Hormones, sex

In summary, although many sex hormone products have their greatest therapeutic uses in either women or men. nearly all have. some u.ses in both sexes. Nevertheless, the higher concentrations of estrogens and progesterone in women and of te.stostcrone in men cause the development of the complementary reproductive systems and charactcri.stic physical differences of women and men. 

The active endogenous estrogens are e.stradiol. estrone, and estriol. Estradiol provides the greatest estntgenic activity. 

The estrogens also stimulate the development of lipid and other tissues that contribute to breast shape and function. Pituitary hormones and other hormones ate also involved. Fluid retention in the brea.sts during the later stages of the menstrual cycle is a common effect of the estrogens. 

The physiological changes at menopause emphasize the imponant roles of estrogens in the young woman. Breast and reproductive tissues atrophy, the skin loses some of its supplenc.ss. coronary atherosclerosis and gout become potential health problems for the flrst time, and the bones begin to lose density becau.se of decrea.scd mineral content. 

Diethylstllbestrol Derivatives. At flrst glance, it inighi be surprising that non.stcroidaI molecules such as diethylslil- 

However, the sex-hormones belong to the steroid class of compoimds and are produced in the gonads, i.e., testes in the male and ovaries in the female. In fact, their activity seems to be controlled and monitored by the hormones that are produeed in the anterior lobe of the pituitary glands. Perhaps beeause of this inherent characteristies the sex hormones are invariably termed as the secondary sex hormones and the hormones of the anterior lobe of the pituitary are called the primary sex-hormones. 

A general survey of the literature stretching over the past three decades would reveal that a vast number of structural modifications of the steroid hormones have taken place. These newer compormds have been prepared with a view to enhanee their biological activities, oral activity and drrration of action, besides attributing better solubility properties, minimising the requirement for some essential perimeter funetional group of the parent hormone and lastly to effect a marked separation of their biologieal activities. 

Sex-hormones are usually elassified imder the following three heads, namely  

In females there are two successive proliferations of the sexual cords. The first proliferation produces buds resembling those that develop in males and yield rudimentary seminiferous tubules but no interstitial cells. This first attempt to produce a germinal gland is abortive, and the rudiments become the medullary cords. The second proliferation of the germinal epithelium leads to the formation of the cord of Pfliiger. Inside these tubules are gonocytes that do not proliferate actively but increase in size, and even in the embryo they resemble ovocytes. 

The adult ovary has a superficial epithelium resting on a thick layer of connective tissue that contains follicles at various stages of development. This cortical zone of the ovary surrounds a fibrous medullary part that contains no follicles but contains arterioles, venules, lymphatics, and the cellular cords which appeared during the first proliferation of the germinal epithelium. 

Three or four hours after the follicular rupture, the follicle is replaced by the corpus luteum, a small structure measuring 1-2 cm in diameter. The corpus luteum is yellowish because the cells contain large amounts of lipid, and it often contains a central clot due to hemorrhage. The corpus luteum disappears after 2 weeks in the absence of pregnancy, but it remains well developed throughout pregnancy. 

Details of follicular formation and ovulation remain unsettled. There is some indication that the liquor is formed by filtration of plasma rather than as a result of venous or lymphatic obstruction. Increased hydrostatic pressure in the follicle is unlikely to cause its rupture. Rupture seems to result from focal alteration of the site of the stigma. Electron microscopic examination of the stimaga reveals collagen digestion and cell separation. 

A look at the metabolic map reveals that there are two major pathways for estrogen synthesis, one involves progesterone as an intermediate, and the other bypasses the isomerization. The relative activities of the pathway (progesterone) and of the A pathway (pregnenolone) can be compared by studying the fate of labeled progesterone with that of labeled pregnenolone [71]. 

Male Aphomia sociella L, the bumble bee waxmoth, contains a sex pheromone in its wing gland, the major part of which is an R(-)mellein (= ochracin). The compound, which evokes searching behavior in females, is produced by a mold, Aspergillus ochraceus, found in the intestine of the last-instar larvae and in the bumble bee nest [180]. Apparently such insect-fungus relationships are widespread. 

Substances IA Ib and Ic are peptidic sexual agglutination factors of Saccharo-myces cerevisiae [181]. Rhodotorucine A is a peptide produced by type A cells of Rhodospridium toruloides which induces mating tube formation in yeast of mating type a [182]. A bacterial sex pheromone, called cPDl, has been isolated from Streptococcus faecalis. Its structure is phe-leu-val-met-phe-leu-ser-gly [183]. Competence in Streptococcus pneumoniae is induced by a heptadecapeptide, H-Glu-Met-Arg-Leu-Ser-Lys-Phe-Phe-Arg-Asp-Phe-Ile-Leu-Glu-Arg-Lys-Lys-OH which is destroyed by a protease [184]. 

