NCIt definition : A substituted phenylaminoethanol and a long-acting beta-2 adrenergic agonist with
sympathomimetic activity. Clenbuterol selectively binds to and activates beta-2 adrenergic
receptors in bronchiolar smooth muscle, thereby causing stimulation of adenyl cyclase,
the enzyme that catalyzes the conversion of adenosine triphosphate (ATP) to cyclic-3',5'-adenosine
monophosphate (cAMP). Increased intracellular cAMP levels cause relaxation of smooth
muscle. In addition, clenbuterol also stimulates central nervous system (CNS), and
causes an increase in blood pressure and heart rate due to both beta-2 and beta-1
adrenergic activities. This agent may also exert an anabolic or anti-catabolic effect
due to as of yet unidentified mechanisms.;