Expressão e atividade de MMP-2 e MMP-9 durante o desenvolvimento do intestino delgado de ratos

Abstract

Matrix metalloproteinases (MMPs) 2 and 9 are well studied enzymes for their roles in tissue remodeling, either under pathological conditions or during the morphogenesis process. However, regarding the development of the small intestine (ID) and its growth that begins in intrauterine life and continues after birth, there are still few reports about the role of these MMPs. Therefore, this study aimed to evaluate the expression and activity of MMP-2 and MMP-9 during intrauterine and postnatal development of rat small intestine. Intestines were collected from rats on the 15th and 18th day of intrauterine life (IU) and on the 3rd, 10th, 17th, 25th and 32nd day after birth. The samples were submitted to zymography, immunohistochemistry and histochemistry methods. The results showed that there was no activity and expression of MMP-2 and MMP-9 in the small intestine during the evaluated intrauterine life stages. In postnatal life there was no expression and activity of MMP2, but only the expression and activity of MMP-9 were detected at the times evaluated. MMP-9 was immune localized into villi goblet cells and lamina propria cells. Subsequently, cells identified as mast cells by the Masson's Tricromic method were found in regions that coincide with those where immuno-stained cells were found. Thus, it is suggested that MMP-2 and MMP-9 may have no function during the development of the small intestine at the ages evaluated at work. However, MMP-9 was detected in goblet cells and lamina propria after birth, indicating a possible immune defense-related activity during postnatal growth of the small intestine.