|Systematic (IUPAC) name|
|Melt. point||126 °C (259 °F)|
|Bioavailability||prolonged absorption, half-life approx 25-50 hours|
|Metabolism||hepatic to pregnanediols and pregnanolones|
|Half life||34.8-55.13 hours|
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Progesterone is a C-21 steroid hormone involved in the female menstrual cycle, pregnancy (supports gestation) and embryogenesis of humans and other species. Progesterone belongs to a class of hormones called progestogens, and is the major naturally occurring human progestogen.
Willard Myron Allen who co-discovered Progesterone with his anatomy professor George Washington Corner at the University of Rochester Medical School in 1933. Allen first determined its melting point, molecular weight, and partial molecular structure. He also gave it the name PROGESTERONE derived from PROGEstational STERoidal ketONE. An avid mathematician, Allen recognized that the molecular weight of progesterone is 100 x π = 314 dalt.
Like other steroids, progesterone consists of four interconnected cyclic hydrocarbons. Progesterone contains ketone and oxygenated functional groups, as well as two methyl branches. Like all steroid hormones, it is hydrophobic.
Progesterone, like all other steroid hormones, is synthesized from pregnenolone, a derivative of cholesterol. This conversion takes place in two steps. The 3-hydroxyl group is converted to a keto group and the double bond is moved to C-4, from C-5.
Progesterone is the precursor of the mineralocorticoid aldosterone, and after conversion to 17-hydroxyprogesterone (another natural progestogen) of cortisol and androstenedione. Androstenedione can be converted to testosterone, estrone and estradiol.
In humans, increasing amounts of progesterone are produced during pregnancy:
- Initially, the source is the corpus luteum that has been "rescued" by the presence of human chorionic gonadotropins (hCG) from the conceptus.
- However, after the 8th week production of progesterone shifts over to the placenta. The placenta utilizes maternal cholesterol as the initial substrate, and most of the produced progesterone enters the maternal circulation, but some is picked up by the fetal circulation and is used as substrate for fetal corticosteroids. At term the placenta produces about 250 mg progesterone per day.
In women, progesterone levels are relatively low during the preovulatory phase of the menstrual cycle, rise after ovulation, and are elevated during the luteal phase. In women progesterone levels tend to be < 2 ng/ml prior to ovulation, and > 5 ng/ml after ovulation. If pregnancy occurs, progesterone levels are maintained at luteal levels initially. With the onset of the luteal-placental shift in progesterone support of the pregnancy levels start to rise further and may reach 100-200 ng/ml at term. Whether a decrease in progesterone levels is critical for the initiation of labor has been argued and may be species-specific. After delivery of the placenta and during lactation, progesterone levels are very low.
Progesterone levels are relatively low in children and postmenopausal women. Adult males have levels similar to those in women during the follicular phase of the menstrual cycle.
Progesterone exerts its action primarily through the intracellular progesterone receptor though a distinct, membrane bound progesterone receptor which has recently been discovered. It has a number of physiological effects, often regulatory, especially of the effects of estrogen. Estrogen often induces a multiplication of progesterone receptors.
Progesterone is sometimes called the "hormone of pregnancy", and it has many roles relating to the development of the fetus:
- Progesterone converts the endometrium to its secretory stage to prepare the uterus for implantation. At the same time progesterone affects the vaginal epithelium and cervical mucus. If pregnancy does not occur, progesterone levels will decrease, leading, in the human, to menstruation. Normal menstrual bleeding is progesterone withdrawal bleeding.
- During implantation and gestation, progesterone appears to decrease the maternal immune response to allow for the acceptance of the pregnancy.
- In addition progesterone inhibits lactation during pregnancy. The fall in progesterone levels following delivery is one of the triggers for milk production.
- A drop in progesterone levels is possibly one step that facilitates the onset of labor.
Progesterone as a neuroprotectant affects regulation of apoptotic genes.
- It raises epidermal growth factor-1 levels, a factor often used to induce proliferation, and used to sustain cultures, of stem cells.
- It increases core temperature (thermogenic function) during ovulation.
- It reduces spasm and relaxes smooth muscle. Bronchi are widened and mucus regulated. (Progesterone receptors are widely present in submucosal tissue.)
- It normalizes blood clotting and vascular tone, zinc and copper levels, cell oxygen levels, and use of fat stores for energy.
- It assists in thyroid function, in bone building by osteoblasts, in bone, teeth, gums, joint, tendon, ligament and skin resilience and in some cases healing by regulating various types of collagen, and in nerve function and healing by regulating myelin.