Microbial secondary metabolites can exert regulation of cellular activities in higher organisms [ 185]. It has been hypothesized that cell-to-cell communication first evolved in unicellular organisms, long before the appearance of specialized 

Kirk-Othmer Encyclopedia of Chemical Technology (4th Edition) 

Extracts of corpora lutea were known ia the early tweatieth ceatury to inhibit ovulatioa ia animals. Pure progesterone (3), the active component of the extracts, was isolated ia 1934 and its stmcture reported (15). Several problems limited its use and drove efforts to develop progesterone analogues, ie, it was available only ia small quantities from animal sources, was not orally active, and was discovered to cause androgenic side effects. 

Eirst degradation process used to produce progesterone. 

Methods for reconstmcting the C-17 side chain from intermediates such as androstendione have been developed. These are used when commercial considerations favor the production of androstanes, but pregnanes are the ultimate goal (25,30). 

The primary support for a hormonal influence in adult neurogenesis comes from the reports of neural progenitor cell 

Nerve grow th factor (NGF) is required for survival and neurite outgrow th of cholinergic neurons of the basal forebrain. 

The increased number of new ly generated cells in the SGZ follow ing hfe-style modulators, is thought to be due to the increase in cell survival and has been linked to increased protein levels for both BDNF and neurotrophin 3 (NT-3) (Lee et al., 2000, 2002 Duan et al., 2001). Ciliary neurotrophic factor (CNTF) is an acidic protein involved in type-2 astrocyte differentiation. Injection of CNTF into the mouse brain stimulates precursor cell proliferation w ith the CNTF receptor alpha expressed on GFAP-positive cells of the SVZ (Fmsley and Hagg, 2003). 

The 17/3-estradiol-induced increase in NOS activity was accompanied by increased levels of NOS mRNA, suggesting that estrogen exerts its effects at the transcriptional level and can, in effect, induce the Ca -dependent NOS in endothelial cells. As yet, the process by which induction occurs has not been elucidated, and although it is frequently supposed that the NOS promoter contains an estrogen-responsive element, sequence analysis of the human endothelial NOS has failed to identify such an element Marsdcn et al., 1993). 

Sex hormones may have other effects that influence vascular reactivity independent of NO formation. For example, 17j8-estradiol also attenuates 

The in vivo conversion of cholesterol to esterone in man has been demonstrated (Webbin et al., 1957) and Rabinowitz (1957) has shown that preparations of testicular tissue may convert cholesterol directly into estradiol. Baggett et al. 

17x-HydroxypregnetwUme Dehydroepiandrosterone A -Andro tene-3-17-Dione Testosterone 

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An oestrogen present in the urine of pregnant women. It possesses female sex hormone activity but is not as active as oestrone. 

Grandisol, with a four-membered ring, is another insect hormone, the male sex hormone of the boll weevil to be precise. It may also be useful as a highly specific pest control. How might it be made ... 

R B Woodward was one of the leading organic chemists of the middle part of the twenti eth century Known pnmanly for his achievements in the synthesis of complex natural products he was awarded the Nobel Pnze in chemistry in 1965 He entered Massachusetts Institute of Tech nology as a 16 year old freshman in 1933 and four years later was awarded the Ph D While a student there he earned out a synthesis of estrone a female sex hormone The early stages of Woodward s estrone synthesis required the conversion of m methoxybenzaldehyde to m methoxy benzyl cyanide which was accomplished in three steps... 

As we have seen in this chapter steroids have a number of functions in human physiology Cholesterol is a component part of cell mem branes and is found in large amounts in the brain Derivatives of cholic acid assist the digestion of fats in the small intestine Cortisone and its derivatives are involved in maintaining the electrolyte balance in body fluids The sex hormones responsible for mascu line and feminine characteristics as well as numerous aspects of pregnancy from conception to birth are steroids... 

Testosterone promotes muscle growth deepening of the voice the growth of body hair and other male secondary sex characteristics Testosterone is formed from cholesterol and IS the biosynthetic precursor of estradiol the principal female sex hormone or estrogen Estradiol is a key substance m the regulation of the menstrual cycle and the reproductive process It is the hormone most responsible for the development of female secondary sex characteristics... 

Cholesterol (Section 26 11) The most abundant steroid in am mals and the biological precursor to other naturally occur ring steroids including the bile acids sex hormones and corticosteroids... 

Estrogen (Section 26 15) A female sex hormone Ethene (Section 5 1) lUPAC name for H2C=CH2 The com mon name ethylene however is used far more often and the lUPAC rules permit its use... 

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