You are treating a 38-year-old man with complaints of near constant burning pain in his upper stomach which gets worse when he lies down at night. He informs you that his stools are black and that he frequently vomits up blood. You diagnose your patient as suffering from severe GI ulcerations and you suspect they are caused by Zollinger-Ellison syndrome. However, a gastric biopsy shows no apparent gastrinomas. Abnormal activity in the secretory function of which of the following cell types would most likely be associated with the symptoms in this patient?

Question

Quizplus · Accepted Answer

ECL cells are responsible for producing gastrin, which stimulates acid secretion by parietal cells. In Zollinger-Ellison syndrome, a gastrinoma (a tumor of ECL cells) causes excessive gastrin production, leading to severe GI ulcerations. The principal stimulants for acid secretion are histamine, gastrin, and acetylcholine (ACh) released from postganglionic enteric neurons. Histamine is thought to be the primary stimulus. Histamine is released from enterochromaffin-like (ECL) cells in response to gastrin binding to these cells in fundal glands of the upper stomach. The released histamine then binds to H 2 receptors on parietal cells inducing a signaling cascade that results in the transport of the H⁺/K⁺-ATPase (proton pump) from the cytoplasm to the apical plasma membrane of the parietal cell. Excessive release of histamine would, therefore, result in excessive secretion of gastric acid leading to ulceration of the stomach mucosal lining.

You Are Treating a 38-Year-Old Man with Complaints of near Constant