Influence of indomethacin on the regenerative process of the tail fin of teleost: morphometric and ultrastructural analysis

Abstract

When partially amputated or severely injured, teleost fins suffer a regenerative process called epimorphic regeneration characterised by the following stages: the formation of a multistratified epidermal layer, the disorganisation and distal migration of multipotent mesenchymal cells, the proliferation of these cells in order to form the blastema, continuous proliferation of distal blastema to facilitate the growth, and differentiation of the proximal blastema in order to restore its lost structure. The regeneration of the fin is extremely sensitive to the action of some drugs that can interfere in its structure restoration. For this reason, and also based on papers relating that indomethacin can interfere somehow in the tissue restoration of many different organisms, the aim of this work is to evaluate the possible effects of this drug in three different doses in the regeneration of the teleost fish tail fin, taking into consideration the synthesis, the disposition and organisation of lepidotrichial matrix components, the restoration of actinotrichia, as well as the fin area itself. Therefore, histochemical, ultrastructural and morphometric analysis were done and it was observed that indomethacin in doses of 20 and 30 mg.L -1 caused a delay in the regenerative process of the dermal skeleton (lepidotrichia and actinotrichia) of the tail fins. These doses could have interfered, momentarily, in the process of blastemal cell differentiation in the cells responsible for the synthesis and disposition of actinotrichia and lepidotrichia or, even interfered in the signalling necessary for the recent differentiated cells to begin synthesising the components of the dermal skeleton. Keywords: indomethacin, regeneration, fin, fish.Influência da indometacina no processo regenerativo da nadadeira caudal de teleósteo: análise morfométrica e ultraestrutural ResumoQuando parcialmente amputadas ou severamente injuriadas, as nadadeiras de teleósteos sofrem um processo de regeneração chamado de regeneração epimórfica, caracterizado pelas seguintes fases: formação de uma capa epidermal multiestratificada, desorganização e migração distal de células mesenquimais multipotentes, proliferação dessas células para formar o blastema, proliferação contínua do blastema distal para facilitar o crescimento e diferenciação do blastema proximal para restaurar as estruturas perdidas. A regeneração que a nadadeira sofre é extremamente sensível à ação de algumas drogas que podem interferir na reparação de suas estruturas. Em vista disso, e também pelo fato de que há relatos na literatura de que a indometacina pode interferir de alguma maneira na restauração tecidual de diversos organismos, o objetivo deste trabalho foi o de avaliar os possíveis efeitos desta droga, em três doses diferentes, na regeneração da nadadeira caudal de peixe teleósteo, considerando a síntese, deposição e organização dos componentes da matriz lepidotriquial, a regeneração da actinotriquia, bem como a área da nadadeira como um todo. Para isso, foram feitas análises h...

The Physical Role of Mesenchymal Cells Driven by the Actin Cytoskeleton Is Essential for the Orientation of Collagen Fibrils in Zebrafish Fins

“…Extensive molecular genetic studies on the formation and function of actinotrichia have been conducted in zebrafish. Several studies using transmission electron microscopy (TEM) have shown that actinotrichia are distributed between the basement membrane just below the basal epithelial cells and mesenchymal cells ( Wood and Thorogood, 1987 ; Böckelmann and Bechara, 2010 ). In zebrafish larva with Col1a1a and Col2a1b function inhibited using morpholino antisense oligos, actinotrichia production is inhibited and the fin fold growth is defective ( Durán et al, 2011 ).…”