Catecholamines are hormones made chiefly by the adrenal glands, located above the kidneys. The main catecholamines are adrenaline (epinephrine), noradrenaline (norepinephrine), and dopamine.
Catecholamines increase heart rate, blood pressure, breathing rate, muscle strength, and mental alertness. They also reduce the amount of blood going to the skin and increase blood flow to the major organs, such as the brain, heart, and kidneys. Catecholamines are often released into the bloodstream in response to stress or fright and prepare the body for "fight-or-flight."
Inotropic medicines, such as dobutamine, mimic the action of catecholamines in the heart and can help strengthen the heartbeat.