secretagogues

A secretagogue is a substance that stimulates secretion from a gland or secretory cell. Secretagogues can be endogenous regulators such as hormones and neurotransmitters or exogenous drugs used therapeutically. They act by binding to receptors or channels on secretory cells to initiate signaling cascades that raise intracellular messengers like calcium or cAMP, leading to exocytosis and fluid or hormone release.

In the pancreas, insulin secretagogues include sulfonylureas and meglitinides, which close ATP-sensitive potassium channels on beta cells, depolarize the membrane, open voltage-gated calcium channels and trigger insulin release. Glucose and incretin hormones also function as physiological secretagogues.

Gastric acid secretion is stimulated by endogenous secretagogues such as gastrin, acetylcholine, and histamine acting on parietal cells; clinically, acid secretion can be modulated with antagonists or proton pump inhibitors. Salivary secretion is stimulated by agents like pilocarpine and cevimeline, used to treat dry mouth.

Intestinal secretagogues include lubiprostone, a chloride channel activator that increases intestinal fluid secretion, and guanylate cyclase-C agonists such as linaclotide, which enhance secretion and transit.

Secretagogues may have therapeutic benefits for diabetes, xerostomia, and constipation, but adverse effects and interactions vary by agent. The term covers a broad range of substances and contexts, including physiological regulators and pharmacological agents; understanding secretagogues involves physiology of secretion, signal transduction, and clinical pharmacology.