Enterochromaffin cell

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

Function
They 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.

They are stimulated by gastrin, a molecule that is produced at the antrum of the stomach by G cells.

Origin
They are derived from neural crest.

The enterochromaffin cells are derived from the same stem cells as the rest of the epithelium, and are not derived from the migratory neural crest source that provides the enteric nervous system.

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 gastrin released by G-cells and they release histamine, which will stimulate the parietal cells to produce gastric acid.

Pathophysiology
Neuroendocrine progenitor cells in the bronchial epithelium, the progenitors to Kulchitsky cells, have been implicated in the origin of small cell lung cancer.