Turner syndrome is a female-only disorder caused by a partial or full deletion of an X chromosome so that women have XO, rather than XX. In affected patients, ovarian function is impaired and therefore luteinising hormone production increases to try to stimulate ovarian function. Too little luteinising hormone will also result in infertility in both men and women, as a critical level of luteinising hormone is required to support testicular or ovarian function.
In women, a lack of luteinising hormone means that ovulation does not occur and menstrual periods may not occur regularly. An example of a condition which can be caused by too little luteinising hormone is amenorrhoea.
About Contact Events News. Search Search. You and Your Hormones. Students Teachers Patients Browse. Human body. Home Hormones Luteinising hormone. Luteinising hormone Luteinising hormone is produced by the pituitary gland and is one of the main hormones that control the reproductive system. Alternative names for luteinising hormone Interstitial cell stimulating hormone; luteinizing hormone; lutropin; LH What is luteinising hormone? How is luteinising hormone controlled?
What happens if I have too much luteinising hormone? What happens if I have too little luteinising hormone? Administration of FSH to humans and animals induces "superovulation", or development of more than the usual number of mature follicles and hence, an increased number of mature gametes.
FSH is also critical for sperm production. It supports the function of Sertoli cells, which in turn support many aspects of sperm cell maturation. GnRH is a ten amino acid peptide that is synthesized and secreted from hypothalamic neurons and binds to receptors on gonadotrophs. As depicted in the figure to the right, GnRH stimultes secretion of LH, which in turn stimulates gonadal secretion of the sex steroids testosterone, estrogen and progesterone.
In a classical negative feedback loop , sex steroids inhibit secretion of GnRH and also appear to have direct negative effects on gonadotrophs. In females, pulse frequency is clearly related to stage of the cycle. Numerous hormones influence GnRH secretion, and positive and negative control over GnRH and gonadotropin secretion is actually considerably more complex than depicted in the figure.
For example, the gonads secrete at least two additional hormones - inhibin and activin - which selectively inhibit and activate FSH secretion from the pituitary. This condition is typically manifest in males as failure in production of normal numbers of sperm.
In females, cessation of reproductive cycles is commonly observed. Elevated blood levels of gonadotropins usually reflect lack of steroid negative feedback. Removal of the gonads from either males or females, as is commonly done to animals, leads to persistent elevation in LH and FSH.
It can last for several years. LH testing may be done towards the end of this transition. In men, these tests are most often used to: Help find the cause of infertility Find the reason for a low sperm count Find the reason for low sex drive In children, these tests are most often used to help diagnose early or delayed puberty. Puberty is considered early if it starts before age 9 in girls and before age 10 in boys. Puberty is considered delayed if hasn't started by age 13 in girls and by age 14 in boys.
Why do I need an LH test? If you are a woman, you may need this test if: You've been unable to get pregnant after 12 months of trying.
Your menstrual cycle is irregular. Your periods have stopped. The test may be used to find out if you have gone through menopause or are in perimenopause. If you are a man, you may need this test if: You've been unable to get your partner pregnant after 12 months of trying. Your sex drive is decreased.
These include some of the symptoms listed above, as well as: Fatigue Weakness Weight loss Decreased appetite Your child may need an LH test if he or she is does not seem to be starting puberty at the right age either too early or too late. What happens during an LH levels test? Will I need to do anything to prepare for the test? Are there any risks to the test? What do the results mean? The meaning of your results will depend on whether you are a woman, man, or child.
If you are woman, high LH levels may mean you: Are not ovulating. If you are of childbearing age, this may mean you have a problem in your ovaries. If you are older, it may mean you have started menopause or are in perimenopause. Have polycystic ovary syndrome PCOS. PCOS is a common hormone disorder affecting childbearing women.
It is one of the leading causes of female infertility. Have Turner syndrome , a genetic disorder affects sexual development in females. It often causes infertility. If you are woman, low LH levels may mean: Your pituitary gland is not working correctly. You have an eating disorder. You have malnutrition. If you are a man, high LH levels may mean: Your testicles have been damaged due chemotherapy , radiation, infection, or alcohol abuse.
You have Klinefelter's syndrome , a genetic disorder that affects sexual development in males. It often causes infertility If you are a man, low LH levels may mean you have a disorder of the pituitary gland or the hypothalamus, a part of the brain that controls the pituitary gland and other important body functions.
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