Luteinizing Hormone: Characteristics, Effects And Functions In The Body
The pituitary gland is responsible for producing luteinizing hormone, also known as LH. In women, LH is responsible for progesterone production, follicle maturation, and ovulation. It is an essential hormone for female fertility. In men, it is also related to reproductive capacity; LH directly affects sperm production by acting on the testicles.
LH is commonly used in ovulation tests for people looking to get pregnant. Also, LH levels in the blood can indicate underlying problems associated with various reproductive health problems. LH is used in the diagnosis of gynecological disorders, along with pituitary tumors and ovarian problems, such as cysts. The level of LH in the blood can be used to check gynecological health, along with FSH and gonadotropin-releasing hormone, or GnRH. In this article we will explain in detail the functions of luteinizing hormone and what underlying pathologies may indicate altered levels of it.
The pituitary gland (hypophysis) is a small, pea-sized gland located in the back of the brain. It is also known as the “master gland” of the body, since it regulates different activities of other endocrine glands and is responsible for the production of different hormones.
The pituitary gland secretes luteinizing hormone, also known as LH or lutropin , which is an important hormone for menstruating people in the development of the menstrual cycle. LH is present throughout the life of menstruating people and is essential for the correct functioning of the menstrual cycle. Its concentration changes depending on the part of the cycle in which it is found, allowing for the different stages. During ovulation, luteinizing hormone concentrations are higher than in other phases.
In the case of males, the luteinizing hormone stimulates testosterone production Testosterone is a sex hormone necessary for sperm production, so the level in the testicles, where sperm is produced, is higher than the level in the blood.
How does luteinizing hormone act in the body?
Lutropin is a hormone that mainly affects the reproductive system , so it will act differently in individuals of different sexes. In the case of females, the hormone is closely related to menstruation, in males it has an essential role in the production of testosterone.
1. Functions of LH in female people
Luteinizing hormone along with follicle-stimulating hormone (FSH), another gonadotropin produced in the pituitary gland, controls the different phases of the period. The follicles – which contain the eggs in the ovaries – respond to the production of FSH, which also stimulates the production of estrogen within them.
Estrogens play a role in the production of LH and the decrease of FSH. Increased estrogen levels cause the pituitary gland to stop producing FSH and start producing more LH. High LH levels allow the release of the egg from the ovary In the follicle, now empty, cell proliferation begins and becomes the corpus luteum. The main role of the corpus luteum is the production of progesterone for the establishment and maintenance of pregnancy. If there is no fertilization, progesterone levels drop and the cycle begins again.
2. Functions of LH in males
In males, luteinizing hormone, sIt binds to cells in the testicles called Leydig cells This hormone causes the release of testosterone, a sex hormone that helps maintain male secondary sexual characteristics such as muscle mass and necessary for sperm production. Testosterone levels affect overall male health.
3. Other functions of the LH
Steroid hormones, such as progesterone and testosterone, are synthesized from cholesterol. The first precursor of sex hormones is pregnenolone. LH helps cholesterol enter the mitochondria, where it is converted into pregnenolone.
LH contributes to the increase in concentrations of enzymes, protagonists of the set of metabolic reactions that allow the synthesis of steroid hormones. LH stimulates the production of androgens in particular, by increasing the expression of their genes
As we have already indicated previously in the article, the levels of the LH hormone present in the bloodstream of a menstruating person change throughout the menstrual cycle. Furthermore, the different levels of LH that occur in the menstrual cycle are not constant over time; they are generally lower as we age. LH levels, like other sex hormones, are also altered during pregnancy
An LH blood test measures the amount of the hormone in the bloodstream. A person may need to have several LH tests if they are undergoing a fertility study, to monitor the levels of the hormone in different phases of the cycle. LH can also be measured with a urine sample.
In the case of men. LH levels can be measured either naturally and compared to a reference value and/or after injecting a gonadotropin-releasing hormone. Levels are measured after the gonadotropin injection to check if there is a problem with the pituitary gland or another part of the body.
What is the luteinizing hormone test for?
There are many reasons why an LH measurement may be requested. Alterations in LH levels are frequently related to menstrual problems, fertility problems, and the onset of puberty. Below we explore the different common uses of LH testing:
1. Fertility problems
A measurement of LH blood levels may be requested if they exist difficulties with conception Doctors use LH tests to measure reproductive capacity and fertility problems, which occur in both female and male people.
There are different conditions related to LH that can affect reproductive capacity and the possibility of pregnancy. Frequently, altered levels indicate that there may be a problem with the number of sperm or the supply of eggs to the ovaries.
A person’s LH blood tests allow the doctor to determine whether the problem is with the sperm count or egg supply. Either of these two conditions can make conception difficult.
2. Ovulation
During the menstrual cycle, There are approximately 6 days in which a person can get pregnant The best time to attempt conception is around the time of ovulation. On different days, people trying to get pregnant can measure their LH levels to find out how fertile they are. As we have seen, LH levels increase before ovulation to allow release from the ovary. This is the most fertile time in the cycle, as the released ovary can be fertilized. Urine tests can be used to identify the fertile period of the cycle. The tests detect the LH surge that occurs approximately 1-1.5 days before ovulation.
The ovulation kits sold in pharmacies usually contain several urine tests. The best time to use them is around days 13, 14 or 15 when the middle of the menstrual cycle occurs, if you have regular 28-day periods. This helps determine when you are about to ovulate.
You may be interested: “Why the menstrual cycle can affect sleep”
3. Menstrual changes
High levels of LH in people over 50 may indicate the beginning of menopause LH tests can help diagnose menstrual changes or problems that occur early.
4. Precocious or late puberty
The changes in puberty include the growth of pubic hair in both sexes, the development of the testicles and penis in males, and the growth of the breast and the onset of menstruation in females. These changes are related with higher levels of LH.
High LH levels are associated with early puberty. On the contrary, low LH levels are associated with a late puberty Therefore, LH tests can help the doctor determine if there is an early or late onset of puberty and prescribe some type of treatment if necessary.
5. Pituitary gland problems
LH is produced in the pituitary gland; if it is affected, LH levels may be altered. A test of LH levels can help determine if there is a problem with the pituitary gland, such as a pituitary tumor
6. Low testosterone levels
LH contributes to the production of testosterone. Low testosterone levels are associated with the appearance of different symptoms, such as:
