Nitric oxide synthase regulation during embryonic implantation
| Autor: | Valeria Rettori, E. González, Alicia Jawerbaum, Virginia Novaro, G. Canteros, M.A.F. Gimeno |
|---|---|
| Rok vydání: | 1997 |
| Předmět: |
medicine.medical_specialty
Time Factors medicine.drug_class Uterus Reproductive technology Biology Nitric Oxide Nitric oxide chemistry.chemical_compound Endocrinology Pregnancy Internal medicine Genetics medicine Animals Embryo Implantation Enzyme Inhibitors Rats Wistar Molecular Biology Embryogenesis Estrogen Antagonists Embryo Embryo culture Receptor antagonist Rats Nitric oxide synthase Isoenzymes Tamoxifen medicine.anatomical_structure NG-Nitroarginine Methyl Ester Reproductive Medicine chemistry biology.protein Animal Science and Zoology Calcium Female Nitric Oxide Synthase Developmental Biology Biotechnology |
| Zdroj: | Reproduction, fertility, and development. 9(5) |
| ISSN: | 1031-3613 |
| Popis: | It has previously been demonstrated that uterine nitric oxide synthase (NOS) activity increases before embryonic implantation in rats. The aim of the present work was to investigate the regulation and the physiological relevance of the nitric oxide (NO) system in ovoimplantation. The increase in NOS activity in early pregnancy was found to be independent of the presence of embryos in the uterus. Whereas the Ca2+-dependent isoform of NOS increased gradually in the preimplantation days, the Ca2+-independent isoform increased just at the beginning of implantation (Day 5, 1800 hours); then the activity of both isoforms declined. Oestradiol, whose concentration peaks before implantation, might be regulating NOS activity in the uterus, since treatment of rats with tamoxifen, a receptor antagonist, reduces the activity of both isoforms to preimplantation levels. Intraluminal injections of L-NAME (0·5 mg kg-1), a competitive inhibitor of NOS, reduced by 50% the number of implanted embryos; this suggests that the NO system plays a role during implantation. The data suggest that oestradiol might be a modulator of NOS activity during nidation and that NO production is necessary to achieve a successful embryo implantation. |
| Databáze: | OpenAIRE |
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