Nitric oxide as a regulator in preimplantation embryo development and apoptosis

• Published in: Fertility and sterility Vol. 75; no. 6; pp. 1163 - 1171
• Main Authors: Chen, Huei-Wen, Jiang, Wen-Sheng, Tzeng, Chii-Ruey
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.06.2001; Elsevier Science
• Subjects: Animals; Animals, Outbred Strains; Apoptosis; Apoptosis - physiology; bcl-2-Associated X Protein; Biological and medical sciences; Blastocyst - physiology; c-GMP; Cyclic GMP - physiology; Early stages. Segmentation. Gastrulation. Neurulation; embryo development; Embryo, Mammalian - physiology; Embryology: invertebrates and vertebrates. Teratology; Embryonic and Fetal Development - physiology; Embryonic Development; Female; Fundamental and applied biological sciences. Psychology; Mice; nitric oxide; Nitric Oxide - physiology; p53; Pregnancy; Proto-Oncogene Proteins - metabolism; Proto-Oncogene Proteins c-bcl-2; Tumor Suppressor Protein p53 - metabolism; Up-Regulation; c-GMP; embryo development; nitric oxide; Apoptosis; p53; Embryonic development; Vertebrata; Regulation(control); Mammalia; Mouse; Nitric oxide; Embryo culture; p53 Protein; Rodentia; 3',5'-GMP; In vitro
• ISSN: 0015-0282; 1556-5653
• DOI: 10.1016/S0015-0282(01)01780-0

Objective: To investigate the mechanisms of nitric oxide (NO) in the development and apoptosis of preimplantation mouse embryos. Design: Prospective, controlled study. Setting: Medical college laboratory. Subject(s): Two-cell embryos from outbred ICR mice. Intervention(s): Hyperstimulation protocol, two-cell embryos were collected, then treated with or without an NO synthase inhibitor ( l-NAME) or an NO donor (SNP) and combined with a cGMP analogue (8-Br-cGMP) or a selective inhibitor of NO-sensitive soluble guanylyl cyclase (ODQ). Main Outcome Measure(s): The development of ICR mouse embryo from two cells to blastocyst stages in vitro. Result(s): The development of blastocyst was inhibited by l-NAME in a concentration-dependent manner (0.1–10 μM) and 0.1 μM SNP reversed this effect (80.5% of control). Annexin-V/propidium iodide and terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling techniques demonstrated that excessive NO (≥10 μM) might induce apoptosis in the mouse embryos. 8-Br-cGMP reversed the inhibitory effect of l-NAME and rescued the embryo growth. ODQ inhibited the embryo development in a dose-responsive fashion (0.1–100 μM) but had no effect in the NO-induced embryo apoptosis. P53 and Bax were found to be up-regulated during the embryo fragmentation. Conclusion(s): These results indicate that the cGMP pathway might be involved in the NO-regulated embryonic development, but not in NO-induced apoptosis, for which P53/Bax pathway might be involved.