Question

is it necessary that only catecholamine can bind to adrenergic receptors?​

Answer 1

Adrenergic receptors (adrenoceptors) are receptors that bind adrenergic agonists such as the sympathetic neurotransmitter NE and the circulating hormone epinephrine (EPI). ... Circulating catecholamines (epinephrine) released by the adrenal medulla also bind to these same alpha and beta adrenoceptors in the heart.