Studies have demonstrated that the prolonged use of corticoids can delay the healing process, affecting re-epithelialization, neovascularization and collagen synthesis. As the fins of teleost fish contain a large amount of collagen, the aim of the present study was to investigate the effect of dexamethasone (anti-inflammatory and glucocorticoid steroid widely used in the treatment of rheumatic diseases) during the regeneration process in the caudal fin of specimens of carp (Cyprinus carpio). For such, two glass aquaria were used – one for a group of fish treated with dexamethasone (Henrifarma) in a 20 mg/L concentration and the other for the control group. The caudal fins were amputated transversally and fish remained in their respective aquaria until regeneration occurred. Samples of regenerating fins were collected on days 1, 2, 4, 6, 8 and 10 after amputation. The fins in the control group regenerated normally and grew within the expected in time course. The fins in the group treated with dexamethasone were significantly smaller in comparison to the control group at every evaluation time. Thus, it was possible to verify that, at this concentration of dexamethasone, the regeneration of the caudal fins was delayed, but not completely inhibited. The results show that the caudal fin is a good model for histological studies on regeneration and the action of drug toxicity, but it’s also of great importance the interaction with further studies for a better knowledge and understanding of all the changes in all the phases. © 2015, Instituto Internacional de Ecologia. All rights reserved.752442450Akimenko, M.A., Marí-Beffa, M., Becerra, J., Géraudie, J., Old questions, new tools, and some answers to the mystery of fin regeneration (2003) Developmental Dynamics, 226 (2), pp. 190-201. , http://dx.doi.org/10.1002/dvdy.10248Arita, G.S., A re-examination of the functional morphology of the soft-rays in teleosts (1971) Copeia, 1971 (4), pp. 691-697. , http://dx.doi.org/10.2307/1442639Becerra, J., Junqueira, L., Bechara, I.J., Montes, G.S., Regeneration of fin rays in teleosts: A histochemical, radioautographic, and ultrastructural study (1996) Archives of Histology and Cytology, 59 (1), pp. 15-35. , http://dx.doi.org/10.1679/aohc.59.15, PMid:8727360Becerra, J., Montes, G.S., Bexiga, S., Junqueira, L., Structure of the tail fin in teleosts (1983) Cell and Tissue Research, 230 (1), pp. 127-137. , http://dx.doi.org/10.1007/BF00216033, PMid:6850759Bechara, I.J., Böckelmann, P.K., Montes, G.S., Cruz-Höfling, M.A., Inhibition of caudal fin actinotrichia regeneration by acetylsalicylic acid (Aspirin) in teleosts (2003) Brazilian Journal of Morphological Sciences, 20, pp. 67-74Bechara, I.J., Joazeiro, P.P., Marí-Beffa, M., Becerra, J., Montes, G.S., Collagen-affecting drugs impair regeneration of teleost tail fins (2000) Journal of Submicroscopic Cytology and Pathology, 32 (2), pp. 273-280. , PMid:11085216Blanc, M., Structure histologique des rayons de nageoires chez les poissons téléostéens (1947) Bulletin De La Société Zoologique, 72, pp. 17-22Böckelmann, P.K., Bechara, I.J., Effect of naproxen on tail fin regeneration in teleost (2004) Journal of Submicroscopic Cytology and Pathology, 36 (1), pp. 55-64. , PMid:15311675Böckelmann, P.K., Bechara, I.J., Histochemical and ultrastructural analysis of the action of naproxen on tail fin regeneration in carp (Cyprinus carpio) (2007) Brazilian Journal of Morphological Sciences, 24 (1), pp. 17-24Böckelmann, P.K., Ochandio, B.S., Bechara, I.J., Histological study of the dynamics in epidermis regeneration of the carp tail fin (Cyprinus carpio, Linnaeus, 1758) (2010) Brazilian Journal of Biology = Revista Brasileira De Biologia, 70 (1), pp. 217-223. , http://dx.doi.org/10.1590/S1519-69842010000100030, PMid:20231981Géraudie, J., Initiation of the actinotrichial development in the early fin bud of the fish, Salmo (1977) Journal of Morphology, 151 (3), pp. 353-361. , http://dx.doi.org/10.1002/jmor.1051510304, PMid:845969Géraudie, J., The