Nitric oxide inhibits development of embryos and implantation in mice

Abstract

The objectives of this study were to evaluate the effects of a nitric oxide (NO) donor on embryo development in vitro and on implantation of embryos in vivo in mice. Mouse embryos (2-cell) were incubated in media containing different concentrations of diethylenetriamine/NO (DETA/NO), a nitric oxide donor, and development was monitored daily for 4 days. Specificity of NO effects was assessed by using DETA without NO or 48 h preincubated DETA/NO. In in-vivo studies, mated mice were continuously infused, subcutaneously, with various concentrations of DETA/NO or DETA through mini-osmotic pumps (from day 1 of pregnancy), and implantations in the uterus were assessed on day 6. None of the embryos progressed beyond 4-cell stage when exposed to 0.1 or 1.0 mM DETA/NO compared with 94.5% of control embryos that developed beyond the morula stage by day 4. Embryo development was unaffected by lower (0.001 and 0.01 mM) concentrations of DETA/NO, 48 h preincubated DETA/NO, or DETA only. Infusion of DETA/NO to mice caused inhibition of embryo implantation in a dose-dependent manner. No implantation sites were observed in mice infused with a daily dose of 20 micromol DETA/NO rate, compared with an implantation rate of 81.8% in control or DETA-treated mice. This study demonstrates for the first time that higher concentrations of NO inhibit both embryo development in vitro and implantation in vivo in mice.

Protective effects of baicalin on lipopolysaccharide (LPS)-induced implantation failure and the uterine endometrium in mice

“…NO is also important in early embryonic survival. However, excessive NO values from exogenous NO donors were found to be harmful to preimplanting and implanting mouse embryos (Barroso et al, 1998). In our study, the NO productions in the serum, uterus and endometrial cells were also increased significantly by LPS.…”

Nitric oxide modulates murine yolk sac vasculogenesis and rescues glucose induced vasculopathy

“…The stage specific defects induced by NO depletion underscores the influence of the tissue micro-environment on NO-mediated actions during vascular development. These differences in susceptibility may be the result of developmental stage specific sensitivity to environmental conditions (Barroso et al, 1998;Sengoku et al, 2001). The observed sensitivity of primitive streak conceptuses to changes in NO concentration is currently unexplained; we speculate that differentiation and migratory events that occur in the splanchnic mesoderm specifically at this stage may be affected, while in late head fold stage embryos these events have been completed.…”

“…Previous studies have shown that high concentrations of NO donor (0.1 and 1 mM DETA/NO) in vivo impaired embryo development while lower concentrations (1 and 10 µM) did not cause developmental abnormalities (Barroso et al, 1998;Sengoku et al, 2001). Therefore, we supplemented low doses of a slow, steady release NO donor (NOC-18) to the culture media and assessed the tolerance of the yolk sac to exogenous NO (20 µM) during vasculogenesis.…”

“…Moreover, in vitro and in vivo studies showed that administration of either NOS inhibitors or NO donors hinders development of preimplantation embryos (i.e. expansion to blastocyst stage), which revealed the importance of maintaining appropriate levels of NO during preimplantation embryogenesis (Barroso et al, 1998;Biswas et al, 1998;Gouge et al, 1998;Sengoku et al, 2001).…”

Effect of Vaginal Sildenafil on in Vitro Fertilization Success Rates in Women With Previous Failed in Vitro Fertilization Attempts

“…Although higher concentrations of NO could result in better blood flow in the uterine, based on previous studies conducted on mice, it could also inhibit both embryo development in vitro and implantation in vivo [14], which is why discontinuing sildenafil administration before the date of HCG administration was proposed by Sher et al [12]. It has also been proposed that the GMP pathway might be involved in the NOregulated embryonic development, but not in NO-induced apoptosis which could lead to errors during implantation.…”