Abstract
It was shown 1 that the completely depancreatized dog can survive for well over 4 years when maintained with insulin and a diet containing meat, sucrose, bone ash and vitamin supplements, B (in the form of a rice bran concentrate), and A and D (as cod liver oil). No other accessory substances were found essential. Despite their survival, however, such dogs are not normal in all respects. The appearance of cataracts was first observed in this laboratory as early as one year after pancreatectomy. 2 A striking change also takes place in the lipid metabolism. When the animals are maintained on the dietary constituents listed above, there occurs a fall in all blood lipid constituents and a rise in the lipid content of the liver. 3 , 4 It was then shown that the addition of raw pancreas to the diet not only decreased the lipid content of the liver to the normal level but also effected a rise in the blood lipids to values far in excess of the preoperative or normal level. 5 The maintenance of a high blood lipid level was observed only so long as raw pancreas was being ingested, the exclusion of the glandular tissue from the diet resulting in a precipitous fall in the lipid level, which finally reached a value below the normal. The ability of raw pancreas, when administered per os, to cause these fluctuations in the blood lipids, as well as its effect on the lipid metabolism of the liver, suggested that this glandular tissue contained a substance—entirely apart from insulin—capable of influencing lipid metabolism. Since choline has been claimed to effect a cure of the fatty livers of the depancreatized dog, 6 it became necessary, in the process of identifying the pancreatic lipid factor, to study the effects of choline on the blood lipids of the completely depancreatized dog maintained with insulin.
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