Résumé
OBJECTIVE: To characterize the effect of IL-1 beta, on connective tissue metabolism in a human chorioamniotic membrane tissue culture (CAM). TYPE OF STUDY: Experimental, in an in vitro model. MATERIAL AND METHODS: CAM explants obtained from cesarean sections were cultured. The presence of local infection was excluded by microbiological methods. An XTT viability essay of the explants was carried out. Explants were stimulated with different doses of IL-1 beta within a 0-10 ng/mL range. After the stimulation, protein content was measured, MMP-9 production was determined by zymography, and each explant was divided in two parts: one was used for collagen measurement and the other analyzed by electronic microscopy. RESULTS: CAMs kept adequate viability and functionality. IL-1 beta stimulation produced an increase in the amount of MMP-9 expressed, as determined by the zymography method with a maximum effect 36 hours after stimulation. Collagen content decreased in a progressive manner after IL-1 beta stimulation and reached its minimum after 36 hours. The characteristic pattern of collagen fibers gradually lost its organization, and could not be observed any more after 36 hours. CONCLUSIONS: The information presented here allows us to conclude that IL-1 beta is capable of inducing an enzymatic expression affecting connective tissue, thus confirming its participation in membrane degradation processes under inflammatory conditions.