APUD cells constitute a group of apparently unrelated endocrine cells that share the common function of secreting a low molecular weight polypeptide hormone. APUDoma in dogs refer to tumors that originate from these cells lining the gastrointestinal tract. APUD stands for amine precursor uptake and decarboxylation (APUD). The tumors of these endocrine cells are known as apudomas.
The apude cells are generally found in gastrointestinal tract and CNS. Intestinal apudoma refers to tumors originating in the endocrine cells of GI tract. These cells secrete peptide hormone which is vital in regulating metabolism, growth, development, and tissue function. The tumor(s) cause Hypergastrinemia — an excess of gastrin (hormon that stimulates secretion of gastric juices) which in turn causes gastric and duodenal hyperacidity, resulting in gastric ulceration, esophageal dysfunction from chronic refux, and damage to the intestinal lining. Gastric hyperacidity is also caused by high concentration of pancreatic polypeptide.
Common symptoms associated with apudoma include