Problem: 11beta-Hydroxysteroid dehydrogenase (11beta-HSD) plays an important role in regulating active glucocorticoid reaching the fetus. In normal pregnancy, placental 11beta-HSD functions primarily in oxidative direction. Placental tissue of patients with pregnancies complicated by pre-eclampsia exhibit significantly lower type 1 and 2 11beta-HSD activities and significantly high cortisol level in cord blood suggesting fetal exposure to higher level of active glucocorticoids. The activity of 11beta-HSD in gestational trophoblastic disease has not been determined. The objective of this study was to assess 11beta-HSD activity in tissue from normal second trimester and pregnancies complicated by hydatidiform mole.
Method of study: Normal placental tissues were obtained from patients undergoing termination of pregnancy, and from patients undergoing uterine evacuation for hydatidiform mole. Both nicotinamide adenine dinucleotide (NAD)- and nicotinamide adenine dinucleotide phosphate (NADP)-dependent activities were assayed in central villous tissue. Comparison of groups was performed using Student's t-test. A P-value of 0.05 was considered significant. Data are presented as mean +/- S.D.
Results: Tissue obtained from five patients with pathology-proven hydatidiform mole demonstrated significantly lower 11beta-HSD activities compared with placental tissue obtained from normal pregnancies. The mean NAD-dependent 11beta-HSD activity in normal placentas was 386 +/- 109 pmol/min/g placenta and in hydatidiform mole was 74 +/- 54 pmol/min/g placenta (P < 0.01). The mean NADP-dependent 11beta-HSD activity in normal placentas was 370 +/- 120 pmol/min/g placenta and in trophoblastic disease was 68 +/- 69 pmol/min/g placenta (P < 0.01).
Conclusion: Our data indicate significant impairment in the ability of hydatidiform mole tissue to inactivate glucocorticoids.