Neuroendocrine tumors NETs also known as islet cell tumors a

Neuroendocrine tumors (NETs), also known as \"islet cell tumors\" are relatively rare cancers for which the majority (85%) function to produce hormones. NETs include Insulinomas, Gastrinomas, and Glucagonomas. In fact Zollinger-Ellison Syndrome (ZES) is the cause of a form of peptic ulcer disease (PUD) resulting from neoplastic duodenal or pancreatic G cells. Describe how a gastrinoma causing ZES might cause PUD and discuss the extent to which H2- receptor antagonists or proton pump inhibitors would be effective in reducing the symptoms associated with ZES.

Solution

The gastric acid (HCl) is ssecreted by parietal cells of stomach in response to gastrin hormone. It occurs when the aromatic peptides are present in the stomach. The tumors of G cells cause Zollinger-Ellison syndrome which is characterized by ulcers of post bulbar and duodenum along wth severe diarrhea. Since the gastrin hormone stimulates the secretion of gastric acid, the higher gastrin levels (>1000pg/mL) leads to gastric acid hypersecretion even in absence of food in stomach and thereby causes breaks in the linings of stomach and duodenum. The condition is called as peptic ulcers.
The proton pump inhibitors reduce the gastric acid secretion by inhibiting the H⁺/K⁺-ATPase of gastric parietal cells. Since these inhibitors irreversibly bind to the proton pump to inhibit the final step in the production of gastric acid, these are very effective in reducing the peptic ulcers by reducing the gastric acidity.