One of the peptides( biologically active substances) synthesized in the human pituitary is called luteinizing hormone. Formed in the pituitary gland, along the bloodstream, it enters the sex glands, which are for him a target. The goal of producing luteinizing hormone( abbreviated LH) is to maintain the function of reproduction in the body of both men and women. However, the LH norm may fluctuate depending on certain conditions.
Norm
Such a value as the level of LH in the blood and its fluctuations are different in women and men. But apart from sex differences, age can influence the testimony of the analysis. By the way, before reaching adolescence, when the onset of puberty starts, in women and men( more precisely, boys and girls), the pituitary gland produces the same amount of luteinizing hormone: its values range from 0.03 to 3.9 mIU / ml. Usually such equality lasts until the age of eleven.
After this age in men, the norm of LH in the blood increases to 0.8-8.4 mIU / ml. Unlike women, they have a very stable hormone level.
In women, except for age changes, the level of luteinizing hormone is affected by such conditions as pregnancy and menstrual cycle.
In fertile women, that is, those that are of childbearing age and are capable of reproduction, on different days of the menstrual cycle, the level of LH differs significantly. The follicular period( the first two weeks of the cycle) is marked by normal indices of 1,1-8,7 mIU / ml. But already on the day of egg ripening the analysis will show a completely different picture: when ovulating the luteinizing hormone in the blood grows at times: up to 72 mIU / ml. Following ovulation is the so-called luteal phase, for which the normal is 0.9-14.4 mIU / ml.
It should be noted that for normal reproductive function, it is necessary that the body maintain a normal ratio of LH to another gonadotropin - follicle-stimulating.
As the person ages, the reproductive function in his body goes away, the sex glands become less and less active, while the level of luteinizing hormone normally rises.
Menopausal changes in the female body lead to the fact that the pituitary gland produces a stable amount of LH - 18-72 mIU / ml.
A normal phenomenon for men in the elderly( over 60 years) is an increase in the concentration of this peptide in the blood, and this happens gradually. The normal level of LH in elderly men is not less than 8.4 mIU / ml.
The role of LH in the human body
Luteinizing hormone is necessary for maturation of gametes( gametes).Without this process, reproductive function is impossible.
The biological effect of this gonadotropin for men and women is manifested in the following:
- in women:
- is stimulated by the secretion of estrogens;
- there is an exit of the ripened egg from the follicle( actually, this is called ovulation);
- formed a yellow body;
- increases the production of progesterone;
- in men:
- increases the production of testosterone;
- mature sperm.
Nature has foreseen that in women of reproductive age the high concentration of LH in the blood affects both the yield of the matured egg and the sex drive: it increases. This maximizes the possibility of conception.
As the body ages, the effect of the luteinizing hormone gradually begins to lose its meaning: the body ceases to be receptive to this gonadotropin. The analysis can show an increasing concentration of it to the blood, but the aged sex glands do not perceive it. Therefore, even the off-scale tests of LH do not give reason to hope for the restoration of the menstrual cycle and the onset of ovulation in the menopausal period in women and on the increase in testosterone levels in elderly men. That is, the reproductive function is over.
But the hormone produced by the pituitary gland of older women can help others: with normal post-menopausal tests, blood fetuses are made to obtain pharmacological preparations based on this hormone. These drugs are used for hormonal therapy and drug treatment of female infertility.
When and how to take the
test Analyzes for determining the concentration of luteinizing hormone in the body are done only according to the doctor's prescription - as a rule, these are gynecologists or andrologists( doctors engaged in masculine health), and endocrinologists. Decipher the analysis data, too, can only be a specialist. For women, the accuracy of the analysis is influenced by the menstrual cycle day.
For women, the analysis is prescribed if:
- they have amenorrhea( no menstruation);
- is disrupted by the menstrual cycle;
- allocation is too meager and last less than 3 days;
- is diagnosed with infertility;
- a second miscarriage occurs;
- decreased libido( sexual desire);
- there is abundant hairiness in the male type( hirsutism).
The latter is very often one of the main symptoms of polycystic ovary syndrome. Also, the reason for the study of the level of LH are:
- deviations in sexual development( lagging or too early and violent);
- uterine bleeding;
- endometriosis.
Analysis of this gonadotropin is among other things a very accurate tool for determining ovulation, so it is used in artificial insemination and hormone control therapy.
Accurate analysis results are obtained on certain days of the menstrual cycle: from 3 to 8-1 and from 19 to 21.
It is much easier for men, their level of LH is stable, so you can take blood for analysis on any day on an empty stomach.
