P-Adrenergic agonist

Somatotropin, the P-adrenergic agonists, and the anaboHc steroids are considered metaboHsm modifiers because these compounds alter protein, Hpid, carbohydrate, mineral metaboHsm, or combinations of these and they partition nutrient use toward greater rates of protein deposition, ie, muscle growth, and lesser rates of Hpid accretion. Historical data leading to understanding of the mechanism (s) of action are found in reviews on anaboHc steroids (1), somatotropin (2—4), and the phenethano1 amines (5—7). 

Epinephrine is a nonspecific a- and P-adrenergic agonist. Epinephrine can increase cardiac index and produce significant peripheral vasoconstriction. However, it can also increase lactate levels and impair blood flow to the splanchnic system. Because of these undesirable effects, epinephrine should be reserved for patients who fail to respond to traditional therapies.24,27-28... 

As noted above, phenylethanolamines are usually p-adrenergic agonists, whereas phenylpropanolamines show antagonist activity. A small series of phenyl-ethanolamine blockers is, however, known. When the haloatom of u)-bromo-5,6,7,8-tetrahydro-2-acetonaphth-one (36) is displaced with isopropylamine and the... 

The use of p-adrenergic agonists as broncho-dilators is discussed in some detail in Chapter 3. 

Adrenalin, chloroacetyl chloride in production of, 7 142 P-Adrenergic agonists as animal growth regulators, 73 14-17 genotype, gender, and nutritional interactions related to, 73 16 mechanism of action of, 73 17 Adrenergic neuronal blockers,... 

Derivatives of phenylethanolamine substituted by a phenolic hydroxyl on the para position have been known for some time to exhibit p-adrenergic agonist activity. As a consequence of this property, the compounds have proven useful as bronchodilators for the treatment of asthma (see Chapter 3). Since such sympathomimetic drugs tend to have undesired activity on the cardiovascular system in addition to the desired activity on the bronchii, considerable work has been devoted to the preparation of compounds that would show selectivity for the adrenergic receptors (P2) that predominate in the lung. Attachment of the side chain to a heterocyclic aromatic phenol has been one avenue that has shown promise for achieving this selectivity. 

Based on the concept that asthma is an inflammatory disease that leads to airway obstruction, inhaled glucocorticoids are the first-line treatment for moderate to severe asthma. Inhaled preparations are particularly effective when used to prevent recurrent attacks. This therapy is often combined with an inhaled bron-chodUator such as a p-adrenergic agonist. The use of p-adrenergic agonists or theophylline enables use of a lower dose of glucocorticoid, especially in patients relatively resistant to therapy (see Chapter 39). 

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