Enterochromaffin cell

Enterochromaffin (EC) cells (Kulchitsky cells) are a type of enteroendocrine cell occurring in the epithelia lining the lumen of the gastrointestinal tract.

Function
They produce and contain about 90% of the body's store of serotonin (5-HT).

In the gastrointestinal tract, 5-HT is important in response to chemical, mechanical or pathological stimuli in the lumen. It activates both secretory and peristaltic reflexes, and activates vagal afferents (via 5-HT3 receptors) that signal to the brain (important in the generation of nausea).

Ondansetron is an antagonist of the 5-HT3 receptor and is an effective anti-emetic.

Etymology
They are called "entero" meaning related to the gut and "chromaffin" because of a chromium salt reaction that they share with chromaffin cells of the adrenal medulla (adrenal glands).

"Enterochromaffin-like cells"
Another population of chromaffin cells is found only in the stomach wall, called enterochromaffin-like cells (ECL). They look like EC cells but do not contain 5-HT.

ECL cells respond to acetylcholine released by the vagus nerve and they in turn release histamine, which will stimulate the parietal cells to produce gastric acid.

Pathophysiology
Kulchitsky cells, or neuroendocrine cells, have been implicated in the origin of small cell lung cancer.