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Luteinizing hormone is a hormone produced by gonadotropic cells in the anterior pituitary gland. The production of LH is regulated by gonadotropin-releasing hormone (GnRH) from the hypothalamus. In females, an acute rise of LH triggers ovulation and development of the corpus luteum. In males, where LH had also been called interstitial cell–stimulating hormone (ICSH), it stimulates Leydig cell production of testosterone. It acts synergistically with follicle-stimulating hormone (FSH).
The house mouse is a small mammal of the order Rodentia, characteristically having a pointed snout, large rounded ears, and a long and almost hairless tail. It is one of the most abundant species of the genus Mus. Although a wild animal, the house mouse has benefited significantly from associating with human habitation to the point that truly wild populations are significantly less common than the semi-tame populations near human activity.
Xenoestrogens are a type of xenohormone that imitates estrogen. They can be either synthetic or natural chemical compounds. Synthetic xenoestrogens include some widely used industrial compounds, such as PCBs, BPA, and phthalates, which have estrogenic effects on a living organism even though they differ chemically from the estrogenic substances produced internally by the endocrine system of any organism. Natural xenoestrogens include phytoestrogens which are plant-derived xenoestrogens. Because the primary route of exposure to these compounds is by consumption of phytoestrogenic plants, they are sometimes called "dietary estrogens". Mycoestrogens, estrogenic substances from fungi, are another type of xenoestrogen that are also considered mycotoxins.
A gonadotropin-releasing hormone agonist is a type of medication which affects gonadotropins and sex hormones. They are used for a variety of indications including in fertility medicine and to lower sex hormone levels in the treatment of hormone-sensitive cancers such as prostate cancer and breast cancer, certain gynecological disorders like heavy periods and endometriosis, high testosterone levels in women, early puberty in children, as a part of transgender hormone therapy, and to delay puberty in transgender youth among other uses. GnRH agonists are given by injections into fat, as implants placed into fat, and as nasal sprays.
The Lee–Boot effect is a phenomenon concerning the suppression or prolongation of oestrous cycles of mature female mice, when females are housed in groups and isolated from males. It is caused by the effects of an estrogen-dependent pheromone, possibly 2,5-dimethylpyrazine, which is released via the urine and acts on the vomeronasal organ of recipients. This pheromone lowers the concentration of luteinizing hormone and elevates prolactin levels, synchronising or stopping the recipient's cycle. This effect goes some way to explain why spontaneous pseudopregnancy can occur in mice. The same response is invoked from isolated females when brought into contact with urine-soaked bedding from other females' cages. The adrenal glands are required for production of the urine pheromone which is responsible for this effect.
Kisspeptins are proteins encoded by the KISS1 gene in humans. Kisspeptins are ligands of the G-protein coupled receptor, GPR54. Kiss1 was originally identified as a human metastasis suppressor gene that has the ability to suppress melanoma and breast cancer metastasis. Kisspeptin-GPR54 signaling has an important role in initiating secretion of gonadotropin-releasing hormone (GnRH) at puberty, the extent of which is an area of ongoing research. Gonadotropin-releasing hormone is released from the hypothalamus to act on the anterior pituitary triggering the release of luteinizing hormone (LH), and follicle stimulating hormone (FSH). These gonadotropic hormones lead to sexual maturation and gametogenesis. Disrupting GPR54 signaling can cause hypogonadotrophic hypogonadism in rodents and humans. The Kiss1 gene is located on chromosome 1. It is transcribed in the brain, adrenal gland, and pancreas.
The Whitten effect is stimulation, by male pheromones, of synchronous estrus in a female population.
Deslorelin, sold under the brand names Ovuplant, SucroMate, and Suprelorin among others, is an injectable gonadotropin releasing hormone superagonist which is used in veterinary medicine for various indications.
Puberty is the process of physical changes through which a child's body matures into an adult body capable of sexual reproduction. It is initiated by hormonal signals from the brain to the gonads: the ovaries in a girl, the testes in a boy. In response to the signals, the gonads produce hormones that stimulate libido and the growth, function, and transformation of the brain, bones, muscle, blood, skin, hair, breasts, and sex organs. Physical growth—height and weight—accelerates in the first half of puberty and is completed when an adult body has been developed. Before puberty, the external sex organs, known as primary sexual characteristics, are sex characteristics that distinguish boys and girls. Puberty leads to sexual dimorphism through the development of the secondary sex characteristics, which further distinguish the sexes.
Major urinary proteins (Mups), also known as α2u-globulins, are a subfamily of proteins found in abundance in the urine and other secretions of many animals. Mups provide a small range of identifying information about the donor animal, when detected by the vomeronasal organ of the receiving animal. They belong to a larger family of proteins known as lipocalins. Mups are encoded by a cluster of genes, located adjacent to each other on a single stretch of DNA, that varies greatly in number between species: from at least 21 functional genes in mice to none in humans. Mup proteins form a characteristic glove shape, encompassing a ligand-binding pocket that accommodates specific small organic chemicals.
The Bruce effect, or pregnancy block, is the tendency for female rodents to terminate their pregnancies following exposure to the scent of an unfamiliar male. The effect was first noted in 1959 by Hilda M. Bruce, and has primarily been studied in laboratory mice. In mice, pregnancy can only be terminated prior to embryo implantation, but other species will interrupt even a late-term pregnancy.