fine structure of the early pelvic fin bud of the trouts Salmo gairdneri and S. Trutta fario (1978) Acta Zoologica, 59 (2), pp. 85-96. , http://dx.doi.org/10.1111/j.1463-6395.1978.tb00115.xGéraudie, J., Monnot, M.J., Brulfert, A., Ferretti, P., Caudal fin regeneration in wild type and long-fin mutant zebrafish is affected by retinoic acid (1995) The International Journal of Developmental Biology, 39 (2), pp. 373-381. , PMid:7669548Goodrich, E.S., On the dermal fin-rays of fishes - Living and extinct (1904) Journal of Microscopical Science, 47, pp. 465-522Goss, R., The natural history (And mystery) of regeneration (1991) A History Regeneration Research. Millestones in the Evolution of a Science, pp. 7-23. , In DINSMORE, CE. (Ed.), Cambridge: Cambridge University PressGoss, R.J., Stagg, M.W., The regeneration of fins and fin rays in Fundulus heteroclitus (1957) The Journal of Experimental Zoology, 136 (3), pp. 487-507. , http://dx.doi.org/10.1002/jez.1401360306, PMid:13525597Grassé, P., (1958) Rayons Des Nageoires, pp. 731-747. , GRASSÉ, P. Traité de zoologie. Paris: Éditions Masson. Tome XIII, Fascicule I-III, Traité de Zoologie, Anatomie, Systématique, BiologieGupta, A., Jain, G.K., Raghubir, R., A time course study for the development of an immunocompromised wound model, using hydrocortisone (1999) Journal of Pharmacological and Toxicological Methods, 41 (4), pp. 183-187. , http://dx.doi.org/10.1016/S1056-8719(99)00041-6, PMid:10691024Hay, E., (1966) Regeneration, p. 148. , Holt: Rinehart & WinstonJohnson, S.L., Weston, J.A., Temperature-sensitive mutations that cause stage-specific defects in Zebrafish fin regeneration (1995) Genetics, 141 (4), pp. 1583-1595. , PMid:8601496Kawashima, H., Ogose, A., Hayami, T., Yamagiwa, H., Hatano, H., Hotta, T., Endo, N., Effect of dexamethasone on growth inhibition and chondrogenic maturation of human chondrosarcoma (2003) Journal of Orthopaedic Science, 8 (3), pp. 341-345. , http://dx.doi.org/10.1007/s10776-003-0650-y, PMid:12768476Kemp, N.E., Park, J.H., Regeneration of lepidotrichia and actinotrichia in the tailfin of the teleost Tilapia mossambica (1970) Developmental Biology, 22 (2), pp. 321-342. , http://dx.doi.org/10.1016/0012-1606(70)90157-0Kiortsis, V., Trampusch, H., (1965) Regeneration in Animals and Related Problems, p. 568. , Amsterdam: North-Holland Publishing CompanyKrukenberg, C.F., Über die chemische Beschaffenheit der sog. Hornfaden von Mustelus und uber die Zusammensetzung der Keratinosen Hollen um die Eier von Scyllium stellate (1985) Mitt Zool Stat Neapel, 6, pp. 286-296Lanzing, W.J., The fine structure of fins and finrays of Tilapia mossambica (Peters) (1976) Cell and Tissue Research, 173 (3), pp. 349-356. , http://dx.doi.org/10.1007/BF00220323, PMid:991247Mabee, P.M., Crotwell, P.L., Bird, N.C., Burke, A.C., Evolution of median fin modules in the axial skeleton of fishes (2002) The Journal of Experimental Zoology, 294 (2), pp. 77-90. , http://dx.doi.org/10.1002/jez.10076, PMid:12210109Masaki, H., Ide, H., Regeneration potency of mouse limbs. Development (2007) Growth & Differentiation, 49 (2), pp. 89-98. , http://dx.doi.org/10.1111/j.1440-169X.2007.00909.x, PMid:17335430Mattson, P., (1976) Regeneration, p. 178. , Indianapolis: Bobbs-Merrill CompanyMiyazaki, Y., Tsukazaki, T., Hirota, Y., Yonekura, A., Osaki, M., Shindo, H., Yamashita, S., Dexamethasone inhibition of TGF beta-induced cell growth and type II collagen mRNA expression through ERK-integrated AP-1 activity in cultured rat articular chondrocytes. Osteoarthritis and cartilage/OARS (2000) Osteoarthritis Research Society, 8 (5), pp. 378-385. , http://dx.doi.org/10.1053/joca.1999.0313, PMid:10966845Muneoka, K., Bryant, S.V., Regeneration and development of vertebrate appendages (1984) Symposia of the Zoological Society of London, 52, pp. 177-196Muneoka, K., Holler-Dinsmore, G., Bryant, S.V., Intrinsic control of regenerative loss in Xenopus laevis limbs (1986) The