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Unformatted text preview: Lecture 30 - Ovarian Senescence, Menopause & Hormone Therapy The age of menopause has not changed (genetically determined)- Problem! we are living longer and they spend half of their life in menopause (unfortunately there has been some negative connotations)- Also more women are dying of heart disease than men! Primordial follicles- Important for the follicles growing and then follicles are recruited and ovulation- Thus, without primordial follicles there can be no dominant follicles , no ovulations , and no menstrual cycles e.g., menopause.- The number of primordial follicles (Ovary Reserve; formed in the fetus) declines with age reaching ~1,000 at ~50 years of age- Ovarian reserve can be measured with FSH levels; you can also assess the ovarian ageing by the number of antral follicles o Antral follicles count goes down which corresponds to the number of follicles (less follicles as you age) Recruitment:- Recruitment is the process by which an arrested primordial follicle is activated to begin growing i.e., o The entry of a primordial follicle into the pool of growing follicles. o This process leads to the decrease in primordial follicles- Mechanism poorly understood o Recruitment is controlled by local ovarian growth factors via autocrine/paracrine mechanisms. o Recruitment can be stimulated by high levels of FSH o Inhibin A and B are products of the corpus luteum and Graafian follicles, respectively. Inhibin A goes during ovulation Inhibin B produced by Graafian follciles increase during the follicular phase suppresses FSH o All Graafian follicles (healthy and atretic) secrete Inhibin B during the follicular phase . Consequently, plasma Inhibin B levels in women are determined by the total number of Graafian follicles present in the ovaries and decrease with age- The age related rise in FSH o Less primordial follicles (less eggs) less inhibin B less FSH suppression INC in FSH Consequences of ovarian aging 1. An age-related decline in female fertility o At age 37 the rate of decline of OR is greater...
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- Spring '11
- hormone therapy, primordial follicles, low estrogen