Increase in the relative level of type V collagen in the placentae of patients with pre-eclampsia.

To obtain some insight into the extracellular matrix in the human placenta, we investigated the composition of collagens purified from the placentae of patients with pre-eclampsia and compared it with normal placentae. Collagen was extracted from the placentae of both normal and pre-eclampsia pregnancies during the third trimester. The relative amounts of various collagens were evaluated by sodium dodecyl sulphate-polyacrylamide gel electrophoresis. The ratio of the intensity of the band corresponding to the alpha 1 (III) chain with that of the alpha 1 (I) chain in placentae of pre-eclampsia was significantly lower than in normal placentae (P < 0.05). In contrast, the ratio of the intensity of the band corresponding to the alpha 1 (V) chain with that of the alpha 1 (I) chain in placentae of pre-eclampsia was significantly higher than in normal placentae (P < 0.05). The results suggest that an increased level of type V collagen relative to type I collagen in the placentae of pre-eclampsia might be closely associated with the disturbance to trophoblastic cell functions and the supply of nutrients to the developing fetus necessary for the maintenance of pregnancy.