Estrogenic Substances

ESTROGENIC SUBSTANCES (from Greek oistros - passion, estrus), substances that cause processes in the female reproductive organs that form the normal sexual cycle. The main and most thoroughly studied of these substances is folliculin (also called feminin, menformon, thelykinin, theelin, teelol, progynon, hogival, estrin - various names usually associated with a proprietary preparation of one firm or another). It represents a hormone secreted by the follicles of the ovaries (see Sex hormones). Its main effect according to Zondek is the proliferation of the uterine mucosa, as well as the increase and strengthening of its musculature, preparing it for the reception of a fertilized egg and the development of the fetus; in addition, it stimulates the mammary glands into action (a question not fully clarified, since Cachiol and Lyons obtained milk from the mammary glands of heifers under the influence of the lactogenic hormone from the pituitary gland). The external manifestation of folliculin action in small animals consists of changes in the vagina, specifically the transformation of the mucous membrane, which can be easily established under a microscope in a vaginal smear and on which the 'folliculin test' proposed by Allen and Doisy and widely used is based, i.e., determining the strength of action of one or another folliculin preparation. The unit of this strength is the so-called 'mouse unit', ME (less commonly white rats are used for testing). It corresponds to the amount of folliculin that, when injected into a castrated mouse, causes in it under certain conditions the specified changes in the vagina. The changes caused in the uterus by folliculin constitute the first phase of the cycle, the 'proliferative' phase. After the egg leaves the follicle, a corpus luteum forms in its place (see), which secretes its own hormone ('corpus luteum hormone', progesterin, discovered in 1929 by Corner and Allen). The unit of this hormone is considered to be the amount sufficient to cause in the uterus of a rabbit under certain conditions such changes as normally occur at the beginning of pregnancy. According to Corner, the test is performed on a castrated rabbit, according to Klauberg - on a juvenile. The latter unit is four times smaller than the first. The secretion of both hormones in the body occurs under the influence of the secretion of the anterior pituitary gland (see). Aschheim and Zondek believe that the anterior pituitary gland secretes two gonadotropic (acting on the sex glands) hormones: A and B. The first stimulates the secretion of folliculin, the second - the corpus luteum hormone. This assertion is disputed by a number of authors. Clinical application of E.S. Experiments by Smith and Engle on monkeys showed that the administration of sufficient doses of folliculin, followed by the corpus luteum hormone, can cause a complete menstrual cycle in a castrated monkey. In 1932, Kaufmann in Berlin caused menstruation in 2 castrated women, which in duration and all other features did not differ from normal. These experiments made it possible to determine the normal dose of hormones needed to produce menstruation in a woman completely devoid of her own secretion of these hormones, and thus to proceed to their therapeutic use. According to Kaufmann, this normal dose is 200-300 thousand ME of follicular hormone and 30-50 KU (rabbit units according to Corner) of corpus luteum hormone. With such doses, Kaufmann succeeded in causing normal-type menstrual periods in women suffering from amenorrhea (see), including primary amenorrhea. He used a preparation of crystalline folliculin with benzoic acid. The preparation had a strength of 50,000 ME in 1 cm³. Injections were given in 4-6 doses with two-day intervals, after which, after 3 days, the corpus luteum hormone was injected daily at 10 KU (3-5 days). In some cases, after menstruation caused in this way, several spontaneous menstrual periods followed at normal or almost normal times, but not always. Kaufmann's results were confirmed by a number of authors. Werner, Jones and others used folliculin to treat involutional melancholia and report success. All these experiments have great prospective significance, but a number of questions remain unclear, especially the question of the effect of long-term hormone use, its effect on other glands (especially the pituitary), etc. Before widespread clinical use, comprehensive clinical testing is necessary. The chemical nature of E.S. is most clearly understood in relation to the follicular hormone, which was obtained by Doisy and almost simultaneously by Butenandt in chemically pure crystalline form as early as 1929. The success of Doisy and Butenandt was prepared, on the one hand, by the development of tests that allow continuous monitoring of chemical research by biological verification of their results, on the other hand, by the discovery of B. Zondek, showing that significant amounts of folliculin are present in the urine of pregnant women and mares. This urine is still the main raw material for obtaining folliculin. In 1 liter of urine from a pregnant mare there are up to 100,000 ME, from a pregnant woman - 10,000 ME. The reasons for the high content of folliculin in the urine of stallions (up to 40,000 ME in 1 liter) have