Noradrenaline (norepinephrine) is an endogenous metabolite in mammals, also present in plant tissue. Noradrenline is a sympathomimetic hormone of both adrenal and adrenergic orthosympathetic postganglionic origin in humans. Noradrenaline directly stimulates adrenergic receptors, causing vasoconstriction of the radial smooth muscle, increase in myocardial contractility, heart rate, automaticity and atrioventricular conduction, and bronchiolar and vascular smooth muscle dilatation.