0-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). 

Because of the widespread nature of adrenoceptors, nonselective P-agonists can produce many undesirable side effects. Therefore, before adrenergic agonists could become widely used in the treatment of asthma, some selectivity in action was needed. Whereas epinephrine and ephedrine have significant agonist activity at both a and P adrenoceptors, isoproterenol is a selective agonist at the P receptor (39). However, isoproterenol does not distinguish between the P and receptors and it is not active orally. 

A common strategy for treating chronic opiate addiction iavolves the substitution of methadone which can either be provided as maintenance therapy or tapered until abstinence is achieved. Naltrexone and buprenorphine [52485-79-7] have also been used ia this manner. The a2 adrenergic agonist clonidine [4205-90-7] provides some rehef from the symptoms of opiate withdrawal, probably the result of its mimicking the inhibitory effect of opiates on the activity of locus coerukus neurons. 

A special feature of the iris is its autonomic innervation. Sympathetic activation widens the aperture of the iris whereas impulses from the parasympa thetic nervous system decrease the aperture size. Therefore adrenergic agonists and anticholinergic compounds both increase the aperture of the iris, i.e., cause mydriasis, and antiadrenergic and cholinergic agonists decrease it, i.e., cause miosis. The iris can thus be considered an excellent mirror reflecting the balance of the autonomic nervous system in the body. " ... 

As noted above, g-adrenergic agonists such as epinephrine typically cause relaxation of smooth muscle. This agent... 

Prenalterol (73) interestingly exhibits adrenergic agonist activity in spite of an interposed oxymethylene... 

Beta adrenergic agonists also exert bronchodilating effects. These drugs are thus often used in conjunction with theophiline in asthma therapy. A drug that combines both moieties, reproterol (40), has interestingly proved... 

A compound closely related to classical adrenergic agonists in which the para hydroxy function is however replaced by an amino group has been investigated for its activity as a growth promoter in domestic animals. Acylation of the aniline derivative 26 with chloracetyl chloride will afford acetophenone 27 the amino-ketone 28 is obtained on reaction with isopropylamine. Removal of the protecting group (29) followed by reduction of the ketone affords cimaterol (30) 5J. 

The imidazoline receptor is a hypothetical receptor for a subgroup of a2 adrenergic agonists, which are characterized by their imidazoline structure (e.g. moxoni-dine). So far, there is no proof of the existence of imidazoline receptors. 

It is not surprising that intramuscular injection of epinephrine into the vastus lateralis produces a prompt peak plasma epinephrine concentration, because of the large size and excellent vascularization of this muscle. It is also not surprising that subcutaneous injection of epinephrine potentially leads to delayed absorption, because of the potent Ui-adrenergic agonist vasoconstrictor effects in the skin and subcutaneous tissue, as evidenced by skin blanching at the injection site [19, 20]. 

Westfall TC, Westfall DP Adrenergic agonists and antagonists in Brunton LL, Lazo JS, Parker KL (eds) Goodman Gilman s The Pharmacological Basis of Therapeutics, ed 11. New York, McGraw-Hill, 2006, pp 237-247. 

Figure 3 Structures of phenethanolamine /3-adrenergic agonists of potential human food safety concern. Multi-residue methods have been developed with the goal of broad cross-reactivity so that simultaneous screening may occur efforts have not been particularly successful...

Systemic corticosteroids if no immediate response or incomplete response to aggressive inhaled P2-adrenergic agonist therapy, if patient recently received an oral corticosteroid, or if the episode is considered severe... 

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