gastric haemorragic lesions. When ticlopidine was administered 1h after EtOH, it significantly (p<0.05) delays gastric lesions healing. Acute ASA (50 and 100 mg kg(-1), os) administration causes a mild irritant activity similar to that observed after 1 week of ASA (50 mg kg(-1), os/die) administration. In condition of mucosal damage, ASA does not modify either the induction or the healing of EtOH-induced gastric lesions. To assess the possible involvement of endogenous nitric oxide (NO) or prostaglandins (PG) in the gastric protective activity of ticlopidine, the rats were pretreated with an inhibitor of NO-synthesis, L-NAME (70 mg kg(-1), s.c.) or the inhibitor of PG synthesis, indomethacin (Indo, 10 mg kg(-1), s.c.). Indo, but not L-NAME, was able to significantly counteract the gastroprotective activity of ticlopidine against EtOH injury. Furthermore, ticlopidine increases (47%) gastric PGE(2) content in normal mucosa compared to the one detected in control rats, thus suggesting that endogenous PGs contribute to enhanced mucosal resistance by ticlopidine. These results indicate that ticlopidine exerts dual effects during the development and healing of gastric lesions induced by EtOH.
authors.affiliation: Department of Pharmacology, Chemotherapy and Medical Toxicology, University of Milano, Italy. valeria.sibilia@unimi.it
authors.forename: V
authors.initials: V
authors.lastname: Sibilia
authors.forename: F
authors.initials: F
authors.lastname: Pagani
authors.forename: N
authors.initials: N
authors.lastname: Lattuada
authors.forename: V
authors.initials: V
authors.lastname: De Luca
authors.forename: F
authors.initials: F
authors.lastname: Guidobono
authors.forename: A
authors.initials: A
authors.lastname: Soglian
authors.forename: C
authors.initials: C
authors.lastname: Netti
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001241:Aspirin / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D015232:Dinoprostone / Q000378:metabolism; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D000431:Ethanol; D005753:Gastric Mucosa / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D007213:Indomethacin / Q000494:pharmacology; D008297:Male; D010438:Peptic Ulcer Hemorrhage / Q000209:etiology / Q000473:pathology / Q000503:physiopathology / Q000517:prevention & control*; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D051381:Rats; D017207:Rats, Sprague-Dawley; D013276:Stomach Ulcer / Q000150:complications / Q000188:drug therapy / Q000473:pathology / Q000503:physiopathology / Q000517:prevention & control*; D013988:Ticlopidine / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D013997:Time Factors; D014945:Wound Healing / Q000187:drug effects*
chemical_list: D016861:Cyclooxygenase Inhibitors; D010975:Platelet Aggregation Inhibitors; D000431:Ethanol; D015232:Dinoprostone; D013988:Ticlopidine; D001241:Aspirin; D007213:Indomethacin