title: Evidence that the dominant follicle of the first wave is more active than that of the second wave in terms of its growth rate, blood flow supply and steroidogenic capacity in cows.
abstract: To clarify the different characteristics of the dominant follicle (DF), the DF in first ovarian follicular wave (DF-1) after spontaneous ovulation and DF in second follicular wave (DF-2) and after induced ovulation of the first-wave DF by GnRH were examined in non-lactating Holstein cows. Follicular maturation of DF-1 and DF-2 were induced by PGF2α and GnRH treatment on Day 6 and 8 (Day 0=Day of follicular wave emergence), respectively. Follicular growth and blood flow (BF) in the follicular wall of DF-1 and DF-2 were examined. To analyze sex steroids in follicular fluid (FF) and amount of mRNA in granulosa cells, DF-1 and DF-2 were aspirated on Day 8 or 9 in different estrous cycle. Diameter in DF-1 was larger than DF-2 on Day 8 and 9. From Day 8 to 9, BF area (BFA) and percentage of the follicular wall with BF, which represents the degree of distribution of BF, increased in DF-1 but not in DF-2. BFA per length of follicle circumference with BF, which represents the thickness of BF, was not different between DF-1 and DF-2. Concentrations of 17β-estradiol (E2) in plasma, E2 and androstendione in FF and amounts of LH receptor mRNA were greater in the DF-1 on Day 8. Gene expression for steroidogenesis, prostaglandin synthesis and angiogenesis did not differ between DF-1 and DF-2. These results indicated that DF-1 were more active than DF-2 in growth, BF supply and steroidogenesis. The greater BFA observed in the DF-1 may be derived from as a result of the greater vascularity in the follicular wall.
authors: The United Graduate School of Veterinary Sciences, Gifu University, Yanagido, Gifu 501-1193, Japan; Department of Clinical Veterinary Science, Obihiro University of Agriculture and Veterinary Medicine, Inada, Obihiro 080-8555, Japan.
authors: Ryotaro
authors: R
authors: Miura
authors: Department of Clinical Veterinary Science, Obihiro University of Agriculture and Veterinary Medicine, Inada, Obihiro 080-8555, Japan.
authors: Shingo
authors: S
authors: Haneda
authors: The United Graduate School of Veterinary Sciences, Gifu University, Yanagido, Gifu 501-1193, Japan; Department of Clinical Veterinary Science, Obihiro University of Agriculture and Veterinary Medicine, Inada, Obihiro 080-8555, Japan.
authors: Hsu-Hsun
authors: HH
authors: Lee
authors: Graduate School of Animal and Food Hygiene, Obihiro University of Agriculture and Veterinary Medicine, Inada, Obihiro 080-8555, Japan.
authors: Akio
authors: A
authors: Miyamoto
authors: Graduate School of Animal and Food Hygiene, Obihiro University of Agriculture and Veterinary Medicine, Inada, Obihiro 080-8555, Japan.
authors: Takashi
authors: T
authors: Shimizu
authors: Department of Clinical Veterinary Science, Obihiro University of Agriculture and Veterinary Medicine, Inada, Obihiro 080-8555, Japan.
authors: Kazuro
authors: K
authors: Miyahara
authors: Department of Clinical Veterinary Science, Obihiro University of Agriculture and Veterinary Medicine, Inada, Obihiro 080-8555, Japan.
authors: Yoh-Ichi
authors: Y
authors: Miyake
authors: Department of Clinical Veterinary Science, Obihiro University of Agriculture and Veterinary Medicine, Inada, Obihiro 080-8555, Japan. Electronic address: mmatsui@obihiro.ac.jp.
authors: Motozumi
authors: M
authors: Matsui
mesh_terms: D000818:Animals; D002417:Cattle / Q000502:physiology*; D004958:Estradiol / Q000097:blood*; D005260:Female; D006080:Ovarian Follicle / Q000098:blood supply / Q000502:physiology*; D010060:Ovulation / Q000502:physiology*; D011374:Progesterone / Q000097:blood*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
chemical_list: D012333:RNA, Messenger; D011374:Progesterone; D004958:Estradiol
keywords: Blood flow; Cow; Follicular growth; Follicular wave; Granulosa cells