not been clarified. Obtaining sufficient amounts of folliculin in chemically pure form allowed Butenandt to determine its chemical structure. Folliculin is an oxiketone, its formula is C₁₈H₂₂O₂. The most accepted structure is CH₃C However, folliculin is not the only substance that has the described specific effect. Cook and Dodds discovered (London, 1932) that a number of substances obtained from coal tar have the same effect, but to a lesser degree. Some of these substances also have a carcinogenic effect. Ergosterol and vitamin D, obtained from ergosterol under the influence of ultraviolet rays, also have estrogenic effect. All these substances are more or less related to each other chemically. In 1934, Cook, Dodds and Hewett succeeded in synthesizing a substance whose estrogenic strength is only 4 times less than that of α-folliculin. This is dipropyl anthraquinol. On the other hand, Schoeller and his collaborators succeeded in obtaining dihydrofolliculin, C₁₈H₂₄O₂, from folliculin by hydrogenation, which is several times stronger than α-folliculin. See table of the most important varieties of folliculin on p. 633-634. The corpus luteum hormone (progesterin, lutein hormone, luteosterone) has the formula C₂₁H₃₀O₂ (Butenandt and Westphal, almost simultaneously Slotta, Ruschig and others) and is a diketone. Its structure (II) is close to the structure of folliculin. Butenandt succeeded in synthesizing it from a variety of cholesterol - stigmasterol. It can be assumed that all sex hormones are formed in the body from cholesterol. The melting point, optical activity, and strength of the main varieties of folliculin are shown in the table. Ruzicka and his collaborators in 1934 obtained the male sex hormone, androsterone, C₁₉H₃₀O₂, from one of the two isomers of hydrogenated cholesterol (epidihydrocholesterol), which is similar in composition and structure to both female sex hormones. The possibility of obtaining androsterone from folliculin had been shown earlier by Schlenk and Bergmann and in 1934 confirmed by Dirschel and Voss. It has not yet been established whether androsteron has an estrogenic effect. The chemical relationship of the most important estrogenic substances, in particular the proper sex hormones, is revealed by the following comparison of their structural formulas: CH₃ CH₃-C-CH₂-CH₂ . - /\|/\ OH / CH₂-C-CH₂-CH₃| |__|^II | || oxidation /\/ \/

pregnandiol CH₃/CH/CH sterol or bile acid -CH₃ CH₃ __s_ CH₃] _.1 hormone of the corpus luteum CH I o CH₃ || /CH CH₃ | Li /CH folliculin androsteron The chemical nature of the pituitary hormone and its varieties obtained from urine remains still unclear. Action on plants. In 1931 and 1932, Scheller and Goebel showed that when added to the nutrient medium, folliculin accelerates the flowering of plants. Hyacinths bloomed 8 days earlier, calla lily gave two consecutive flowerings over a period of 4 months, while the controls barely gave one. The experiments of Scheller and Goebel were repeated by numerous researchers. Most obtained similar results, while others had negative results. Further experiments showed that additional conditions are necessary for a positive result. In any case, one cannot speak here of a specific influence of folliculin on the generative organs of the plant, but only of a general acceleration of growth: the same influence as folliculin was exerted on the plant by prolane, testiculin, prostatin and other hormones. The connection between estrogenic and carcinogenic action can be explained by the similarity of the basic biological process: in both cases, it is a matter of proliferation of tissue cells. In the sexual cycle, this proliferation is limited to certain tissues, harmoniously coordinated and has a positive biological meaning. In tumors, proliferation occurs chaotically, spreads to other organs (metastases) and is biologically negative. The connection between estrogenic and carcinogenic action is now established not only by the relationship of their chemical carriers, but also by physiological experiments. Reiss, Drukker and Hochwald established on 250 rats that removal of the pituitary slows down the growth of sarcomatous tumors, and sometimes leads to their disappearance; injection of folliculin weakens the growth of tumors and sometimes leads to their rapid disappearance. Wyeth established that in cancer patients the pituitary is enlarged compared to normal and this enlargement sometimes reaches 40%. All this allows us to assume that under certain conditions there is a distortion of endocrine activity, leading to biologically negative proliferation, i.e. to the formation or growth of tumors. The true nature of these phenomena still awaits clarification.--It should also be noted that a number of estrogenic substances are closely related to the so-called "organizers" or "evocators" - substances that determine the development of certain morphologically differentiated formations, in particular nervous tissue, in the still undifferentiated amphibian gastrula. These substances, described by Spemann and studied in regard to their chemical nature by Needham and his colleagues, could not only be obtained from natural organized material (various tissues), but in one case it was possible to obtain a typical effect with the use of a synthetic preparation.