Secretin
Secretin was the first hormone to be identified. In 1902, William Bayliss and Ernest Starling were studying how the nervous system controls the process of digestion. It was known that the pancreas secreted digestive juices in response to the passage of food (chyme) through the pyloric sphincter into the duodenum. They discovered (by cutting all the nerves to the pancreas in their experimental animals) that this process was not, in fact, governed by the nervous system. They determined that a substance secreted by the intestinal lining stimulates the pancreas after being transported via the bloodstream. They named this intestinal secretion "secretin". Secretin was the first such "chemical messenger" identified. This type of substance is now called a hormone, a term coined by Bayliss in 1905.
Ethisterone
Ethisterone, also known as ethinyltestosterone, pregneninolone, and anhydrohydroxyprogesterone and formerly sold under the brand names Proluton C and Pranone among others, is a progestin medication which was used in the treatment of gynecological disorders but is now no longer available. It was used alone and was not formulated in combination with an estrogen. The medication is taken by mouth.
Side effects of ethisterone include masculinization among others. Ethisterone is a progestin, or a synthetic progestogen, and hence is an agonist of the progesterone receptor, the biological target of progestogens like progesterone. It has some androgenic and anabolic activity and no other important hormonal activity.
Ethisterone was discovered in 1938 and was introduced for medical use in Germany in 1939 and in the United States in 1945. It was the second progestogen to be marketed, following injected progesterone in 1934, and was both the first orally active progestogen and the first progestin to be introduced. Ethisterone was followed by the improved and much more widely used and known progestin norethisterone in 1957.