A Review of Normal Function and Role of Gastrin in Zollinger-Ellison

When Gastrin Goes Awry: A Review of Normal Function and Role of Gastrin in Zollinger-Ellison Syndrome Leigha LaTourette1, Janel Cross2, Barbara Brabetz2 Department of Plant and Animal Science1, Department of Natural Sciences and Mathematics2

Introduction Gastrin: Normal Mode of Action Gastrin’s Role in Zollinger-Ellison Syndrome MEN 1 & ZES Gastrin is a digestive hormone that acts on the MEN1 is an inheritable disease that causes over neuroendocrine and parietal cells of the secretion of hormones via tumors on the gastrointestinal tract to ultimately secrete gastric endocrine glands throughout the body.4 Around a acid. Gastrin secretion begins even before food 30% of these tumors are found to be malignant. is consumed, as the mere anticipation of a meal ZES is commonly associated with the MEN1 due can lead to a series of events ending in the to the presence of tumors found in the stomach creation of the gastric acid needed to breakdown and small intestine.4 These gastrointestinal foods. Not only does Gastrin support the tumors caused by MEN 1 give the person a digestion of foods, but it also stimulates growth, higher likelihood of contracting ZES, as the secretion, blood flow, and acts as a defense probability of having pancreatic or duodenal mechanism against bacteria in the tumors is increased.4 gastrointestinal system. When the production of Gastrin becomes overt, major consequences like that of Zollinger Ellison Syndrome (ZES). ZES is an extremely rare disease occurring in people between the ages of 30-60.4 ZES is related to the uncontrolled secretion of gastrin due to the presence of certain pancreatic or duodenal tumors. The tumor stimulates the acid-secreting cells of the stomach to maximal activity, with consequent gastrointestinal mucosal ulceration.

Roles of Gastrin in the Human Body Figure 8: “Little” Gastrin-171 . Stimulates the secretion of gastric acid by the Little Gastrin-17 is one of the many active parietal cells of the stomach forms of gastrin produced by G-cells. G-cells . Assists in the absorption of some vitamins cleave progastrin, a large inactive form of Digestive system background no labels11 11 . Kills harmful bacteria found on food Digestive system background no labels gastrin in response to vagal stimulation. . Causes secretion of other digestive enzymes Figure 1: Gastrin’s Normal Mode of Action in Figure 2: Gastrin’s Mode of Action in a . Triggers blood flow, gastric movement and the Human Body person with ZES Acknowledgments mucosal growth in the gastrointestinal system The authors would like to acknowledge the SUNY When Gastrin Goes Awry: Zollinger-Ellison Syndrome Cobleskill Print Shop for their time and efforts in ZES is a disease that can cause neuroendocrine tumors in the pancreas, known as printing the many posters for the Student Research gastrinomas.2 These tumors secrete large quantities of gastrin, and therefore increasing Showcase, as well as the Student Research Showcase committee for their commitment and involvement in 2 the production and release of gastric acid in the stomach. The increased secretion of student success. gastric acid results in perforation and irritation of the gastric and duodenal wall. ZES is difficult to diagnose as the use of proton pump inhibiting drugs like Nexium can mask the diagnosis.3 Figure 9: Gastrin Action in the stomach9 References 3 2 1. Sigma-Aldrich.Gastrin I, Human. 2018.Darmstadt,Germany. Symptoms Diagnosis Treatment 2. Cingam SR, Karanchi H. (2017). Gastrinoma. Stat Pearls Publishing. Retrieved from: https://www.ncbi.nlm.nih.gov/pubmed/2872 • Frequent Abdominal Pain • Fasting Serum Gastrin Levels • High dose of proton pump 3. Ito, T., Igarashi, H., & Jensen, R. T. (2013). Zollinger-Ellison syndrome:Recent advances Current Studies and controversies. Current Opinion in Gastroenterology, 29(6), 650–661. inhibitors 4. National Organization for Rare Disorders (NORD). (2015). Zollinger Ellison Syndrome. Current Studies in Gastrin are centralized Retrieved from: rarediseases.org. • Nausea • Serum Calcium Levels • Surgery to remove the 5. Burks, T.F. (2010) Gastrointestinal Toxicology. Little Gastrin 1. around ZES, a disease causing gastrointestinal 6. Betty Crocker. (2015). Ultimate Chocolate Chip Cookies. [Photograph]. affected area 7. National Institute of Diabetes and Digestive Kidney Disease. (2012).Zollinger-Ellison mucosal ulceration. A clinical study in Japan is Syndrome (ZES). [Photograph]. • Blood in Vomit and Stool • Gastric Acid Secretory Tests 8. Sapboriboon, Sarah. (2007). Distal Duodenal Ulcer. [Photograph]. currently exploring the clinical presentation of 9. APSU Biology. (2014). Gastric Phase. [Photograph]. 10. Chapman. (2005). Parietal Cell. [Photograph]. 3 ZES and the accuracy of ZES diagnosis. • Heartburn • Provocative Tests 11. Anatomy Medical. (2018). Digestive System Diagram Without Labels. [Clipart].

Figure 10: Background Image. Parietal Cells in the Stomach9