Increase in the relative level of type V collagen during development and ageing of the placenta.

AIM To obtain some insight into the extracellular matrix in the placenta, changes in the composition of collagens during placental development were investigated. METHODS Collagen was extracted from placentas (group 1, 25-30 weeks, n = 21; group 2, 31-36 weeks, n = 32; and group 3, 37-41 weeks of gestation, n = 40) and the relative concentrations of various collagens were evaluated by SDS-PAGE. RESULTS The ratio of the intensity of the alpha 1 (III) band to that of alpha 1 (I) chain collagen in group 3 placentas were lower than those in group 1 placentas. In contrast, the ratio of the intensity of the alpha 1 (V) band to that of alpha 1 (I) chain collagen in group 3 placentas were higher than those in group 1 and group 2 placentas. CONCLUSIONS These results suggest that type V collagen might play an important role in the function of the placenta and that an increased relative concentration of type V collagen might be closely associated with the development and ageing of the placenta.