Relation of the Pancreas to the Regulation of the Blood Lipids

Abstract

Determinations of total serum lipids were made in a large number of normal dogs, depancreatized dogs, and dogs with total pancreatic fistulae or occluded pancreatic ducts under controlled conditions and when fed raw pancreas or pancreas extracts. It is concluded that the pancreas exerts a proximal effect in the regulation of the blood lipids by means of an internal secretion, lipocaic, which potentiates the lipotropic effect of choline and similar substances in the diet. In the absence of the pancreas or when its endocrine function is impaired, the presence of pancreatic juice in the intestines causes hyperlipemia and a high insulin requirement. Withdrawal of pancreatic juice from the intestines of dogs with impaired endocrine function of the pancreas causes hypolipemia, decreased insulin requirement intolerance, and fatty infiltration of the liver. Total serum lipids of normal dogs vary between 500 and 900 mg%. Fasting for periods of 14 - 36 days produced no constant change in level of the serum lipids. A progressive decrease in serum lipids occurred in insulin treated depancreatized dogs and a similar, but more rapid, decrease occurred in animals with occlusion of the pancreatic ducts and degeneration of the pancreatic parenchyma. Sub-total pancreatectomy, leaving a remnant of pancreas weighing from 1-2 g attached to a pancreatic duct, produced diabetes characterized by a very high insulin requirement to prevent glycosuria and a marked hyperlipemia. These animals could be preserved in excellent nutritive state by insulin alone and without supplementary pancreas feeding. Deviation of the pancreatic juice from this small remnant of pancreas to the exterior lowered the insulin requirement to that of completely depancreatized dogs, abolished the hyperlipemia and produced the other changes which occur after complete pancreatectomy. Deviation of pancreatic juice by means of an external fistula, however, did not produce hypolipemia and fatty livers if sufficient normal pancreas was present so that glycosuria was absent. Oral administration of fresh beef pancreas to depancreatized dogs or dogs with ligated pancreatic ducts, either with or without partial pancreatectomy, produced a marked elevation in the serum lipids usually to hyperlipemic levels. In contrast, oral administration of raw pancreas to normal dogs failed to raise the lipid level higher than that seen in animals in good nutrition. The hyperlipemia associated with thyroid deficiency may be superimposed upon the hyperlipemia produced by sub-total pancreatectomy producing lipid levels which may reach 4 times the normal value.