Male sex hormones

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 ... 

FIGURE 25.43 The steroid hormones are synthesized from cholesterol, with intermediate formation of pregnenolone and progesterone. Testosterone, the principal male sex hormone steroid, is a precursor to /3-estradiol. Cortisol, a glucocorticoid, and aldosterone, a mineralocorticoid, are also derived from progesterone. 

The metabolic rate is increased by several hormones including thyi oid hormone, adrenalin and male sex hormones. The increase in metabolic rate caused by male sex hormones explains why males have slightly higher average metabolic rates than females of the same size and age. Living in a cold climate increases the metabolic rate because the cold stimulates thyroid hormone production and this hormone increases heat output of the body, while living in a warm climate causes the metabolic rate to decrease. 

The male sex hormone testosterone contains C, H, and O and has a mass of 288.2089 amu as determined by high-resolution mass spectrometry. What is the likely molecular formula of testosterone ... 

Sex Hormones Testosterone and androsterone are the two most important male sex hormones, or androgens. Androgens are responsible for the development of male secondary sex characteristics during puberty and for promoting tissue and muscle growth. Both are synthesized in the testes from cholesterol. Androstenedione is another minor hormone that has received particular attention because of its use by prominent athletes. 

Androgens, represented by testosterone, are male sex hormones involved in reproduction, behavior, and bone and muscle growth. 

The chemical formula of a compound represents its composition in terms of chemical symbols. Subscripts show the numbers of atoms of each element present in the smallest unit that is representative of the compound. For molecular compounds, it is common to give the molecular formula, a chemical formula that shows how many atoms of each type of element are present in a single molecule of the compound. For instance, the molecular formula for water is H20 each molecule contains one O atom and two H atoms. The molecular formula for estrone, a female sex hormone, is Clgl-I2202, showing that a single molecule of estrone consists of 18 C atoms, 22 FI atoms, and 2 O atoms. A molecule of a male sex hormone, testosterone, differs by only a few atoms its molecular formula is (lyH2802. Think of the consequences of that tiny difference ... 

In addition, it has been suggested that short-term exposure to phytoestrogens during adulthood does not affect male sex hormone concentrations or semen quality (Mitchell et al, 2001). 

Anabolic steroids Corticosteroids Male sex hormones Female sex hormones Oral fertility agents... 

Androgens are male sex hormones testosterone and dihydrotestosterone are good examples ... 

The follicular phase covers the development of the follicle, which involves an increase in its size due to an increase in follicular fluid, growth of the ovum (i.e. an increase in the contents of RNA and protein) and an increase in the number of cells that surround the ovum. These cells are of two types, the granulosa and the thecal cells. The role of these cells is to synthesise and secrete the steroid hormones oestrogens (mainly oestradiol). The precursor molecule for their synthesis is cholesterol. There is a division of labour between these cells the thecal cells convert cholesterol into the male sex hormones androstenedione and testosterone, which are released into the blood to be taken up by the granulosa cells where they are converted to the oestrogens (Figure 19.8). For details of pathways, see Appendix 19.1. 

This annulation process was of considerable value in early approaches to steroid synthesis. The structural relationship of the bicyclic product obtained here to the male sex hormone testosterone is immediately apparent. Further, the non-conjugated carbonyl is now activating the adjacent carbon that subsequently features in building up the third ring system. 

Of the numerous hormones that regulate body function, two steroid hormones are extremely important estradiol, a female sex hormone and testosterone, a male sex hormone. Present in the body in insignificant amounts, they regulate sexual differentiation and reproduction as well as affect the performance of many other physiological systems. Despite the great similarity in chemical structure, they are very different in terms of physiological action. 

Steroids that possess angular methyl groups at both the 10 and 13 positions but which are devoid of acetyl side chains at the 17 position are usually classed as derivatives of the hypothetical hydrocarbon, androstane. The endogenous male sex hormones, such as, for example, testosterone, can all be classified as androstanes as will be noted below, the biological activity of compounds in this stmctural class goes beyond that narrow definition. 

Sex hormones control tissue growth and reproduction. Male sex hormones are testosterone and Sa-dibydrotestosterone, also known as androgens, which are secreted by the testes. The primary male hormone, testosterone, is responsible for the development of secondary sex characteristics during puberty. They also promote muscle growth. The two most important female sex hormones are oestradiol and oestrone, also known as oestrogem estrogens). They are responsible for the development of female secondary sex characteristics. 

Sharpe suggested that DDE (which inhibits male sex hormones—androgens—and is an antiandrogen ) may play a role in the hypothesized increases in diseases or problems in the male reproductive tract35 However, breast-milk levels of DDE (a commonly used measure for DDE exposures) are comparable in all four Scandinavian countries and therefore do not correlate with... 

---