Function of the Pancreas

As mentioned above, an ideal insulin delivery system would supply insulin as a function of the concentration of glucose in the semm. This is what the pancreas does, among other things. Any candidate system for delivery of insulin should be evaluated in terms of the capabilities of the pancreas. The following performance parameters enter into this evaluation  

Non-invasivemss. The integrity of the body barrier functions should not have to be breached to administer the iasuhn. 

Delivery rate control. The pancreas secretes iasuhn at a low basal rate that is specific to the individual. A replacement system should also be able to deliver insulin at a basal rate that is specific to the user. This basal rate is on the order of 12 units per hour. 

Bolus administration. The pancreas is able to rapidly secrete insulin to respond to food intake. A replacement system should also be able to deliver a variable amount of insulin in a short amount of time to handle a meal. This bolus can range up to 20 units. 

Dose precision. The pancreas delivers almost exactly what the body needs. A replacement system should, at a minimum, reproducibly deliver a given insulin dose. 

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It is common practice to discontinue oral feedings during an attack of acute pancreatitis. In theory, discontinuation of oral intake will decrease the secretory functions of the pancreas and minimize further complications from the disease. Some patients can be fed with minimal oral intake. Tube feeding delivered via a nasojejunal tube will feed the patient beyond the ampulla of Vater, minimizing stimulation of the pancreas.15,16 If oral intake is discontinued for a protracted period, total parenteral nutrition must be used to maintain adequate nutrition.17,18... 

Chronic pancreatitis is an inflammatory process that occurs over a long period of time. The inflammation damages the enzyme-producing cells in the pancreas and can also disrupt or destroy the endocrine function of the pancreas by causing diffuse... 

As patients lose exocrine function of the pancreas, they have decreased ability to absorb lipids and protein ingested with normal dietary intake. Weight loss from nutritional malabsorption is a common symptom of chronic pancreatitis not often seen in acute pancreatitis. Fatty- or protein-containing stools are also common carbohydrate absorption is usually unaffected. Even though patients with chronic pancreatitis have decreased ability to absorb lipid from the gastrointestinal tract, there does not appear to be an increased incidence of fat-soluble vitamin deficiency in these patients.34... 

Glucose intolerance may occur because of chronic destruction of the endocrine function of the pancreas.35... 

The effects of parenteral nutrition on endocrine and exocrine functions of the pancreas have been investigated in experimental rats (906). The conclusion was that after parenteral nutrition treatment the insulin secretory... 

Diarrhea may cause acidosis as a result of loss of Na, Kfi and HCOJ. One of the primary exocrine functions of the pancreas is production of HCOs to neutralize gastric contents on entry into the duodenum. If the water, K", and HCO7 in the intestine are not reabsorbed, a hypokalemic, normal anion gap metabolic acidosis will develop. The resulting hyperchloremia is due to the replacement of lost bicarbonate with Cr to maintain electrical balance. 

The predominant exocrine functions of the pancreas are the production and secretion of pancreatic juice, which is rich in enzymes and bicarbonate. Normal pancreatic juice is colorless and odorless it has a pH of 8.0 to 8.3 and a specific gravity of 1.007 to 1.042. The total 24-hour secretion volume may be as high as 3000 mL. ... 

An oral drug, a derivative of sulfonylurea, capable of lowering blood glucose (sugar) when a functioning pancreas is still present. Since it acts by stimulating the release of insulin, it may be used in the treatment of diabetes when there is still some residual function of the pancreas. 

In the case of pancreas transplantation, only one case has been reported corresponding to a patient that received kidney and pancreas transplants and after treated by ECP for acute rejection [171]. Unfortunately, in this study, the function of the pancreas allograft before or after photopheresis was not reported. 

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