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Progestins are synthetic〔(Merriam-Webster's medical Dictionary > progestin ) Retrieved on Feb 13, 2010〕 progestogens that have progestogenic effects similar to those of progesterone.〔(MedicineNet > progestin definition ) Last Editorial Review: 6/14/2012〕 The two most common uses of progestins are for hormonal contraception (either alone or with an estrogen), and to prevent endometrial hyperplasia from unopposed estrogen in hormone replacement therapy. Progestins are also used to treat secondary amenorrhea, dysfunctional uterine bleeding and endometriosis, and as palliative treatment of endometrial cancer, renal cell carcinoma, breast cancer, and prostate cancer. High-dose megestrol acetate is used to treat anorexia, cachexia, and AIDS-related wasting. Progesterone (or sometimes dydrogesterone or hydroxyprogesterone caproate) is used for luteal support in IVF protocols, questionably for treatment of recurrent pregnancy loss, and for prevention of preterm birth in pregnant women with a history of at least one spontaneous preterm birth. Progestins are also used in judicial chemical castration of sex offenders and in the treatment of individuals suffering from unwanted sexual urges (e.g., from hypersexuality, paraphilias, etc.). ==History== The recognition of progesterone's ability to suppress ovulation during pregnancy spawned a search for a similar hormone that could bypass the problems associated with administering progesterone (low bioavailability when administered orally and local irritation and pain when continually administered parenterally) and, at the same time, serve the purpose of controlling ovulation. The many synthetic hormones that resulted are known as progestins. The first orally active progestin, ethisterone (pregneninolone, 17α-ethynyltestosterone), the 17α-ethynyl analog of testosterone, synthesized in 1938 from dehydroandrosterone by adding acetylene either before or after oxidation of the 3-OH group to the ketone, with rearrangement of the 5,6 double bond to the 4,5 position, by Hans Herloff Inhoffen, Willy Logemann, Walter Hohlweg and Arthur Serini at Schering AG in Berlin, was marketed in Germany in 1939 as ''Proluton C'' and by Schering in the U.S. in 1945 as ''Pranone''. A more potent orally active progestin, norethisterone (norethindrone, 19-nor-17α-ethynyltestosterone), the 19-nor analog of ethisterone, synthesized in 1951 by Carl Djerassi, Luis Miramontes, and George Rosenkranz at Syntex in Mexico City, was marketed by Parke-Davis in the U.S. in 1957 as ''Norlutin'', and was used as the progestin in some of the first oral contraceptives (''Ortho-Novum'', ''Norinyl'', etc.) in the early 1960s.〔〔〔〔〔 Norethynodrel, an isomer of norethisterone, was synthesized in 1952 by Frank B. Colton at Searle in Skokie, Illinois and used as the progestin in ''Enovid'', marketed in the U.S. in 1957 and approved as the first oral contraceptive in 1960.〔〔〔〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Progestin」の詳細全文を読む スポンサード リンク
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