Tissue viability of human placental explants in normoxic and hypoxic culture

Park, Se Na; Lee, Yu Sun; Shim, In Suk; Lee, Soo Yoon; Park, Mi Hye; Kim, Seung Cheol; Park, Soo Yun; Chun, Sun Hee

Abstract

OBJECTIVE
In vitro study systems for research of placental hypoxia are needed, among which human placental villous explant culture technique under experimentally variable condition is commonly used. So we performed this study to assess the viability of placental villous explant in normoxic and hypoxic culture that can provide validity for that system. METHOD: Placental villous explant tissues obtained from 9 cases of normal term pregnancies were incubated in normoxic (20% O2) and hypoxic (2~5% O2) condition for 72 hours. The viability of tissue was evaluated morphologically by microscopic examination and biochemically by LDH assay at variable time interval (0, 6, 12, 24, 48, 72 hours). The apoptosis of the tissue was assessed by TUNEL assay. RESULT: By light microscope, all of H&E stained placental explant tissue sections in normoxic and hypoxic culture showed intact villous integrities without definitive syncytial sloughing and fibrinoid necrosis as time elapsed. Tissue viability of LDH assay during 6, 24, 48, 72 hours of placental villous explants showed over all 52.3~67.6% and didn't show statistically significant difference between normoxic and hypoxic culture. Tissue viability in both groups maintained 61.2~67.6% for the first 24 hours and eventually decreased with time. TUNEL assay showed over all negative findings in normoxic and hypoxic culture at different time periods.
CONCLUSION
In vitro human placental explant culture system can be a useful and feasible technique for research of placental hypoxia which is related to development of obstetrical complications such as preeclampsia, intrauterine fetal growth restriction and preterm labor and so on. But our in vitro placental explant system needs some modification in culture condition and technique for maximizing viability of the tissue.