Production of human mast cell chymase in human myometrium and placenta in cases of normal pregnancy and preeclampsia.

OBJECTIVE

To investigate whether the human mast cell chymase-endothelin-1(1-31) system was present in human myometrium, chorion and umbilical cord in normal pregnancy.

METHODS

Myometrium, placenta and umbilical cord were obtained from five normal pregnant women and 10 with preeclampsia. Each tissue was stained with antibodies against hMC and ET-1(1-31).

RESULTS

Routine cells were located mainly around vessels. The number of hMC-positive cells and production of ET-1(1-31) were significantly higher in myometrium from patients with severe preeclampsia compared to those from normal pregnant women. In contrast, their numbers were significantly lower in placenta and umbilical cord in patients with severe preeclampsia.

CONCLUSIONS

These results suggest that the hMC-ET-1(1-31) system is active in normal pregnancy. Overproduction of hMC and ET-1(1-31) in the myometrium may be involved in the pathogenesis of severe preeclampsia, and in such cases some defense mechanism may operate in the fetus to cope with the pathological effect of the hMC-ET-1(1-31) system.