Hormones catecholamines

Discuss functions and factors regulating release of the following hormones thyroid hormones, calcitonin, parathyroid hormone, catecholamines, aldosterone, cortisol, adrenal androgens, insulin, and glucagon... 

Feature Steroid hormones Protein/peptide hormones Amine hormones Thyroid hormones Catecholamines ... 

Amino acid derivatives include the thyroid hormones, catecholamines (e.g. adrenaline (epinephrine)) and dopamine, neurotransmitters such as y-aminobutyric acid (GABA) and noradrenaline (norepinephrine). All of these signalling molecules retain... 

Other components of the urine are conjugates with sulfuric acid, glucuronic acid, glycine, and other polar compounds that are synthesized in the liver by biotransformation (see p. 316). In addition, metabolites of many hormones (catecholamines, steroids, serotonin) also appear in the urine and can provide information about hormone production. The proteohormone chorionic gonadotropin (hCG, mass ca. 36 kDa), which is formed at the onset of pregnancy, appears in the urine due to its relatively small size. Evidence of hCG in the urine provides the basis for an immunological pregnancy test. 

Catecholamines produced in the brain and in other neural tissues function as neurotransmitters, but epinephrine and norepinephrine are also hormones, synthesized and secreted by the adrenal glands. Like the peptide hormones, catecholamines are highly concentrated within secretory vesicles and released by exocytosis, and they act through surface receptors to generate intracellular second messengers. They mediate a wide variety of physiological responses to acute stress (see Table 23-6). 

Wilson BE, Hobbs WN. Case report pseudoephedrine-associated thyroid storm thyroid hormone—catecholamine interactions. Am J Med Sci 1993 306(5) 317-9. 

Surface Membrane Receptors. These receptors are located on the outer surface of the plasma membrane (see Fig. 28—2).6 Surface receptors tend to recognize the peptide hormones and some amino acid derivatives (e.g., pituitary hormones, catecholamines). They are typically linked to specific intracellular enzymes. When stimulated by a peptidelike hormone,... 

Murray and coauthors (Murray et al. 2001) claim that corticotropin-releasing hormones, catecholamines, neuropeptides, and steroid hormones produced throughout the central nervous system as well as in several peripheral sites including the pituitary, testes, ovaries, heart, adrenals, and immune tissues play an important role in the immunomodulatory mechanism of stress affecting human or animal bodies. 

Because capillary walls are thin (to permit diffusion) the blood that is delivered to them must be delivered under reduced pressure. This is accomplished by the arterioles, which combine relatively muscular walls with a narrow lumen. The arterial blood pressure is a function of cardiac output and the total peripheral vascular resistance, which is primarily a function of the degree of normal tension (tonus) of the smooth muscle cells in the walls of the arterioles. If this tonus increases above the normal range for extended periods of time, hypertension (high blood pressure) will result. This tonus is under the control of the autonomic nervous system and of adrenergic hormones (catecholamines). 

Flavonoids are widely distributed in fruits and vegetables and are very common nutritional supplements as antioxidants. The results on antioxidant activities of simple catechols provide a useful basis for evaluating results for the many, more complex natural compounds containing the catechol structure, such as the flavonoids, steroidal catechols and hormonal catecholamines. There are several reviews on the antioxidant properties of flavonoids and several reports on experimental " and theoretical evidence linking their antioxidant properties to the catechol moiety usually found in their structure. The basic flavonoid structure (29) is shown in Chart 1, with a few selected examples (30-36) from different groups to illustrate some of the relationships between their detailed structures and related antioxidant properties. Efforts to elucidate these relationships are hampered by their very low solubility in non-polar solvents, and the tendency of some researchers to employ metal ions as initiators of oxidation in aqueous media so that one cannot distinguish between their action as chain-breaking... 

Prolonged treatment with glucocorticoid hormones can cause calciuria. Furthermore, insulin, glucagon, growth hormone, thyroid hormone, catecholamines, and angiotensin have been reported to increase urinary calcium excretion while estrogen causes a decreased urinary calcium excretion. Antidiuretic hormones may cause increased excretion depending on other factors. 

Biogenic amines are a group of aliphatic, aromatic or heterocychc bases derived from amino acids, which exhibit a variety of biological effects, as they perform different functions in animal and plant tissues. Some biogenic amines are building materials for the biosynthesis of phytohormones of the auxin group, plant protoalkaloids (such as hordenine and gramine), true alkaloids and other secondary plant metabolites. In animal tissues they have the function of tissue hormones (e.g. histamine) and are precursors of adrenal hormones (catecholamines). 

Tryptamine Tryptophan Serotonine, melatonine Locan tissue animal and plant hormones (catecholamines), effect on blood pressure, intestinal peristalsis, mental functions... 

It seems likely that the metabolic effects of several hormones are mediated by adenosine 3, 5 -phosphate (cyclic AMP). The biochemical effects of this nucleotide have been discussed. 3-92 Cyclic AMP is synthesized from ATP by a reaction catalyzed by adenyl cyclase and it is rapidly inactivated by a cyclic 3, 5 -nucleotide phosphodiesterase which converts it to 5 -AMP.91 Cyclic AMP levels are Influenced by numerous hormones, (catecholamines, glucagon, ACTH, Insulin, and others).91 Most of these stimulate adenyl cyclase and Increase cyclic AMP levels, however, insulin... 

These criteria have been fulfilled for many polypeptide hormones, catecholamines, and certain neurotransmitters. Thus, it is clear that the mechanism of action of a large number of extracellular signal molecules occurs via the adenylate cyclase-cAMP system, by first binding to a membrane receptor. As is pointed out by Sutherland (Robison et al., 1971), the major problems remaining are to determine the molecular events whereby a specific hormone activates adenylate cyclase to generate cAMP, and to determine how cAMP mediates the various physiological functions attributed to the specific hormones. 

The demand for the consumption of fuel reserves can be regarded as a form of metabolic stress. This is characterized by a low activity of insulin relative to stress hormones catecholamines, corticotropin, glucocorticoids and glucagon. Such an hormonal balance can occur in starvation, diabetes, trauma and under the influence of certain toxins. As we have seen earlier, it can also be a response to the ingestion of large amounts of ethanol, fructose or fat. 

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