Download Male sex hormones

Male and female sex hormones
Male sex hormones
Testosterone production and spermatogenesis
Infertility and male hypogonadism
Female sex hormones
Normal menstrual cycle
Human chorionic gonadotrophin(hCG)
Effect of pregnancy on biochemical tests
Complications in pregnancy
Male sex hormones
 The male gonads are the testes.
 Testes have a double function: to produce and secrete
the male hormone, testosterone, and to produce the
spermatozoa.
 The pituitary gonadotropin LH stimulates interstitial cells
in the testis to produce testosterone and FSH promotes
spermatogenesis by the germinal cells.
 Plasma testosterone levels in normal adult males range
from 350-1200ng/dl (3.5-12 μg/d, and 30-90ng/dl in
female.
Investigation of infertility
and male hypogonadism
Female sex hormones
 The female gonad, ovary, has a double function; it not only
produces and secretes the female sex hormones, but it is the
site of production and maturation of the ova.
 One mature ovum is released approximately once every 4 or
5 weeks.
 The reproductive system of female is more complicated than
in males because of the cyclical events that take place during
the menstrual cycle and even greater changes that occurs
during pregnancy.
 2 different chemical types of steroid hormones are produced
and secreted by ovary in non-pregnant females during
pregnancy, the same hormones are produced by the ovary,
but in different proportions.
 The placenta also makes the hormones that necessary for
maintenance of pregnancy.
The hypothalamic–pituitary–
ovarian axis. Activins, inhibins
and progesterone also have a
role in regulating the cycle.
 The first group of female sex hormone, the estrogen, originate
in the ovarian follicle( and also in the placenta during
pregnancy).
 The estrogens participate in the menstrual cycle and are
essential for the development and maintenance of the
reproductive organs and secondary sex characteristics.
 The second group comprises progesterone and its metabolites
, which are formed in the corpus luteum, the body that
develops from ruptured ovarian follicle.
 Progesterone is secreted after ovulation, stimulates the uterus
to undergo changes that prepare it for implantation of the
fertilized ovum and suppresses ovulation and secretion of
pituitary LH.
 IF pregnancy occurs, the secretion of progesterone by the
corpus luteum and also by the placenta, suppresses
menstruation for the duration of the pregnancy.
Changes in plasma
concentrations of
FSH, LH and the
principal gonadal
steroids in the
normal menstrual
cycle
• Oestrogens act on several target tissues, including the
uterus, vagina and breast; progesterone mainly acts on
the uterus, and is essential for the maintenance of early
pregnancy.
• Both oestrogens and progesterone are important in the
control of the hypothalamic–pituitary–ovarian axis.
• Oestradiol may stimulate or inhibit the secretion of
gonadotrophins, depending on its concentration in
plasma; the stimulating effect of oestradiol can be
prevented by high plasma [progesterone].
• Inhibins and activins also play a role in regulating
ovarian function and they change during the cycle;
however, their measurement is not performed as part of
routine investigation. Inhibin B originates from
developing follicles
Human chorionic gonadotrophin(hCG)
 The placenta produces several proteins, including hCG
and (human) placental lactogen. It also produces large
amounts of steroid hormones and is the main source of
progesterone during pregnancy.
 The most commonly measured is hCG.
 Following synthesis, hCG is secreted into the maternal
circulation. There is a surge in maternal [hCG] in early
pregnancy, peak blood levels being reached at 12 weeks;
there after, production of hCG rapidly declines. hCG
becomes detectable in urine about 10 days after
conception, and this forms the basis of readily available
pregnancy tests.
Changes in TSH, thyroid hormones, hCG and TBG in normal pregnancy.
For TSH and thyroid hormones it is important to use gestational or
trimester related reference ranges. In some pregnancies TSH may fall
to <0.1 mU/L in the first trimester. Total T3 and FT3 follow the same
pattern as total T4 and FT4, respectively.
Effect of pregnancy on biochemical tests
 Serum prolactin, oestrogens and testosterone show a
steady increase in pregnancy .
 There are large increases in serum cortisol due to
increased serum cortisol binding globulin (CBG).
 In normal pregnancy there is an increase in the pool size of
extra-thyroidal T4 and an increase in the deiodination of
thyroid hormones from the developing placenta.
 During pregnancy, the plasma volume and GFR increase,
sometimes by as much as 50%. And decreases in, for
example, serum[sodium], [urea] and [creatinine].
 Serum triglyceride may increase as much as 3-fold in
pregnancy; serum cholesterol, LDL and HDL increase to a
lesser extent.
 In pregnancy, the placental isoenzyme of ALP is released,
and total ALP activity in serum may rise to as much as 3
times nonpregnant levels. In contrast, the expansion of
the extracellular fluid leads to a fall (∼20%) in the
activities of the transaminases and in the concentration
of bilirubin.
 During pregnancy, serum [ferritin] and serum [iron], are
decreased due to increased maternal red cell synthesis
and transfer of iron to the developing fetus.
Complications in pregnancy
 Ectopic pregnancy.
In ectopic pregnancy, serum [hCG] fails to rise at the normal
rate (approximately doubling every 2–3 days).
 Diabetes mellitus.
Women with type 1 diabetes are at greater risk from both
diabetic and obstetric complications during pregnancy. They
need for careful home glucose monitoring (4–6 times a day)
and intensive insulin regimens. Women should aim to
maintain blood glucose and HbA1c concentrations as near to
the nondiabetic range as possible without excessive risk of
hypoglycaemia.
Type 2 diabetes is less common during the reproductive
years, but its management during pregnancy should follow
the same intensive pattern.