Muscarine, Pituitary Adenylate Cyclase Activating Polypeptide, and Angiotensin II ‐Evoked Secretion in Adrenal Medullary Chromaffin Cells With a Major Focus on TRPC Channels

ABSTRACT Adrenal medullary chromaffin (AMC) cells secrete catecholamines in response to neuronal and humoral inputs during stress. Secreted adrenaline is crucial for organismal survival during acute and/or chronic stress, primarily through the stimulation of adrenergic β2 receptors in various cell types. While acetylcholine and/or pituitary adenylate cyclase activating polypeptide (PACAP) are involved in neuronal transmission from the sympathetic nerve fibers, depending on the stress type, angiotensin II and decreased blood pH also act as potent humoral stimulants for catecholamine secretion. Transient receptor potential canonical (TRPC) isoforms operate as distinct molecular effectors that link specific receptors to specific modes of excitation. The present review aims to elucidate how these neuronal and humoral signals independently induce excitation in AMC cells. The discussion focuses primarily on TRPC channels and the signal transduction pathways for muscarinic, PACAP, and angiotensin II receptors. image