title: Expression of endothelial nitric oxide synthase in the ovine ovary throughout the estrous cycle.
abstract: This study was conducted to evaluate the expression of endothelial nitric oxide synthase (eNOS) in ovarian follicles and corpora lutea (CL) throughout the estrous cycle in sheep. Three experiments were conducted to (1) immunolocalize eNOS protein, (2) determine expression of mRNA for eNOS and its receptor guanylate cyclase 1 soluble beta3 (GUCY1B3), and (3) co-localize eNOS and vascular endothelial growth factor (VEGF) proteins in the follicles and/or CL throughout the estrous cycle. In experiment 1, ovaries were collected from ewes treated with FSH, to induce follicular growth or atresia. In experiment 2, ovaries were collected from ewes treated with FSH and hCG to induce follicular growth and ovulation. In experiment 3, ovaries were collected from superovulated ewes to generate multiple CL on days 2, 4, 10, and 15 of the estrous cycle. In experiments 1 and 2, the expression of eNOS protein was detected in the blood vessels of the theca externa and interna of healthy ovarian follicles. However, in early and advanced atretic follicles, eNOS protein expression was absent or reduced. During the immediate postovulatory period, eNOS protein expression was detected in thecal-derived cells that appeared to be invading the granulosa layer. Expression of eNOS mRNA tended to increase in granulosa cells at 12 and 24 h, and in theca cells 48 h after hCG injection. In experiment 3, eNOS protein was located in the blood vessels of the CL during the estrous cycle. Dual localization of eNOS and VEGF proteins in the CL demonstrated that both were found in the blood vessels.
authors.affiliation: Department of Animal and Range Sciences, North Dakota State University, Fargo, North Dakota 58105-5727, USA.
authors.forename: Anna T
authors.initials: AT
authors.lastname: Grazul-Bilska
authors.forename: Chainarong
authors.initials: C
authors.lastname: Navanukraw
authors.forename: Mary Lynn
authors.initials: ML
authors.lastname: Johnson
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Arnold
authors.forename: Lawrence P
authors.initials: LP
authors.lastname: Reynolds
authors.forename: Dale A
authors.initials: DA
authors.lastname: Redmer
mesh_terms: D000818:Animals; D003338:Corpus Luteum / Q000098:blood supply / Q000201:enzymology; D030762:Estrous Cycle / Q000502:physiology*; D005260:Female; D015870:Gene Expression; D006107:Granulosa Cells / Q000201:enzymology; D006162:Guanylate Cyclase / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D007091:Image Processing, Computer-Assisted; D007150:Immunohistochemistry / Q000379:methods; D052250:Nitric Oxide Synthase Type III / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D010053:Ovary / Q000201:enzymology*; D012333:RNA, Messenger / Q000032:analysis; D018160:Receptors, Cytoplasmic and Nuclear / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012756:Sheep / Q000378:metabolism*; D000071756:Soluble Guanylyl Cyclase; D013799:Theca Cells / Q000201:enzymology; D042461:Vascular Endothelial Growth Factor A / Q000032:analysis / Q000235:genetics / Q000378:metabolism
chemical_list: D012333:RNA, Messenger; D018160:Receptors, Cytoplasmic and Nuclear; D042461:Vascular Endothelial Growth Factor A; D052250:Nitric Oxide Synthase Type III; D006162:Guanylate Cyclase; D000071756:Soluble Guanylyl Cyclase