Ontogenia da hematopoese e da matriz extracelular em fígado fetal humano

Abstract

The liver acts as the host organ for hematopoiesis during embryogenesis. The composition and structural organization of cells and extracellular matrix are decisive for the development of hematopoietic tissue and consequent functional maturity of the liver. The objectives of this work were to analyze the structural changes and extracellular matrix components during the embryonic development of the liver, as well as to identify areas of hematopoiesis. The sample consisted of fifteen livers of male human fetuses in gestational periods of 3, 6 and 9 months. In the microscopic analysis, areas of hematopoiesis were evidenced near the connective capsule and in the sinusoidal spaces in all samples. Additionally, the structural organization type alveolar or lacunar was observed in the three gestational periods analyzed. Greater concentration of door- spaces was visualized in the central region of the organ. In the extracellular matrix was observed a higher concentration of collagen fibers around the vessels of the portal spaces, in a concentric arrangement. The collagen fiber deposition and birefringence varied in intensity between the three gestation periods, on an ascending scale. Therefore, the structural changes of cells and extracellular matrix found in the fetal hepatic parenchyma are compatible with the progression of its functional maturation.