Sidled snuggly against the small intestine just after it joins the stomach, is an under-appreciated, yet essential organ within the body: the pancreas. Looking like a flattened, lumpy, pale-colored, elongated brain, this organ is essential for blood sugar regulation and digestion. When it is upset (the pancreas can be a grumpy organ) or non-functional, numerous systems go haywire.
This one organ performs a number of jobs. The pancreas regulates blood sugar levels, and it secretes a host of hormones, regulating appetite, stomach function, stomach acid levels, and enzymes into the small intestine, which break down sugars, fats and starches. Ninety-eight percent of the pancreas secretes these enzymes, while about two percent of it makes the hormones.
Producing about eight ounces of what is colloquially called digestive juices in a person per day, the pancreas is an enzyme factory. Owing to their size, smaller amounts are produced in dogs and cats. These enzymes travel through ducts and empty into the upper part of the small intestine through two openings called the major and minor duodenal papilla in dogs. Most cats only have one papilla.
Within the pancreas are beta cells, located within a cluster of cells called Islets of Langerhans. These cells produce insulin, which is used by the body to regulate blood sugar levels and transport the sugar into individual cells. When beta cells are non-functional, diabetes mellitus results.
Insulin isn’t the only hormone produced in the pancreas. Alpha cells, comprising about 20% of the cells within the pancreas, make glucagon, which tells the liver to release stored sugars in times of need. When exercising, the body can use up all of the circulating sugars, necessitating the need for energy from other sources. Glucagon stimulates the liver to convert glycogen, a stored form of sugar, into usable energy and sugars. Gastrin, a hormone mainly made in the stomach, but also in the pancreas, stimulates the stomach to make gastric acids. Amylin, secreted by beta cells helps with appetite control and stomach emptying.
The majority of the pancreas is responsible for the production of pancreatic enzymes. Lipase works with bile from the liver to break down fats. It is essential for assisting in the absorption of fat-soluble vitamins (A, D, E, K). Protease breaks down proteins in the diet. This enzyme also protects the body from certain bacteria and yeast that are found within the intestines. Amylase, the last major enzyme, cleaves starches into sugars, which are used for energy.
When the pancreas goes awry, havoc can ensue. The most common pancreatic disorder is Type 1 diabetes, where the beta cells in the Islets are destroyed (or otherwise minimally functional). This can occur secondary to an auto-immune disease or from severe pancreatic damage. Without sufficient beta cells, blood sugar levels can be dangerously elevated and the body is incapable of sufficiently taking the sugar into the cells. Treatment usually involves regular dosing of insulin.
Loss of the enzyme-producing portion of the pancreas can also occur post severe infection or chronic pancreatic inflammation. Without sufficient digestive enzymes, weight loss occurs along with chronic diarrhea and malabsorption of nutrients. Stool may be discolored and even appear to have a fatty, glistening appearance. Known as exocrine pancreatic insufficiency, this disorder is over-represented in German Shepherd dogs, but can be found in any breed. The condition can be remedied via the administration of pancreatic enzymes on food or via capsule.
Inflammation of the pancreas, called pancreatitis, may either acutely or chronically scar the pancreas. Invading bacteria from the small intestine can cause pancreatic damage, as well as trauma and even gallstones in the bile. Acute pancreatitis can be life-threatening and usually requires hospitalization and supportive care. The chronic form may result in slow, but sustained damage to the organ.
For a non-descript, relatively ugly-looking organ, the pancreas performs a variety of essential functions.
Dan Teich, DVM, is medical director at District Veterinary Hospitals at Eastern Market and Navy Yard