Vandenbergh is a surname. Notable people with the surname include:
Hilda Margaret Bruce was a British zoologist, best known for her discovery of the Bruce effect, a pheromonal behaviour observed in many rodent species. Her work on the control of fertility earned her the Oliver Bird Medal.
Hormonal regulation occurs at every stage of development. A milieu of hormones simultaneously affects development of the fetus during embryogenesis and the mother, including human chorionic gonadotropin (hCG) and progesterone (P4).
Gonadotropin-releasing hormone (GnRH) insensitivity also known as Isolated gonadotropin-releasing hormone (GnRH)deficiency (IGD) is a rare autosomal recessive genetic and endocrine syndrome which is characterized by inactivating mutations of the gonadotropin-releasing hormone receptor (GnRHR) and thus an insensitivity of the receptor to gonadotropin-releasing hormone (GnRH), resulting in a partial or complete loss of the ability of the gonads to synthesize the sex hormones. The condition manifests itself as isolated hypogonadotropic hypogonadism (IHH), presenting with symptoms such as delayed, reduced, or absent puberty, low or complete lack of libido, and infertility, and is the predominant cause of IHH when it does not present alongside anosmia.
The Great Pheromone Myth is a book on pheromones and their application to chemosensation in mammals by Richard Doty, director of the University of Pennsylvania's Smell and Taste Center in Philadelphia. Doty argues that the concept of pheromone introduced by Karlson and Lüscher is too simple for mammalian chemonsensory systems, failing to take into account learning and the context-dependence of chemosensation. In this book, he is especially critical of human pheromones, arguing that not only are there no definitive studies finding human pheromones, but that humans lack a functional vomeronasal organ to detect pheromones. Its publication received coverage in the news media, especially concerning its arguments that human pheromones do not exist.
Induced ovulation is when a female animal ovulates due to an externally-derived stimulus during, or just prior to, mating, rather than ovulating cyclically or spontaneously. Stimuli causing induced ovulation include the physical act of coitus or mechanical stimulation simulating this, sperm and pheromones.
The Hoover-Drickamer effect occurs when adult female mice are exposed to the urine of pregnant and lactating adult female mice, resulting in a longer than typical oestrus period. The effect was first noted by J. E. Hoover and L. C. Drickamer in their 1979 study wherein they randomly assigned adult female mice to one of four treatment conditions: a control group where the subjects were exposed to water, a group that was exposed to the urine of pregnant mice, a group that was exposed to the urine of lactating mice and a group that was exposed to the urine of a singly caged female mouse.
Gonadotropin surge-attenuating factor (GnSAF) is a nonsteroidal ovarian hormone produced by the granulosa cells of small antral ovarian follicles in females. GnSAF is involved in regulating the secretion of luteinizing hormone (LH) from the anterior pituitary and the ovarian cycle. During the early to mid-follicular phase of the ovarian cycle, GnSAF acts on the anterior pituitary to attenuate LH release, limiting the secretion of LH to only basal levels. At the transition between follicular and luteal phase, GnSAF bioactivity declines sufficiently to permit LH secretion above basal levels, resulting in the mid-cycle LH surge that initiates ovulation. In normally ovulating women, the LH surge only occurs when the oocyte is mature and ready for extrusion. GnSAF bioactivity is responsible for the synchronised, biphasic nature of LH secretion.
Non-surgical fertility control is the prevention of reproduction without the use of surgery. The most common form of sterilization in dogs and cats is surgical, spaying in females and castration in males. Non-surgical fertility control can either result in sterilization or temporary contraception and could offer a cheaper way to keep wild dog and cat populations under control. As of 2019, only contraceptives are commercially available. Research is ongoing into methods that could result in permanent suppression of fertility.
References
- ↑ Vandenbergh JG, Whitsett JM, Lombardi JR (1975). "Partial isolation of a pheromone accelerating puberty in female mice". Journal of Reproduction and Fertility. 43 (3): 515–23. doi: 10.1530/jrf.0.0430515 . PMID 1142335.
- ↑ Carlson, Neil R. (2013). Physiology of behavior (11th ed.). Boston: Pearson. p. 335. ISBN 978-0205239399.
- ↑ An Introduction to Behavioral Endocrinology, 3rd edition. Randy J. Nelson. Sinauer Associates, 2005.[ page needed ]
- ↑ Sapolsky, Robert M. (June 1992). "Why Teenage Girls Are Hitting Puberty At an Earlier Age". Discover Magazine.
- ↑ Guzzo AC, Jheon J, Imtiaz F, deCatanzaro D (2012). "Oestradiol transmission from males to females in the context of the Bruce and Vandenbergh effects in mice (Mus musculus)". Reproduction. 143 (4): 539–48. doi: 10.1530/REP-11-0375 . PMID 22232744.
- ↑ Thorpe JB, deCatanzaro D (2012). "Oestradiol treatment restores the capacity of castrated males to induce both the Vandenbergh and the Bruce effects in mice (Mus musculus)". Reproduction. 143 (1): 123–32. doi: 10.1530/REP-11-0251 . PMID 22016382.
