Preeclampsia-associated decrease of potential collagenolytic and gelatinolytic activities in the wall of the...

Preeclampsia is the most common pathological syndrome associated with pregnancy. It is accompanied by remodelling of the extracellular matrix of the umbilical cord. A decrease of collagen content in the umbilical cord vein was described. This decrease may result from reduced collagen biosynthesis or enhanced collagen degradation. It was decided to evaluate whether or not this phenomenon is associated with alterations in the activities of collagenolytic, gelatinolytic and non-specific proteolytic enzymes that may be involved in collagen degradation, as well as the activity of prolidase which provides proline as a substrate for collagen biosynthesis. Studies were performed on the umbilical cord veins of newborns delivered by healthy mothers and those with preeclampsia. The control vein extract, activated with trypsin, degraded reconstituted collagen fibres (64.4+/-2.9 nmol Hyp x mg(-1) protein), whereas the preeclamptic material demonstrated only a trace activity. The venous wall extract contained a latent form of gelatinase that might have been activated by trypsin and 4-aminophenylmercuric acetate. A decrease in the gelatinolytic and proteolytic activities of preeclamptic vein extract at neutral pH was found. Prolidase activity was almost 3-fold lower in the preeclamptic extract (240.6+/-29.3 nmol Pro x min(-1) x mg(-1) protein) in comparison to the control (608.2+/-63.7 nmol Pro x min(-1) x mg(-1)protein). It was concluded that the umbilical cord vein contains a latent form of gelatinase A. The decrease in prolidase activity may reduce collagen biosynthesis, resulting in a decrease of this protein in the preeclamptic umbilical cord vein.