Expression of vascular endothelial growth factor mRNA in human preimplantation embryos derived from tripronuclear zygotes

Objective: To detect the expression of vascular endothelial growth factor ( VEGF) mRNA and/or secretion of VEGF protein by human preimplantation embryo s. Design: Human preimplantation embryos not suitable for uterine transfer wer e examined for beta -actin and VEGF mRNA expression. Culture media from nor mally fertilized and developing preimplantation embryos were assessed for V EGF protein secretion. Setting: Clinics and academic research laboratories at the Departments of O bstetrics and Gynecology at the Stanford University, Pale Alto, California and the Heinrich-Heine-University, Dusseldorf, Germany. Patient(s): Couples undergoing IVF by intracytoplasmic sperm injection for various reasons. Intervention(s): Six unfertilized oocytes and 33 pathologically fertilized (tripronucleic, 3PN) preimplantation embryos were examined for VEGF mRNA ex pression, and 16 embryos were examined for VEGF protein secretion. Main Outcome Measure(s): Embryonic expression of VEGF mRNA and VEGF protein as determined by reverse transcription (RT)/nested polymerase chain reacti on (PCR) and ELISA. Result(s): VEGF mRNA and protein could not be detected in unfertilized oocy tes. However, 30/33 preimplantation embryos did express VEGF mRNA (11/12 10 -to-16-cell embryos, 3/4 morulae, 11/12 early blastocysts, 5/5 hatched blas tocysts). The VEGF protein level was below the sensitivity of the ELISA. Conclusion(s): Production of VEGF may give the embryo the ability to induce neoangiogenesis at the implantation site, thus creating an environment nec essary for its survival. (Fertil Steril(R) 2000;74:1220-6 (C) 2000 by Ameri can Society for Reproductive Medicine).