Elevated Plasma Chymotrypsin-like Protease (Chymase) Activity in Women with Preeclampsia

Objective: Chymase, a chymotrypsin-like protease, is a non-ACE angiotensin II (Ang II) generating enzyme. We determined if maternal chymotrypsin-like protease/chymase activity was increased in women with preeclampsia (PE). Methods: Maternal plasma was extracted from venous blood of healthy nonpregnant women, women with normal and preeclamptic pregnancies. Chymotrypsin-like protease/chymase activity was measured by a colorimetric assay. Maternal vessel chymotrypsin-like protease/chymase expression was examined by immunohistochemistry. Results: Maternal plasma chymotrypsin-like protease/chymase activity was significantly higher in women with PE than in nonpregnant and normal pregnant women: 0.181 +/- 0.011 vs. 0.097 +/- 0.05 (p < 0.01) and 0.132 +/- 0.013 (p < 0.05) mu kat/mL. Chymotrypsin-like protease/chymase activity was markedly reduced 24 hours postpartum in women with PE, p < 0.05. Enhanced chymotrypsin-like protease/chymase expression was observed in vascular endothelium in women with PE compared with those in normal pregnancies. Conclusions: Elevated maternal chymotrypsin-like protease/chymase activity and enhanced protease immunostaining in the maternal vessel endothelium may constitute the exacerbated inflammatory state and account for the increased vascular Ang II sensitivity in PE.