Please use this identifier to cite or link to this item: http://hdl.handle.net/1843/31069
Type: Tese
Title: Ação da pentoxifilina na vitalidade e no reparo tecidual dos retalhos cutaneos em ratos, administrada via subcutânea
Other Titles: Action of pentoxifylline on the vitality and tissue repair of cutaneous flaps in rats, administered by subcutaneous route
Authors: Stephanie Luzia da Costa Pedretti
First Advisor: Tarcizo Afonso Nunes
First Co-advisor: Cicero de Lima Rena
metadata.dc.contributor.advisor-co2: http://lattes.cnpq.br/3681448977451669
First Referee: Tarcizo Afonso Nunes
Second Referee: Armando Chiari Júnior
Third Referee: José Carlos Ribeiro Resende Alves
metadata.dc.contributor.referee4: Vera Maria Peters
metadata.dc.contributor.referee5: Rui Lopes Filho
Abstract: Introdução: o retalho cutâneo é considerado importante recurso cirúrgico para a reconstrução de perdas teciduais, porém pode apresentar complicações como isquemia e necrose. Objetivos: verificar a ação da pentoxifilina na vitalidade e no reparo tecidual dos retalhos cutâneos em ratos, administrada via subcutânea, na dose de 100 mg/kg. Identificar elementos histológicos, como número de vasos, reepitelização, densidade do colágeno e as dosagens de VEGF e TGF-β1. Método: foram utilizados 32 ratos da linhagem Wistar (Rattus Norvegicus albinus), distribuídos em quatro grupos, com oito animais cada, denominados CT, P1, P3, P5. Foi confeccionado retalho cutâneo de Mcfarlane modificado, pedículo caudal. O grupo CT recebeu gaze embebida com solução salina no leito do retalho. Foi administrada pentoxifilina nos grupos P1, P3 e P5, via subcutânea, no peroperatório até o 5º dia de pós-operatório. Foram aferidas as variáveis macroscópicas: dimensão total do retalho, tecido com necrose e viável. Realizou-se a exérese do retalho para análises histológicas e dosagens bioquímicas de VEGF e TGF- β1. Os animais foram submetidos à eutanásia no 10º dia do pós-operatório. Análises morfométricas quantificaram número de vasos, espessura do epitélio e densidade do colágeno. Resultados: A análise macroscópica do retalho cutâneo dos ratos mostrou que o valor da média da dimensão do tecido com necrose no grupo CT: 35,85mm (±1,95) e no grupo P5: 22,73mm (±0,87), p< 0,0001. A dimensão do tecido viável no grupo CT: 39,2mm (±1,62) e grupo P5: 45,85mm (±0,8074), p=0,0164. O número de vasos/campo aumentou nos três segmentos do retalho cutâneo e, no segmento distal do retalho dos grupos, CT: 21 (±3,4) e P5: 40 (±5,0), p=0,0174. A espessura do epitélio aumentou no segmento distal dos grupos, CT: 9µm (±0,5) e P5:15µm (±1,1), p<0,0001. A densidade do colágeno reduziu em todos os segmentos do retalho cutâneo dos grupos tratados. No segmento distal dos grupos CT: 138000µm2 (±3330), P5: 34430µm2 (±5321), p< 0,0001. Os níveis do VEGF nas amostras de pele do grupo CT: 246,8pg/mg (± 25,8), P5: 471,1pg/mg (±33,8), p< 0,0001, e no soro do grupo CT: 145,2pg/mg (± 5,1), P5: 223,9pg/mg (± 25,2), p=0,005. Os níveis do TGF-β1 nas amostras de pele do grupo CT:162,1ρg/mg (± 22,9), P5:46,4ρg/mg (± 17,20), p=0,018, e no soro do grupo CT: 313,9ρg/mg (± 28,5), P5:191,3ρg/mg (± 15,9), p=0,0063. Conclusões: A pentoxifilina, administrada via subcutânea, aumentou a vitalidade e o reparo tecidual dos retalhos cutâneos nos grupos de ratos tratados por maior número de dias. Houve aumento do número de vasos, VEGF e espessura do epitélio. Evidente diminuição da densidade do colágeno e TGF-β1.
