title: Thyroxine treatment stimulated ovarian follicular angiogenesis in immature hypothyroid rats.
abstract: The development of mature ovarian follicles is greatly dependent on healthy thecal angiogenesis. Recent experimental evidence showed that thyroxine (T4) treatment promoted ovarian follicle development in immature hypothyroid (rdw) rats. However, an involvement of thyroid hormone in ovarian follicular angiogenesis has not yet been demonstrated. By morphological and molecular approaches, the present studies demonstrated that antral follicles in untreated, T4- or equine chorionic gonadotropin (eCG)-treated rdw rats were mainly small and/or atretic, and presented a poorly developed thecal microvasculature with ultrastructural evidence of diffuse quiescent or degenerative thin capillaries. However, T4 together with eCG increased the number of large antral and mature follicles with numerous activated capillaries and ultra-structural evidence of rich and diffuse angiogenesis in the theca layer. While T4 alone significantly increased mRNA expression of vascular endothelial growth factor (VEGF) and tumor necrosis factor alpha (TNFalpha), it decreased that of fetal liver kinase compared with those in the untreated group. Combined treatment of T4 and eCG markedly increased mRNA abundance of not only VEGF and TNFalpha, but also basic fibroblast growth factor. These data suggest that T4 may promote ovarian follicular angiogenesis in rdw rats by up-regulating mRNA expression of major angiogenic factors.
authors.affiliation: Laboratory of Animal Reproduction, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan. jjiang@ohri.ca
authors.forename: Jin-Yi
authors.initials: JY
authors.lastname: Jiang
authors.forename: Kanako
authors.initials: K
authors.lastname: Miyabayashi
authors.forename: Stefania A
authors.initials: SA
authors.lastname: Nottola
authors.forename: Motoaki
authors.initials: M
authors.lastname: Umezu
authors.forename: Sandra
authors.initials: S
authors.lastname: Cecconi
authors.forename: Eimei
authors.initials: E
authors.lastname: Sato
authors.forename: Guido
authors.initials: G
authors.lastname: Macchiarelli
mesh_terms: D042501:Angiogenic Proteins / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D006063:Chorionic Gonadotropin / Q000494:pharmacology*; D016319:Corrosion Casting; D004195:Disease Models, Animal; D005260:Female; D016222:Fibroblast Growth Factor 2 / Q000378:metabolism; D007037:Hypothyroidism / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D008833:Microcirculation / Q000187:drug effects; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D018919:Neovascularization, Physiologic / Q000187:drug effects*; D006080:Ovarian Follicle / Q000098:blood supply*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013974:Thyroxine / Q000494:pharmacology*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D015854:Up-Regulation; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
chemical_list: D042501:Angiogenic Proteins; D006063:Chorionic Gonadotropin; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D042461:Vascular Endothelial Growth Factor A; C467498:vascular endothelial growth factor A, rat; D016222:Fibroblast Growth Factor 2; D013974:Thyroxine