[Study on relationship between serum cholylglycine and placental apoptosis in patients with intrahepatic cholestasis of pregnancy].

Objective: To explore the possible mechanism of placental dysfunction in patients with intrahepatic cholestasis of pregnancy (ICP).

Methods: Serum level of cholylglycine (CG) in 30 cases with ICP (ICP group) and 27 normal pregnant women (control group) was examined by radio-immunoassay before delivery. bax and bcl-2 level in placenta was detected by immunohistochemistry method.

Results: (1) Serum CG level in ICP group was (51.8 +/- 5.9) micro mol/L, and in control group it was (9.4 +/- 5.6) micro mol/L. The difference between the two groups was significant (P < 0.05). (2) bax expression level in syncytiotrophoblast of ICP group was: 2(-), 9(+), 11 (++), 8(+++), and bcl-2 expression level was: 12(+), 12(++), 6(+++); bax expression level in control group was: 9 (-), 13(+), 4(++), 1(+++) and bcl-2 expression level was: 3(+), 4(++), 20(+++). bax expression level in syncytiotrophoblast of ICP group was higher than that of the control (P < 0.0005), and bcl-2 expression level was lower than in the control (P < 0.0005), both significantly. A significant positive correlation between CG level and bax expression level and a negative correlation between CG and bcl-2 were found in ICP group (P < 0.005, P < 0.005).

Conclusion: One of the possible mechanisms involved in placental dysfunction of ICP is overexpression of bax in syncytiotrophoblast caused by high concentrations of bile acid, leading to increased apoptosis.