LH interacts with receptors on ovarian follicles and promotes their maturation. In the middle of the menstrual cycle, a surge of LH triggers ovulation and production of progesterone by the corpus luteum that is necessary for the maturation of the uterine endometrium for implantation of the fertilized egg.
In males, LH stimulates production of testosterone by the testes. Both urinary derived menotropin, Menopur, which also has FSH activity and recombinant forms lutropin alfa: Luveris of human LH have been developed, but not all are available in the United States.
LH is generally administered by subcutaneous injection in a cyclic and step-wise fashion. The dosages and regimens of administration vary by indication. Human chorionic gonadotropin kor" ee on' ik hCG is a polypeptide hormone produced by the placenta following implantation of the fertilized egg. Circulating human chorionic gonadotropin interacts with the luteinizing hormone receptors of the ovary, promoting the corpus luteum and its production of progesterone which is necessary to maintain pregnancy and support the growth of the fetus.
Injections of hCG mimic the surge in LH that is necessary for ovulation and are used in the therapy of female infertility, in assisted reproduction techniques. Subsequently, recombinant forms of hCG have been developed and licensed for use. Currently, hCG is available as a powder or in solution generically and under trade names such as Novarel and Pregnyl. This stimulates a large increase in gonadotrophin-releasing hormone secretion and, consequently, a surge of luteinising hormone, which stimulates the release of a mature egg.
This process is called ovulation. It is not known what the effects are of having too much gonadotrophin-releasing hormone. Extremely rarely, pituitary adenomas tumours can develop, which increase production of gonadotrophins leading to overproduction of testosterone or oestrogen.
A deficiency of gonadotrophin-releasing hormone in childhood means that the individual does not go through puberty. It is more common in men than women and leads to loss of development of the testes or ovaries and infertility. Any trauma or damage to the hypothalamus can also cause a loss of gonadotrophin-releasing hormone secretion, which will stop the normal production of follicle stimulating hormone and luteinising hormone, causing loss of menstrual cycles amenorrhoea in women, loss of sperm production in men, and loss of production of hormones from the testes and ovaries.
About Contact Events News. Search Search. Late Effects of Childhood Cancer Treatment. Pediatric Supportive Care. Rare Cancers of Childhood Treatment.
Childhood Cancer Genomics. Study Findings. Metastatic Cancer Research. Intramural Research. Extramural Research. Cancer Research Workforce. Partners in Cancer Research. What Are Cancer Research Studies. Research Studies. Get Involved. Cancer Biology Research. Cancer Genomics Research. Research on Causes of Cancer. Cancer Prevention Research. Cancer Treatment Research. Cancer Health Disparities. Childhood Cancers Research.
Global Cancer Research. Cancer Research Infrastructure. Clinical Trials. Frederick National Laboratory for Cancer Research. Bioinformatics, Big Data, and Cancer. Annual Report to the Nation. Research Advances by Cancer Type. Stories of Discovery. Milestones in Cancer Research and Discovery. Biomedical Citizen Science. Director's Message. Budget Proposal. The main physiological role of gonadotropin is to stimulate the growth and the activity of the target cells.
The gonadotropins act on various cell types. However, the primary target organ is the gonads e. Gonadotropins are essential in the regulation of the normal growth, sexual development, and reproductive activities or functions. For instance, LH stimulates target gonadal cells e. Deficiency of gonadotropin such as in the case of pituitary disease may lead to hypogonadism, which in turn may lead to infertility.
0コメント