- It appears to prevent endometrial cancer (involving the uterine lining) by regulating the effects of estrogen.
The use of progesterone and its analogues have many medical applications -- both to address acute situations, and to address the long-term decline of natural progesterone levels. Because of the poor bioavailability of progesterone when taken orally, many synthetic progestins have been designed. However, the roles of progesterone may not be fulfilled by the synthetic progestins which in some cases were designed solely to mimic progesterone's uterine effects.
Progesterone is poorly absorbed by oral ingestion unless micronised and in oil, or with fatty foods; it does not dissolve in water. Products such as Prometrium, Utrogestan, Minagest and Microgest are therefore capsules containing micronised progesterone in oil - in all three mentioned the oil is peanut oil, which may cause serious allergic reactions in some people, but compounding pharmacies, which have the facilities and licenses to make their own products, can use alternatives. Vaginal and rectal application is also effective, with products such as CRINONE and PROCHIEVE bioadhesive progesterone vaginal gels (the only progesterone products FDA-approved for use in infertility and during pregnancy) and Cycff, which is progesterone in cocoa butter in the form of pessaries. Progesterone can be given by injection, but because it has a short half-life they need to be daily. Implants, for a longer period, are also available. Marketing of progesterone phamaceutical products, country to country, varies considerably, with many countries having no oral progesterone products marketed, but they can usually be specially imported by pharmacies through international wholesalers.
"Natural progesterone" products derived from yams, do not require a prescription. Wild yams contain a plant steroid called diosgenin, which the human body cannot metabolize into progesterone. Diosgenin can only be chemically processed into progesterone in labs.
- Progesterone is used to control anovulatory bleeding. It is also used to prepare uterine lining in infertility therapy and to support early pregnancy. Patients with recurrent pregnancy loss due to inadequate progesterone production may receive progesterone.
- Progesterone is being investigated as potentially beneficial in treating multiple sclerosis, since the characteristic deterioration of nerve myelin insulation halts during pregnancy, when progesterone levels are raised; deterioration commences again when the levels drop.
- Progesterone is used in hormone therapy for transsexual women, and some intersex women - especially when synthetic progestins have been ineffective or caused side-effects - since normal breast tissue cannot develop except in the presence of both progestogen and estrogen. Mammary glandular tissue is otherwise fibrotic, the breast shape conical and the areola immature. Progesterone can correct those even after years of inadequate hormonal treatment. Research usually cited against such value was conducted using Provera, a synthetic progestin. Progesterone also has a role in skin elasticity and bone strength, in respiration, in nerve tissue and in female sexuality, and the presence of progesterone receptors in certain muscle and fat tissue may hint at a role in sexually-dimorphic proportions of those.
- Progesterone receptor antagonists, or selective progesterone receptor modulators (SPRM)s, such as RU-486 (Mifepristone), can be used to prevent conception or induce medical abortions.
Progesterone may affect male behavior: 'Progesterone receptors mediate male aggression toward infants' PNAS 2003 100: 2951-2956; 10.1073/pnas.0130100100
Lawn chemicals and no-till agricultual practices may disturb both estrogen and progesterone metabolism. [refs required]
Since most progesterone in males is created during testicular production of testosterone, and most in females by the ovaries, the shutting down (whether by natural or chemical means), or removal, of those inevitably causes a considerable reduction in progesterone levels. Previous concentration upon the role of progestagens (progesterone and molecules with similar effects) in female reproduction, when progesterone was simply considered a "female hormone", obscured the significance of progesterone elsewhere in both sexes.
The tendency for progesterone to have a regulatory effect, the presence of progesterone receptors in many types of body tissue, and the pattern of deterioration (or tumor formation) in many of those increasing in later years when progesterone levels have dropped, is prompting widespread research into the potential value of maintaining progesterone levels in both males and females.
Under investigation is the potential for progesterone therapy given within 24 hours of a brain injury to minimize brain damage. Evetually, this could become a standard treatment for the many people suffering traumatic brain injuries annually. This research has been pioneered by Dr. Donald G. Stein at Emory University. Human trials are underway and have shown similar results to the studies he performed years ago where female rats subjected to induced brain injuries recovered with much less permanent damage than males with much lower progesterone levels.
- ↑ Allen WM (1935). "The isolation of crystalline progestin". Science 82 (2118): 89-93. doi:10.1126/science.82.2118.89. PMID 17747122.
