title: Direct real-time measurement of intra-oocyte nitric oxide concentration in vivo.
abstract: Nitric oxide (NO) is reported to play significant a role in oocyte activation and maturation, implantation, and early embryonic development. Previously we have shown that NO forms an important component of the oocyte microenvironment, and functions effectively to delay oocyte aging. Thus, precise information about intra-oocyte NO concentrations [NO] will result in designing more accurate treatment plans in assisted reproduction. In this work, the direct, real-time and quantitative intra-oocyte [NO] was measured utilizing an L-shaped amperometric integrated NO-selective electrode. This method not only provides an elegant and convenient approach to real-time the measurement of NO in physiological environments, but also mimics the loss of NO caused by rapid NO diffusion combined with its reactivity in the biological milieu. This experiment suggests that the NO levels of oocytes obtained from young animals are significantly higher than those of oocytes obtained from old animals. Additionally the NO levels stay constant during the measurements; however, the intra-oocyte [NO] is reduced significantly (70-75% reduction) in response to L-NAME incubation, suggesting that NO measurements are truly NOS based rather than caused by an unknown interfering substance in our system. We believe this first demonstration of the direct quantitative measurement of [NO] in situ in an intact cellular complex should be useful in tracking real-time and rapid changes at nanomolar levels. Moreover, this finding confirms and extends our previous work showing that supplementation with NO delays the oocyte aging process.
authors.affiliation: Division of Reproductive Endocrinology and Infertility, Department of Obstetrics & Gynecology, The C. S. Mott Center for Human Growth and Development, Wayne State University, Detroit, Michigan, United States of America; Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, University of California Davis, Sacramento, California, United States of America; California IVF Fertility Center, Davis and Sacramento, California, United States of America.
authors.forename: Pravin T
authors.initials: PT
authors.lastname: Goud
authors.affiliation: California National Primate Research Center, University California Davis, Davis, California, United States of America.
authors.forename: Anuradha P
authors.initials: AP
authors.lastname: Goud
authors.affiliation: Division of Reproductive Endocrinology and Infertility, Department of Obstetrics & Gynecology, The C. S. Mott Center for Human Growth and Development, Wayne State University, Detroit, Michigan, United States of America.
authors.forename: Tohid
authors.initials: T
authors.lastname: Najafi
authors.affiliation: Division of Reproductive Endocrinology and Infertility, Department of Obstetrics & Gynecology, The C. S. Mott Center for Human Growth and Development, Wayne State University, Detroit, Michigan, United States of America.
authors.forename: Bernard
authors.initials: B
authors.lastname: Gonik
authors.affiliation: Department of Obstetrics & Gynecology, Georgia Regents University, Augusta, Georgia, United States of America.
authors.forename: Michael P
authors.initials: MP
authors.lastname: Diamond
authors.affiliation: Division of Reproductive Endocrinology and Infertility, Department of Obstetrics & Gynecology, The C. S. Mott Center for Human Growth and Development, Wayne State University, Detroit, Michigan, United States of America.
authors.forename: Ghassan M
authors.initials: GM
authors.lastname: Saed
authors.affiliation: World Precision Instruments, Sarasota, Florida, United States of America; Research Center for Bioengineering & Sensing Technology, University of Science & Technology, Beijing, P.R. China.
authors.forename: Xueji
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Division of Reproductive Endocrinology and Infertility, Department of Obstetrics & Gynecology, The C. S. Mott Center for Human Growth and Development, Wayne State University, Detroit, Michigan, United States of America; Department of Biochemistry and Molecular Biology, Wayne State University, School of Medicine, Detroit, Michigan, United States of America.
authors.forename: Husam M
authors.initials: HM
authors.lastname: Abu-Soud
mesh_terms: D000818:Animals; D002138:Calibration; D004566:Electrodes; D005260:Female; D051379:Mice; D009569:Nitric Oxide / Q000378:metabolism*; D009865:Oocytes / Q000378:metabolism*
chemical_list: D009569:Nitric Oxide