Antagonism relaxations

ANPs play an important role in the maintenance of cardiovascular homeostasis by counterbalancing the renin—angiotensin (RAS) system. ANP, the main circulating form of the natriuretic peptides, effectively relaxes vascular smooth muscle, promotes the excretion of sodium and water, and in the CNS inhibits vasopressin release and antagonizes AT-II induced thirst. 

Neostigmine will effectively antagonize skeletal muscle relaxation produced by... 

Chan Y, Leung F, Yao X, Lau C, Vanhoutte PM, Huang Y (2004) Raloxifene relaxes rat pulmonary arteries and veins roles of gender, endothelium and antagonism of Ca2+ influx. J Pharmacol Exp Therap... 

Adrenergic Beta 1 receptor ADRBl Agonism May stimulate cardiac muscle (increase heart rate and force of contraction) and contributes to the relaxation of blood vessels. Antagonism May stress cardiovascular performance. 

Dicyclomine (Bentyl), oxybutynin (Ditropan), and tolterodine (Detrol) are nonselective smooth muscle re-laxants that produce relatively little antagonism of muscarinic receptors at therapeutic concentrations. The mechanism of relaxation is not known. Finally, some other classes of drugs can act in part as muscarinic antagonists. For example, the antipsychotics and antidepressants produce antimuscarinic side effects (e.g., dry mouth). 

Smooth muscle relaxation, central nervous system (CNS) excitation, and cardiac stimulation are the principal pharmacological effects observed in patients treated with theophylline. The action of theophylline on the respiratory system is easily seen in the asthmatic by the resolution of obstruction and improvement in pulmonary function. Other mechanisms that may contribute to the action of theophylline in asthma include antagonism of adenosine, inhibition of mediator release, increased sympathetic activity, alteration in immune cell function, and reduction in respiratory muscle fatigue. Theophylline also may exert an antiinflammatory effect through its ability to modulate inflammatory mediator release and immune cell function. 

Mirakhur RK. Antagonism of neuromuscular block. Bailliere s Clin Anaesthesiol 1994 8 461-81. Mirakhur RK, McCoy EP. The new relaxants. Curr Opin Anaestiiesiol 1994 7 365-9. 

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