A chemical produced and secreted by the adrenal glands. It can act as a stimulant, increasing blood pressure, heart rate, and other functions. It is a neurotransmitter, or substance which transmits nerve signals from neuron to neuron, and is also a hormone that helps break glycogen (a polysaccharide) down into glucose (a simple sugar). It has the chemical formula C9H13NO3.
From the BioTech Dictionary at http://biotech.icmb.utexas.edu/. For further information see the BioTech homenode.