<prompt> Which enzyme is inhibited by aminophylline?Monoamine oxidaseAlcohol dehydrogenasePhosphodiesteraseCytochrome  <response>: Aminophylline Methylxanthine inhibits phosphodiesterase which degrades cyclic neucleotides intracellularly. Ref: Essentials of Pharmacology By K D Tripathi, 5th Edtion, Page 202. 