Journal of Experimental Zoology, 240 (1), pp. 47-54. , http://dx.doi.org/10.1002/jez.1402400107, PMid:3772329Murciano, C., Pérez-Claros, J., Smith, A., Avaron, F., Fernández, T.D., Durán, I., Ruiz-Sánchez, J., Marí-Beffa, M., Position dependence of hemiray morphogenesis during tail fin regeneration in Danio rerio (2007) Developmental Biology, 312 (1), pp. 272-283. , http://dx.doi.org/10.1016/j.ydbio.2007.09.026, PMid:17977526Nechiporuk, A., Keating, M.T., A proliferation gradient between proximal and msxb-expressing distal blastema directs zebrafish fin regeneration (2002) Development, 129 (11), pp. 2607-2617. , PMid:12015289Oishi, Y., Fu, Z.W., Ohnuki, Y., Kato, H., Noguchi, T., Molecular basis of the alteration in skin collagen metabolism in response to in vivo dexamethasone treatment: Effects on the synthesis of collagen type I and III, collagenase, and tissue inhibitors of metalloproteinases (2002) The British Journal of Dermatology, 147 (5), pp. 859-868. , http://dx.doi.org/10.1046/j.1365-2133.2002.04949.x, PMid:12410694Ord, M.G., Stocken, L.A., Regeneration of urodele limbs (1984) Cell and Tissue Regeneration – a Biochemical Approach, pp. 21-37. , In ORD, MG. and STOCKEN, LA. (Eds.), Canadá: John Wiley & Sons, Cell Biology: A Series of MonographsPoss, K.D., Shen, J., Keating, M.T., Induction of lef1 during zebrafish fin regeneration (2000) Developmental Dynamics: An Official Publication of the American Association of Anatomists, 219 (2), pp. 282-286. , http://dx.doi.org/10.1002/1097-0177(2000)9999:9999<::AID-DVDY1045>3.3.CO;2-3, PMid:11002347Prenant, M., Structure fine et croissance normale des lepidotriciles articulés chez les téléostéens (1936) Comptes Rendus Des Seances De La Société De Biologie Et De Ses Filiales, 123, pp. 474-475Reynolds, J., Evaluated information on the world’s drugs and medicines (1996) Martindale – the Extra Pharmacopia, pp. 1042-1043. , In REYNOLDS, JEF. (Ed.), 31st ed. London: Royal Pharmaceutical SocietySantamaría, J.A., Marí-Beffa, M., Becerra, J., Interactions of the lepidotrichial matrix components during tail fin regeneration in teleosts (1992) DifferentiationResearch in Biological Diversity, 49 (3), pp. 143-150. , http://dx.doi.org/10.1111/j.1432-0436.1992.tb00662.x, PMid:1377652Su, S., Dehnade, F., Zafarullah, M., Regulation of tissue inhibitor of metalloproteinases-3 gene expression by transforming growth factor-beta and dexamethasone in bovine and human articular chondrocytes (1996) DNA and Cell Biology, 15 (12), pp. 1039-1048. , http://dx.doi.org/10.1089/dna.1996.15.1039, PMid:8985117Talas, D.U., Nayci, A., Atis, S., Polat, A., Comelekoglu, U., Bagdatoglu, C., Renda, N., The effects of corticosteroids on the healing of tracheal anastomoses in a rat model (2002) Pharmacological Research: The Official Journal of The Italian Pharmacological Society, 45 (4), pp. 299-304. , http://dx.doi.org/10.1006/phrs.2002.0964, PMid:12030793Tenius, F.P., Biondo-Simoes, M., Ioshi, S.O., Efeitos do uso crônico da dexametasona na cicatrização de feridas cutâneas em ratos (2007) Brazilian Annals of Dermatology, 82 (2)Weis, P., Weis, J.S., Effect of zinc on fin regeneration in the mummichog, Fundulus heteroclitus, and its interaction with methylmercury (1980) Fish Bulletin, 78, pp. 163-166Yin, V.P., Poss, K.D., New regulators of vertebrate appendage regeneration (2008) Current Opinion in Genetics & Development, 18 (4), pp. 381-386. , http://dx.doi.org/10.1016/j.gde.2008.06.008, PMid:18644447Yoshinari, N., Ishida, T., Kudo, A., Kawakami, A., Gene expression and functional analysis of zebrafish larval fin fold regeneration (2009) Developmental Biology, 325 (1), pp. 71-81. , http://dx.doi.org/10.1016/j.ydbio.2008.09.028, PMid:18950614Zodrow, J.M., Tanguay, R.L., 2,3,7,8-tetrachlorodibenzo-p-dioxin inhibits zebrafish caudal fin regeneration (2003) Toxicological Sciences: An Official Journal of the Society of Toxicology, 76 (1), pp. 151-161. , http://dx.doi.org/10.1093/toxsci/kfg205, PMid:12915709