Abstract: Introduction: the skin flaps play a very important role of the plastic surgery for the reconstruction of tissue loss, but may present complications such as ischemia and necrosis. Objectives: To verify the action of pentoxifylline, administered by subcutaneous route, at the dose of 100 mg / kg, in the vitality and tissue repair in cutaneous flaps of rats. To identify histological elements, such as number of vessels, ephithelium thickness, density of collagen and dosages of VEGF and TGF-β-1. Method: 32 Wistar rats (Rattus Norvegicus albinus), distributed in four groups named CT, P1, P3, P5, with eight animals each, were used. The modified Mcfarlane skin flap, caudal pedicle was performed. In the CT group the flap received gauze soaked with saline on the flap bed. Pentoxifylline was administered, by subcutaneous route, in the P1, P3, P5 groups, in the perioperative until the 5th postoperative day. Macroscopic variables were measured: total flap size, tissue with necrosis and tissue viability. The excision of the flap was performed for histological analysis and biochemical measurements of VEGF and TGF-β1. The animals were submitted to euthanasia on the 10th day. Morphometric analyzes quantified: number of vessels, epithelium thickness and collagen density. Results: The macroscopic analysis of the rat skin flap showed that the mean tissue size with necrosis in the CT group was 35.85 mm (± 1.95) and in the P5 group: 22.73 mm (± 0.87), p <0.0001. The size of the viable tissue in the groups, CT: 39.2mm (± 1.62) and P5: 45.85mm (± 0.8074), p = 0.0164. The morphometric analysis showed that the number of vessels / field increased in the three segments of the skin flap with significant diferences, in the distal segment of the flapin groups, CT : 21 (± 3.4) and P5: 40 (± 5.0), p = 0.0174. The epithelium thickness of the increased in the three segments of the skin. In the distal segment, CT group: 9μm (± 0.5), P5 group: 15μm (± 1.1), p <0.0001. The collagen density decreased in all segments of the cutaneous flap in the treated groups. In the distal segment, CT group: 138000μm2 (± 3330), P5 group: 34430μm2 (± 5321), p <0,0001. The levels of VEGF in the skin samples of the CT group: 246.8pg / mg (± 25.8), P5 group: 471.1pg / mg (± 33.8), p <0.0001. In the sérum, CT group: 145.2pg / mg (± 5.1), P5 group: 223.9pg / mg (± 25.2), p = 0.005. The levels of TGF-β1 in the skin samples of the CT group: 162.1 pg / mg (± 22.9), P5 group: 46.4 pg / mg (± 17.20), p = 0.018. In the sérum, group CT: 313.9 pg / mg (± 28.5), P5 group: 191.3 pg / mg (± 15.9), p = 0.0063. Conclusion: Pentoxifylline administered by subcutaneous route, increased vitality and repair of cutaneous flaps in the groups of rats treated for a greater number of days. There was an increase a number of vessels VEGF, and epithelial thickness. Evident decreased collagen density and TGF-β1.
Subject: Cicatrização
Retalhos Cirúrgicos
Pentoxifilina
Sobrevivência de Tecidos
Ratos
language: por
metadata.dc.publisher.country: Brasil
Publisher: Universidade Federal de Minas Gerais
Publisher Initials: UFMG
metadata.dc.publisher.department: MEDICINA - FACULDADE DE MEDICINA
metadata.dc.publisher.program: Programa de Pós-Graduação em Ciências Aplicadas à Cirurgia e à Oftalmologia
Rights: Acesso Aberto
URI: http://hdl.handle.net/1843/31069
Issue Date: 1-Jul-2019
Appears in Collections:Teses de Doutorado

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