Estudo da migração de neutrofilos in vitro em coelhos hepatopatas

Orientador : Jose Pedrazzoli JuniorDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências MédicasResumo: A doença hepática crônica apresenta diversas causas, sendo caracterizada por diferentes graus de inflamação e necrose hepatocelular. A hepatite crônica pode ocorrer devido a vírus, reações autoimunes, drogas ou toxinas. Utilizando-se o modelo experimental de hepatopatia em coelhos induzido por CCU, o objetivo deste estudo foi investigar uma possível relação entre alguns parâmetros relacionados ao processo inflamatório (quimiotaxia de neutrófilos e análise total e diferencial dos leucócitos) e a lesão hepática. A extensão do dano hepático produzido pelo CCU foi investigada através da análise histológica dos fígados. Nossos resultados demonstraram que o tratamento com CCL4 induziu lesão hepática nos coelhos, conforme demonstrada pela análise histológica e pela elevação dos níveis séricos das enzimas ALT e AST. A análise histológica indicou a presença de hepatite após a 2a semana e de cirrose na 6a ou 8a semana de tratamento com CCL4. A resposta quimiotática in vitro dos neutrófilos verificada uma semana após a administração da droga, mostrou aumento entre a 2a e 6a semana de tratamento. Quando verificada 24 h após a droga, a quimiotaxia apresentou elevação a partir da 2ª até a 8a semana de tratamento. Neste mesmo período observou-se também aumento no número dos neutrófilos do sangue periférico. Levando-se em conta a verificação da presença de neutrófilos no fígado dos animais com cirrose, estes resultados 24 horas após a droga, sugerem que o aumento da migração in vitro dos neutrófilos e a elevação do número dos polimorfonucleares do sangue periférico podem estar relacionados à ativação e ao recrutamento destas células inflamatórias para o fígado, onde desempenham importante função no desenvolvimento do dano hepáticoAbstract: The aim of this study was to investigate neutrophil chemotaxis during the induction of liver cirrhosis in rabbits. The study had three expérimentai arms: Group A (n=16) served as controls and received only normal rabbit chow. All animals were sacrificed at 16 weeks. Group B (n=19) was sacrificed 48 h after the chemotaxis assay, which was performed 24 h after CCL4 administration, at weeks 2, 4, 6 and 8. Group C (n=8) was followed by 16 weeks. The chemotaxis assay was performed 1 week after CCU administration. All animals were sacrificed at 16 weeks. The rabbits were treated with intragastric administration of CCU once weekly starting 14 days after addition of Phénobarbital to the drinking water (50mg/day). The CCU dose was adjusted weekly in order to obtain serun ALT and AST levels between 400 and 800 IU/I. Our results showed that increased ALT and AST levels were found in all of CCU-treated rabbits compared to the controls. In liver from animals sacrificed in 2, 4, 6 and 8 weeks of CCU treatment, hepatitis and fibrosis were already found at week two, and liver cirrhosis at week 6 and 8. Sixteen-week CCU treatment resulted in liver cirrhosis in 7 animals (87.5%). All animals with liver cirrhosis had an inflammatory infiltrate with neutrophils. Treatment with CCU did not interfered with total leukocyte count in blood from animals sacrificed in different periods, but a significant increase in polymorphonuclear cells between weeks 2 to 8 and a significant reduction in mononuclear leukocytes at week 4 were observed when compared with control animals. Neutrophil chemotaxis was also significantly increased from week 2 through week 8 compared with the control group. Animals that received CCU for 16 weeks present a significantly increased total leukocyte and polymorphonuclear number at week 10 when compared to controls. The mononuclear cell number was unchanged during the study period. A significant increase in neutrophil chemotaxis was observed from week 2 trough week 6. The presence of neutrophils in the liver of all animals with cirrhosis associated with an increase in polymorphonuclear cell chemotaxis during CCL4 administration in our experiment supports the view that this cell line has an important role in the development of toxic liver damageMestradoMestre em Farmacologi