They are adenohypophyseal hormones which mean that they are secreted from antirior pituitary
FSH follicle stimulating hormone
LH luteinizing hormone
Control of them
1. By GnRH (gonadotrophin- releasing hormone) which secrete from Hypothalamus
2.The gonads secrete inhibin & activin which selectively inhibit & activiteFSH secretion from the pituitary
LH in female
1. initiate steroidogenesis in ovarian follicle
3.maintain secratory function of corpus luteum
LH in male
1.stimulates leydig cells to produce testosterone
FSH in female
1.stimulates development of ovarian follicles
2.stimulates secretion of oestradiol
3.secration of inhibin
FSH in male
1.stimulates spermatogenesis in sertoli cells
2.production of sex hormone-binding globulin
3.secretion of inhibin
Why are they tested ?
FSH is often used in conjunction with other tests (LH, testosterone, estradiol, and progesterone) in the workup of infertility in both men and women. FSH levels are used to help determine the reason a man has a low sperm count. FSH levels are also useful in the investigation of menstrual irregularities and to aid in the diagnosis of pituitary disorders or diseases involving the ovaries or testes. In children, FSH and LH are used to diagnose delayed or precocious (early) puberty.
In women and men, FSH and LH are ordered as part of the workup of infertility and pituitary or gonadal disorders. FSH may be ordered when a woman’s menstrual cycle has stopped or become irregular, to determine if the woman has entered menopause. In children, FSH and LH may be ordered when a boy or girl does not appear to be entering puberty at an appropriate age (either too late or too soon). Irregular timing of puberty may be an indication of a more serious problem involving the hypothalamus, the pituitary gland, the gonads (ovaries or testes), or other systems. The measurement of LH and FSH may help differentiate between benign symptoms and true disease. Once it is established that symptoms are a result of true disease, further testing can be done to discern the underlying cause.
What does the test result mean? in women, FSH and LH levels can help to differentiate between primary ovarian failure (failure of the ovaries themselves) and secondary ovarian failure (failure of the ovaries due to disorders of either the pituitary or the hypothalamus). Increased levels of FSH and LH are consistent with primary ovarian failure. Some causes of primary ovarian failure are listed below.
• Failure to develop ovaries (ovarian agenesis)
• Chromosomal abnormality, such as Turner’s syndrome
• Defect in the steroid production by the ovaries, such as 17 alpha hydroxylase deficiency
Premature ovarian failure due to:
• Autoimmune disease
Chronic failure to ovulate (an ovulation) due to:
• Polycystic ovary syndrome (PCOS)
• Adrenal disease
• Thyroid disease
• Ovarian tumor
When a woman enters menopause and her ovaries stop working, FSH levels will rise.
Low levels of FSH and LH are consistent with secondary ovarian failure due to a pituitary or hypothalamic problem. Low FSH serum levels have been associated with increased risk of ovarian cancer.
In men, high FSH levels are due to primary testicular failure. This can be due to developmental defects in testicular growth or to testicular injury, as indicated below.
• Failure to develop gonads (gonadal agenesis)
• Chromosomal abnormality, such as Klinefelters syndrome
• Viral infection
• Autoimmune disease
• Germ cell tumor
Low levels are consistent with pituitary or hypothalamic disorders.
High levels of FSH and LH with the development of secondary sexual characteristics at an unusually young age are an indication of precocious puberty. This is much more common in girls than in boys. This premature development can have many different underlying causes that need to be diagnosed and treated. Some of the causes include:
• Central nervous system lesions
• Hormone-secreting tumors
• Ovarian tumors or cysts
• Testicular tumors
Normal prepubescent levels of LH and FSH in children exhibiting some signs of pubertal changes may indicate a benign form of precocious puberty with no underlying or discernable cause or may just be a normal variation of puberty.
In delayed puberty, LH and FSH levels can be normal or below what is expected for a youth within this age range. A test for LH response to GnRH may need to be performed along with other testing to diagnose the reason for the delayed puberty. Some of the causes for delayed puberty can include:
• Gonadal (ovary or testes) failure
• Hormone deficiency
• Turner’s syndrome (chromosomal abnormality in girls)
• Klinefelter’s syndrome (chromosomal abnormality in boys)
• Chronic infections
• Eating disorder (anorexia nervosa)
Normal range of FSH in First Lab
1.follicle phase 4 – 13
2.mid. phase 5 – 22
3. luteal phase 2 – 13
4. mencapausal 20 – 138
Normal range of LH in First Lab
1.follicle phase 1 – 8
2.mid. phase 24 – 105
3. luteal phase 0.4 – 20
4. mencapausal 15 – 62
Is there anything else I should know about FSH?
FSH results can be increased with use of cimetidine, clomiphene, digitalis, and levodopa. FSH results can decrease with oral contraceptives, phenothiazines, and hormone treatments. FSH has been reported to increase with age and in smokers.
A recent nuclear medicine scan may interfere with results of the FSH test.
Is there anything else I should know about LH?
Some drugs can cause LH to increase, such as anticonvulsants, clomiphene, and naloxone, while others cause LH to decrease, such as digoxin, oral contraceptives, and hormone treatments.