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CASE FILES: BIOCHEMISTRY
A N SW E R S TO C A SE 48: M E N O PA U SE
Summary:
A 52-year-old female presents with hot flushes, mood swings, irri-
tability, vaginal dryness and atrophy, and last menstrual period over 1 year ago.
Organ secreting follicle-stimulating hormone (FSH): Anterior
pituitary gland.
Signal stimulating FSH release: Gonadotropin releasing hormone
from the hypothalamus binds to membrane receptors of the anterior
pituitary cells, triggered phosphatidylinositol signaling to stimulate
FSH production and release.
C L IN IC A L C O R R E L A T IO N
This 52-year-old woman has symptoms of estrogen insufficiency, such as hot
flushes, mood swings, and vaginal dryness. Her last menstrual period was
1 year ago, consistent with the menopause. The etiology of the hypoestrogen
state is follicular atresia of the ovaries. Once in puberty, a woman usually has
fairly regular menstrual cycles as dictated by the estrogen and progesterone
secretion of the ovaries until about age 40 to 50 years. During a period of 2 to
4 years, some women may experience irregular menses because of irregular
ovulation until finally there are no further menses. The diagnosis of the
menopause is made by clinical criteria, although the gonadotropins, FSH, and
luteinizing hormone (LH) are usually elevated.
A PPR O A C H TO T H E M E N ST R U A L C Y C L E
O bjectives
1.
Be familiar with the hormones that control reproduction.
2.
Know about the regulation of the normal menstrual cycle.
3.
Understand the hormone changes during menopause.
D efinitions
Apoptosis: Programmed cell death that leads to the destruction of cells
leaving membrane-bound particles that are shed or taken up by
phagocytosis.
Estradiol: 17-P-Estradiol; an estrogen steroid hormone that is synthesized
in the granulose cells of the ovary and secreted in response to binding of
FSH released from the anterior pituitary.
FSH: Follicle-stimulating hormone; a polypeptide hormone that contains
a and P subunits that is synthesized in and released from the anterior
pituitary in response to binding of GnRH. When binding to receptors on
the plasma membrane of the granulose cells of the ovarian follicle, it
stimulates the synthesis and secretion of estradiol.
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