[Bronchial asthma and the beta adrenergic system].

The relationship between bronchial asthma and the beta adrenergic system is considered both from the physiopathologic and therapeutic point of view. A brief analysis of the sympathetic system is performed. The sympathetic nervous system is responsible for bronchodilation mediated through its beta-receptors. To evaluate this activity, beta adrenergic blockers such as propanolol are used. When this agent is administered, a descent of conductance is observed. On this condition, vagal stimulation brings about bronchoconstriction. At bronchial level, it seems that the beta-adrenergic system antagonizes vagal effect. From the physiopathologic point of view, Szentivanyi (1968) suggested a spontaneous beta block in the asthmatic. Other theories refer to a pathologic sensitivity of the peripheral bronchial receptors. The natural beta-adrenergics and the beta-adrenergic drugs enhance the synthesis of cAMP by stimulating the adenil cyclase system. This effect brings about relaxation of the bronchial smooth muscle. Considering the therapeutic effects, a comparative study of bronchodilators is performed. From all, Salbutamol has an intense broncholytic effect with little effect on heart dynamics. When sympathomimetics are bound to use in asthma, drugs such as Salbutamol and Terbutalina should be preferred because of its low cardiogenic effects. Its administration per os has rendered doubtful results.