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Title:Follicle stimulating hormone and steroidogenesis in ovarian granulosa cells during aging in the domestic hen
Author(s):Palmer, Stephen Sunderland
Doctoral Committee Chair(s):Bahr, Janice M.
Department / Program:Animal Sciences
Discipline:Animal Sciences
Degree Granting Institution:University of Illinois at Urbana-Champaign
Subject(s):Biology, General
Biology, Animal Physiology
Agriculture, Animal Culture and Nutrition
Abstract:There is a decreased rate of follicular maturation with age in the domestic hen. The time required for follicular growth increases, while the number of growing follicles decreases. The causes for this physiological change with age are not defined. Perhaps there are changes with age in the responsiveness of ovarian follicles to gonadotropins.
The goal of this thesis was to determine if the responsiveness of the granulosa cells from the preovulatory follicles of the hen to FSH changes with age. The specific aims were to determine in granulosa layers of preovulatory follicles from young and old hens: (1) number of FSH receptors and progesterone (P$\sb4$) production in response to FSH; (2) amount of P$\sb{450}$ cholesterol side chain cleavage enzyme (P$\sb{450}$scc); and (3) effect of subcutaneous injections of FSH for 5 days on the pattern of follicular growth, number of FSH receptors and amount of P$\sb{450}$scc enzyme.
Granulosa cells from the 4 largest follicles of old hens compared to cells from young hens had more FSH receptors and produced more P$\sb4$ in the presence of FSH. Production of pregnenolone (P$\sb5$) and P$\sb4$ by granulosa cells in response to 8-bromo-cAMP did not differ with age. However, granulosa cells from the follicles of young hens compared to old hens had a greater amount of P$\sb{450}$scc enzyme. Exogenous FSH treatment caused a dose dependent increase in serum estradiol concentrations, yolk formation, and number of normal small follicles in the ovary. Granulosa layers from FSH treated hens compared to layers from saline injected hens had more P$\sb{450}$scc enzyme as detected by Western blots.
Follicles from old hens compared to follicles from young hens were less mature because they remained longer in an FSH dominated phase of follicular growth. The exogenous FSH treatment of old hens may have increased the rate of follicular growth and maturation because the endogenous secretion of FSH in old hens was inappropriate.
Issue Date:1989
Rights Information:Copyright 1989 Palmer, Stephen Sunderland
Date Available in IDEALS:2011-05-07
Identifier in Online Catalog:AAI9010977
OCLC Identifier:(UMI)AAI9010977

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