Effect of choline upon experimental canine arteriosclerosis.

Studies have been made of the effect of excess dietary choline upon the arteriosclerosis produced in dogs by a regimen of cholesterol and thiouracil feeding. The choline-fed animals did not differ significantly from the control animals with respect to serum lipid levels, degree of lipid infiltration of their livers or severity of arteriosclerotic involvement. C HOLINE is currently being promoted for the treatment of human arterio-sclerosis. Its use is based upon certain theoretic considerations, upon limited clinical experience, and upon observations of its effect in preventing and curing experimental arterio-sclerosis in animals. It has been postulated that since choline has powerful lipotropic activity in preventing the development of certain types of fatty deposition in the liver and kidneys, and in accelerating the removal of fat from these deposits after they are formed, it should also be effective in preventing and curing arteriosclerotic deposits. However, choline is most effective in curing conditions caused by the ingestion of diets deficient in choline. It has little effect on fatty livers caused by feeding cholesterol, or on fatty livers resulting from mobilization of lipid from body deposits.' It has also been suggested that choline may have a specific "catalytic" role in the metabolism of lipids,2 although such a function has never been demonstrated. A third theoretic basis for the use of choline is derived from the concept that the stability of cholesterol in serum may be important in the pathogenesis of arterio-sclerosis. Most of the cholesterol in normal human serum is held in solution by being part of lipoprotein molecules which contain protein, cholesterol, cholesterol esters, and phospho-lipids.3 Since choline is a constituent of some phospholipids its administration might contribute to phospholipid formation and thus to stabilization of serum cholesterol. Regardless of possible theoretic bases for the use of choline in the treatment of arterio-sclerosis, the final decision as to its value must be made on the basis of its actual effect upon the disease. The impossibility of quanti-tation of human arteriosclerosis makes evaluation of clinical data difficult. Evidence of its value in experimental arteriosclerosis in animals is inconclusive and conflicting. Reports that choline is effective in delaying or preventing the development of atheromatous lesions in cholesterol-fed rabbits and chickens4-6 have been contradicted by other workers using the same species and similar technics.7'9 For this reason the influence of choline upon the development of experimental arteriosclerosis in a third species, the dog, has been …