Secretion of the vasoactive peptides, endothelin, and parathyroid hormone-related peptide, by decidual explants from pregnancies complicated by intrauterine growth restriction.

OBJECTIVE

To determine whether in vitro secretion of two vasoactive peptides, endothelin and parathyroid hormone-related peptide (PTHrP), is different in decidua from pregnancies complicated by intrauterine growth restriction (IUGR) than in normal pregnancies.

METHODS

In ten IUGR and nine gestational age-matched control pregnancies, decidua was collected at delivery and explants cultured for 24 hours. Endothelin and PTHrP concentrations in the conditioned medium were determined. Lactate dehydrogenase release into the medium was measured at 4 and 24 hours in a separate group of four IUGR and three control decidua.

RESULTS

Endothelin and PTHrP secretion by the decidua of the IUGR pregnancies were markedly lower than those in controls (endothelin 51 +/- 11 versus 105 +/- 16 pg/100 mg tissue/24 hours, P = .01; PTHrP 164 +/- 17 versus 641 +/- 209 ng/100 mg tissue/24 hours, P = .02). Lactate dehydrogenase release into the medium was not different between the IUGR and control decidua.

CONCLUSIONS

Based on the known effects of endothelin and PTHrP on vascular smooth muscle, it was originally anticipated that more endothelin and less PTHrP would be secreted by the IUGR decidua than the control. The finding that both peptides decreased could not be explained by route of delivery or global tissue dysfunction. Investigation of potential mediators of decidual ET and PTHrP will be necessary to determine why these hormones are both decreased in pregnancies complicated by IUGR.