<prompt> Mechanism of action of aminophylline in bronchial asthma:Decreasing phosphodiesterase activityDirect action on smooth musclesReleasing catecholaminesStabilizing membrane of mast cells  <response>: Aminophylline and other methylxanthines act byInhibiting phosphodiesterase enzyme causing - cAMPBlocking adenosine receptorsReleasing Ca2 from sarcoplasmic reticulum in cardiac and skeletal muscles.Use-Asthma, COPD, chronic bronchitis 