Natural and synthetic hormones

Thyroid hormones used in medicine include both the natural and synthetic hormones. The synthetic hormones are generally preferred because they are more uniform in potency than are the natural hormones obtained from animals. Thyroid hormones are listed in the Summary Drug Table Thyroid and Antithyroid Dragp. 

After exerting their action in the organism, natural and synthetic hormones are catabolized in the liver by conjugation to glucuronide and/or sulfate moieties, forming more polar conjugated forms which are excreted via urine. This is the main route of hormone excretion in humans and pigs. A fraction of hormones is also excreted in a free form via feces in animals such as sheep and cattle this is the main route for hormone excretion (Table 3) [66, 67],... 

The list of new chemicals whose presence in the environment represents an ascertained or potential risk is sizeable and broadly contains resins, plastics, and plastic additives (e.g., plasticizers and flame retardants) pharmaceuticals and personal care products (e.g., disinfectants, fragrances, sunscreens, antibiotics, drugs of abuse, and natural and synthetic hormones) detergents and other cleaning... 

The heptafluorobutyrate derivative was selected for gas chromatographic separation, using electron capture detector (ECD), in order to enable the detection of ultramicro quantities43. The interest in the analysis of natural and synthetic hormones in very small concentrations enhanced the development of the GC method, in comparison with the UV study.44... 

Substances such as promoters that interfere with cell-to-cell communication allow cancer cells to proliferate wildly. But cell proliferation can be induced by other means as well. Toxicity or other types of injury to tissues can result in a proliferative response. So can certain natural and synthetic hormones, such as estrogens, cause proliferation of certain tissues, such as the breast. Chronic viral infections may cause cell killing and its consequence is cell proliferation. It appears that sustained chronic proliferation induced in any of these ways, either by agents foreign to the body or some, such as the estrogens, that are natural to it, can increase tumor growth. 

The decreased level of androgens in castrated male cattle as a result of testicular removal leads to production of a carcass that is intermediate between that of an intact male and a female. Since the increased proportion of fat in such a carcass makes it less valuable for the health-conscious consumer, extensive research has been directed towards replacing the loss of carcass quality resulting from castration, by administration to the animals of various natural and synthetic hormonal substances, collectively called anabolic hormonal-type growth promoters. These compounds can substantially increase growth rate and improve feed efficiency and carcass composition in a process that may be highly profitable for the animal feeders. 

Barel-Cohen, K., L.S. Shore, M. Shemesh, et al. 2006. Monitoring of natural and synthetic hormone in polluted river. J. Environ. Manage. 78 16-23. 

Natural and synthetic hormones are used worldwide to improve meat production There are, however, possible hazards for the consumer. Therefore, in most European countries the use of hormonal anabolics is restricted or even prohibited by law. Among the banned synthetic anabolics diethylstilbestrol (DES) takes the most important place at the moment. Analytical control is carried out in various ways. Frisch-kom and Smyth have described an HPLC method with electrochemical detection for the determination of growth promoting hormones in meat. 

Most water treatment plants are not prepared to remove pharmaceuticals, including natural and synthetic hormones, that are flushed down the sink or toilet. Those that use chemical oxidative processes to remove estrogens and other medications generate disinfection by-products in the water supply that pose potential risks to human health. Some communities organize collections of unused or unwanted over-the-counter and prescription medications for disposal by authorized incineration. 

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