Further Studies on Choline Deficiency and Muscular Dystrophy in Rabbits

Abstract

Choline deficiency in rabbits fed the peanut meal-casein basal diet was characterized by poor growth, early death, fatty and cirrhotic liver, badly damaged heart muscle and valves, high creatine and low creatinine excretion, and hyaline degeneration of striated muscle. Betaine hydrochloride added to the diet at the 0.3% level markedly improved growth, prevented deaths and the muscle damage, but did not prevent heart and liver damage at the level fed. Choline chloride at 0.12% gave complete protection. This diet contained an adequate level of α-tocopherol. Choline deficiency in rabbits fed the 20% casein basal diet was characterized by edema, hydrothorax, ascites, and early death. About one-half of the cases had approximately normal liver fat and only mild to moderate liver cirrhosis. Incoordination, paralysis, and head retractions were common, but they did not necessarily correlate with the severity of the histopathology of striated muscle. Choline-deficient rabbits had a prolonged blood clotting time. Choline-deficient rabbits required 1.16 mg dl,α-tocopheryl acetate/day/kg, as compared with choline supplemented controls which required 0.44 mg/day/kg. As previously shown, however, 10-fold the normal level of vitamin E will not protect against the muscular dystrophy and creatinuria produced by choline deficiency. Methionine deficiency in rabbits resulted in moderate weight-loss, death, creatinuria, paralysis and severe hyaline degeneration of striated muscle. Supplements of methionine or of homocystine were equally effective in preventing these deficiency symptoms.