True endocrine hormone

True endocrine hormones, however, remain a fairly well defined group. Virtually all of the hormones used therapeutically (discussed below) fit into this grouping. Examples include insulin, glucagon, GH and the gonadotrophins. 

Female sexual development and behaviour in mammals occurs by default and requires no ovarian secretion, and it is only in genetic males that the testis can secrete hormones which destroy this female pattern and superimpose that of the male. Sexual differentiation is not so well defined in fish, and larval exposure to both synthetic estrogens and androgens is widely used in aquaculture to produce monosex cultures. Endocrine disruption of sexual differentiation in fish may therefore reflect both the complexity and diversity of such processes between different species. Some care is required in use of the terms hermaphrodite and sex-reversal since a true hermaphrodite has both functional testes and ovaries and a sex-reversed fish is fully functional as its final sex—both produce the appropriate viable gametes. Such functional sex-reversal is not possible in mammals, but in some species of fish it is the normal developmental pattern. In most of the cases of hermaphroditism or sex-reversal reported in the non-scientific press, there is evidence only for a few ovarian follicles within a functional testis. This may be considered as feminisation or a form of intersex, and is very clearly endocrine disruption, but it is certainly neither sex-reversal nor hermaphroditism. In some cases the terms have even been used to infer induction of a single female characteristic such as production of yolk-protein by males. 

There are no well-defined clinical characteristics or established tests to identify patients likely to benefit from chemotherapy. Factors associated with an increased probability of response that have been identified include a good performance status, a limited number (one to two) of disease sites, and patients who respond to chemotherapy or hormonal therapy with a long disease-free interval. Patients who have progressive disease during chemotherapy have a lower probability of response to a different type of chemotherapy. However, this is not necessarily true for patients who are given chemotherapy after some interval during which they have received no chemotherapy. Patients who do not respond to endocrine therapy are as likely to respond to chemotherapy as patients who are treated with chemotherapy as their initial treatment modality. Age, menopausal status, and receptor status have not been associated with favorable or unfavorable response to chemotherapy. 

However, even such distinguishing characteristics have become blurred. EPO, for example, is produced in the kidney and liver and acts in an endocrine manner, promoting production of red blood cells in the bone marrow. EPO could thus also be considered to be a true hormone. 

The lowered detection limits of the newer two-site immunoassays for the measurement of pituitary hormones now make it possible to distinguish an abnormally low value from the lower end of the normal reference interval. Although assessment of a particular aspect of pituitary function should also include clinical signs and symptoms of hormone deficiency and the measurement of hormones secreted by the pertinent endocrine gland (e.g., T4, cortisol, and testosterone), the newer, ultrasensitive assays for TSH, FSH, LH, and ACTH allow for an accurate distinction of a true low result from low normal. A scheme for testing of pituitary reserve is fisted in Box 50-6. 

In humans and other higher-level animals, emotions are thought to arise in the brain, but that is not quite true. The nervous system connects the entire body, and the endocrine system of glands secretes hormones that circulate through the entire body. Because of this, tissue and organ BU are washed in biochanicals, and subject to the effects of anotion as is the entire organism. 

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