^
Fact-checked
х

All iLive content is medically reviewed or fact checked to ensure as much factual accuracy as possible.

We have strict sourcing guidelines and only link to reputable media sites, academic research institutions and, whenever possible, medically peer reviewed studies. Note that the numbers in parentheses ([1], [2], etc.) are clickable links to these studies.

If you feel that any of our content is inaccurate, out-of-date, or otherwise questionable, please select it and press Ctrl + Enter.

Study of hormonal regulation of reproductive function

Medical expert of the article

Vascular surgeon, radiologist
, medical expert
Last reviewed: 06.07.2025

Radiation study of hormonal regulation of the reproductive function of the female body

Regulation of all functions of the female reproductive system occurs with the participation of the cerebral cortex, subcortical structures, pituitary gland, ovaries, as well as the uterus, vagina, and mammary glands. The interconnection and coordinated interaction of all elements of this complex system are carried out using a mechanism of multi-stage negative and positive feedback. Violation of one of the links in the chain of regulatory mechanisms is inevitably accompanied by a deregulation of the remaining hormonal relationships. Radioimmunological diagnostic methods allow these violations to be detected already at early stages.

Radioimmunological studies of a woman’s hormonal status are performed with a portion of blood (in vitro), i.e. without introducing radioactive compounds into the body, so they do not pose a danger to either the pregnant woman or the embryo.

The menstrual cycle of a healthy woman is biphasic. In the first phase - growth and maturation of the follicle (estrogenic, or follicular, phase) - the ovaries secrete the hormone estradiol into the blood. Its concentration is 0.1-0.3 nmol/l and increases as the follicle matures. The maximum concentration - 0.6-1.3 nmol/l - is observed in the middle of the cycle, 1-2 days before ovulation. In the second phase of the cycle - the corpus luteum phase (luteal phase) - the estradiol level decreases to 0.3-0.8 nmol/l. Estradiol causes proliferation of the uterine mucosa.

Another hormone produced by the ovaries is progesterone. It is secreted mainly by the corpus luteum and, therefore, its concentration is maximum in the second phase of the menstrual cycle - 25-55 nmol/l, while in the first phase of the cycle - only 2 - 6 nmol/l. The function of progesterone is to prepare the endometrium for implantation of the fertilized egg.

Changes in the secretion of sex hormones are regulated by the pituitary gland by secreting gonadotropic hormones - lutropin and follitropin, as well as prolactin. Lutropin stimulates the biosynthesis of progesterone and regulates the function of the corpus luteum. It is a factor in triggering ovulation. The content of lutropin at the beginning and end of the cycle is 7-15 U/L, and at the peak of ovulation it rises to 40-100 U/L.

Follitropin stimulates the growth of ovarian granular cells and promotes follicle maturation. Like lutropin, it triggers the ovulation mechanism. Its blood concentration fluctuations are similar to those of lutropin: it is minimal at the beginning and end of the cycle (6-12 U/L) and maximal at the peak of ovulation (20-40 U/L).

The physiological role of prolactin is varied. Like luteinizing hormone, it stimulates the secretion of progesterone by the corpus luteum. Fluctuations in its blood levels are subject to the same patterns as luteinizing hormone: the peak is observed during the ovulation phase, i.e. in the middle of the menstrual cycle. Prolactin concentrations increase sharply during pregnancy and lactation.

The gonadotropic function of the pituitary gland is controlled by the hypothalamus. The latter produces releasing hormones: lulliberin and folliberin, which stimulate the secretion of gonadotropins. Recently, synthetic hypothalamic releasing hormones have been created, which are used in radioimmunological diagnostics to differentiate between lesions of the hypothalamus and pituitary gland. Particularly accurate radioimmunological methods have also been developed that allow determining the concentration of releasing hormones in the blood. This opens the possibility for a one-time radioimmunological study of the entire hormonal "hierarchy": hypothalamus - pituitary gland - ovaries.


The iLive portal does not provide medical advice, diagnosis or treatment.
The information published on the portal is for reference only and should not be used without consulting a specialist.
Carefully read the rules and policies of the site. You can also contact us!

Copyright © 2011 - 2025 iLive. All rights reserved.