Enzyme-linked immunosorbent assay (ELISA)
The concentrations of fms-like tyrosine kinase 1 (sFlt1) and placental
growth factor (PlGF) were determined with specific ELISA kit from
Westang Biotech Co Ltd (Shanghai, China). A commercial ELISA kit from
Cayman Chemical (catalogue #: 501320) was used to measure the
corticosterone levels in rat serum and placental tissues according to
the manufacturer’s instruction.