Requirement of nitric oxide for murine oocyte maturation, embryo development, and trophoblast outgrowth in vitro

Abstract

We investigated the extent to which NO participates in the developmental competence (oocyte maturation, fertilization and embryo development to blastocyst) using an in vitro culture system adding sodium nitroprusside (SNP), NO donor, and NOS inhibitor (N‐omega‐nitro‐L‐arginine methyl ester, L‐NAME). We also assessed the effects of NO/NOS system on blastocyst implantation using an in vitro trophoblast outgrowth assay. The treatment of low concentrations of SNP (10−7 M) significantly stimulated meiotic maturation to metaphase II stages in cumulus enclosed oocytes. In contrast, 10−3 and 10−5 M L‐NAME demonstrated a significant suppression in resumption of meiosis. This inhibition was reversed by the addition of SNP. No development beyond the four‐cell stage was observed by the addition of high concentration of SNP (10−3 M). Inhibition of embryo development, especially the conversion of morulae to blastocysts, was also observed in the treatment of lower doses of SNP (10−5 and 10−7 M). Similarly, inhibition of NO by NOS inhibitor resulted in the dose‐dependent inhibition of embryo development and hatching rates, but the concomitant addition of SNP with L‐NAME reversed the inhibitory effect by each SNP or L‐NAME treatment. Furthermore, low concentration of SNP (10−7 M) but not high concentration of SNP (10−3 M) significantly stimulated trophoblast outgrowth, whereas the addition of L‐NAME suppressed the spreading of blastocysts in a dose‐dependent manner. These results suggest that NO may have crucial roles in oocyte maturation and embryogenesis including the process of implantation. The observed differences in required amount of NO and the sensitivity to cytotoxicity of NO in each developmental stage embryos may also suggest that NO/NOS system is tightly regulated in developmental stage specific manner. Mol. Reprod. Dev. 58:262–268, 2001. © 2001 Wiley‐Liss, Inc.

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.…”

“…The importance of NO as a regulator of early developmental events has been established by studies that demonstrated that the oocyte and preimplantation embryo are exposed to NO, and oocyte maturation, preimplantation embryogenesis and implantation require NO (Biswas et al, 1998;Gagioti et al, 2000;Maul et al, 2003;Novaro et al, 1997;Purcell et al, 1999;Sengoku et al, 2001;Shukovski and Tsafriri, 1995;Telfer et al, 1995). Moreover, in vitro and in vivo studies showed that administration of either NOS inhibitors or NO donors hinders development of preimplantation embryos (i.e.…”

“…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).…”

Nitric oxide in follicle development and oocyte competence

“…NO is now thought to represent a vital component of the oocyte microenvironment as it plays a physiological role during oocyte maturation, fertilization, and beginning of embryo development (Jablonka-Shariff & Olson 1998, Sengoku et al 2001, Bergandi et al 2014.…”