Angiogenesis, cell proliferation and apoptosis in gastric ulcer healing. Effect of a selective cox-2 inhibitor Susana Sa ´nchez-Fidalgo a , Ine ´s Martı ´n-Lacave b , Matilde Illanes b , Virginia Motilva a, * a Department of Pharmacology, Faculty of Pharmacy, University of Seville, Spain b Department of Normal and Pathological Citology and Histology, Faculty of Medicine, University of Seville, Spain Received 27 September 2004; accepted 4 October 2004 Available online 30 October 2004 Abstract To elucidate the role of cyclooxygenase-2, we compared the effects of rofecoxib, a selective cyclooxygenase-2 inhibitor, and ibuprofen, a nonselective cyclooxygenase inhibitor, on the evolution of acetic-acid-induced gastric ulcers in rats, evaluating growth factor expression, the angiogenic process, cell proliferation and cell apoptosis. Levels of basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF), angiogenesis and cell proliferation were analysed by immunohistochemical methods, and apoptosis was evaluated by an enzyme immunoassay. Both growth factors and microvessels appeared to be abundant in the granulation tissue of the ulcer bed. Rofecoxib (2.5 mg/kg/day) and ibuprofen (100 mg/kg/day) delayed ulcer healing, but only rofecoxib treatment provoked a reduction of bFGF expression and inhibition of the development of new microvessels. No changes in VEGF expression were detected. Results also showed that proliferation and apoptosis were increased in control ulcerated animals. Rofecoxib reduced significantly both processes. These findings demonstrate that a reduction of bFGF expression and an antiangiogenic action, as well as proliferation/apoptosis inhibition, are some of the mechanisms possibly implicated in the delay in ulcer healing seen after the administration of the highly selective COX-2 inhibitor rofecoxib. D 2004 Elsevier B.V. All rights reserved. Keywords: NSAID; Rofecoxib; Ibuprofen; bFGF expression; VEGF expression; Apoptosis; Proliferation 1. Introduction The gastric mucosa is normally exposed to a wide range of aggressive insults and has developed efficient mechanisms to repair tissue injury. In the case of deeper mucosal damage, such as erosions and ulcers, both epithelial and connective tissue components, including subepithelial myofibroblasts, smooth muscle cells and vessels, are destroyed and must be regenerated (Milani and Calabro, 2001). The reconstitution of the surface epithelium is achieved by the proliferation of undifferentiated epithelial precursors that migrate from the ulcer margin onto the granulation tissue and cover the ulcer bed. Previous studies have suggested that the balance between cell apoptosis and cell proliferation is of great importance for maintaining gastric mucosa integrity (Reed, 2000). In addition to the epithelial structures, new vessels are generated to ensure an adequate supply of oxygen and nutrients to the healing mucosa (Tarnawski et al., 2001; Guo et al., 2002). The complex sequence of events requires a high degree of coordination and is regulated by several factors. Among them, polypeptide growth factors have received much attention in recent years because of their ability to regulate essential cell functions involved in tissue healing, including cell restoration, migration and angiogenesis (Szabo et al., 2000; Berenguer et al., 2002). Granulation tissue grows extensively under the control of basic fibroblast growth 0014-2999/$ - see front matter D 2004 Elsevier B.V. All rights reserved. doi:10.1016/j.ejphar.2004.10.019 * Corresponding author. Tel.: +34 954 556720; fax: +34 954 233765. E-mail address: motilva@us.es (V. Motilva). European Journal of Pharmacology 505 (2004) 187 – 194 www.elsevier.com/locate/ejphar