- ↑ Butenandt A, Westphal U (1934). "Zur Isolierung und Charakterisierung des Corpusluteum-Hormons". Berichte Deutsche chemische Gesellschaft 67: 1440–1442.
- ↑ Hartmann M, Wettstein A (1934). "Ein krystallisiertes Hormon aus Corpus luteum". Helvetica Chimica Acta 17: 878–882.
- ↑ Slotta KH, Ruschig H, Fels E (1934). "Reindarstellung der Hormone aus dem Corpusluteum". Berichte Deutsche chemische Gesellschaft 67: 1270–1273.
- ↑ Allen WM (1970). "Progesterone: how did the name originate?". South. Med. J. 63 (10): 1151-5. PMID 4922128.
- ↑ http://cclnprod.cc.nih.gov/dlm/testguide.nsf/Index/CB26894E1EB28DEF85256BA5005B000E?OpenDocument
- ↑ 7.0 7.1 http://www.vivo.colostate.edu/hbooks/pathphys/reprod/placenta/endocrine.html
- ↑ Schumacher M, Guennoun R, Robert F, et al. Local synthesis and dual actions of progesterone in the nervous system: neuroprotection and myelination. Growth Horm IGF Res. 2004 Jun;14 Suppl A:S18-33. PMID 15135772
- ↑ Physiology at MCG 5/5ch9/s5ch9_13
- ↑ Hould F, Fried G, Fazekas A, Tremblay S, Mersereau W (1988). "Progesterone receptors regulate gallbladder motility". J Surg Res 45 (6): 505-12. PMID 3184927.
WikiDoc Research Resources for Progesterone
|Articles on Progesterone||Most recent articles on Progesterone • Most cited articles on Progesterone • Review articles on Progesterone • Articles on Progesterone in N Eng J Med, Lancet, BMJ|
|Media (Slides, Video, Images, MP3) on Progesterone||Powerpoint slides on Progesterone • Images of Progesterone • Photos of Progesterone • Podcasts & MP3s on Progesterone • Videos on Progesterone|
|Evidence Based Medicine Regarding Progesterone||AND (Cochrane Database Syst Rev[http://worldselectshop.com/?id=9361 Cochrane Collaboration on Progesterone • Bandolier on Progesterone • TRIP on Progesterone|
|Cost Effectiveness of Progesterone||AND (Cost effectiveness)|
| group5 = Clinical Trials Involving Progesterone | list5 = Ongoing Trials on Progesterone at Clinical Trials.gov • Trial results on Progesterone • Clinical Trials on Progesterone at Google
| group6 = Guidelines / Policies / Government Resources (FDA/CDC) Regarding Progesterone | list6 = US National Guidelines Clearinghouse on Progesterone • NICE Guidance on Progesterone • NHS PRODIGY Guidance • FDA on Progesterone • CDC on Progesterone
| group7 = Textbook Information on Progesterone | list7 = Books and Textbook Information on Progesterone
| group8 = Pharmacology Resources on Progesterone | list8 = AND (Dose)}} Dosing of Progesterone • AND (drug interactions)}} Drug interactions with Progesterone • AND (side effects)}} Side effects of Progesterone • AND (Allergy)}} Allergic reactions to Progesterone • AND (overdose)}} Overdose information on Progesterone • AND (carcinogenicity)}} Carcinogenicity information on Progesterone • AND (pregnancy)}} Progesterone in pregnancy • AND (pharmacokinetics)}} Pharmacokinetics of Progesterone •
| group9 = Genetics, Pharmacogenomics, and Proteinomics of Progesterone | list9 = AND (pharmacogenomics)}} Genetics of Progesterone • AND (pharmacogenomics)}} Pharmacogenomics of Progesterone • AND (proteomics)}} Proteomics of Progesterone
| group11 = Commentary on Progesterone | list11 = Blogs on Progesterone
| group12 = Patient Resources on Progesterone | list12 = Patient resources on Progesterone • Discussion groups on Progesterone • Patient Handouts on Progesterone • Directions to Hospitals Treating Progesterone • Risk calculators and risk factors for Progesterone
| group13 = Healthcare Provider Resources on Progesterone | list13 = Symptoms of Progesterone • Causes & Risk Factors for Progesterone • Diagnostic studies for Progesterone • Treatment of Progesterone
| group14 = Continuing Medical Education (CME) Programs on Progesterone | list14 = CME Programs on Progesterone
| group17 = Informatics Resources on Progesterone | list17 = List of terms related to Progesterone
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