RESTRICTING FOOD-INTAKE DOES NOT EXACERBATE THE EFFECTS OF A CHOLINE-DEFICIENT DIET ON TISSUE CARNITINE CONCENTRATIONS IN RATS

Previous reports in animals indicate that choline deficiency alters ca rnitine metabolism. Recent studies in humans suggest that choline defi ciency occurs in individuals during long term total parenteral nutriti on. Malnutrition is also a frequent complication in this population. W e therefore examined the effect of restricting the intake of a choline -deficient diet on carnitine concentrations in plasma and tissues. Adu lt male rats were randomly assigned to one of four dietary regimens: c ontrol, choline deficient, restricted control (85% of control), or res tricted choline deficient for 42-43 d. At the end of the experimental period, restricted animals weighed significantly less than their respe ctive controls (P < 0.01). Liver weight relative to body weight and fa t concentration were greater in choline-deficient animals (P < 0.01 an d 0.001, respectively). Choline-deficient rats fed free access had ele vated plasma carnitine concentration (P < 0.01). Urinary carnitine exc retion was elevated in both groups of choline-deficient rats (P < 0.01 ), while liver, heart and muscle carnitine concentrations were lower t han in controls (P < 0.05). Restricting dietary intake reduced plasma carnitine concentration in choline deficient animals (P < 0.01), but d id not alter tissue or urine carnitine concentrations in either group. Restricted, choline-deficient animals did not exhibit a worsening of the sequelae of choline deficiency. We conclude that choline deficienc y alters carnitine concentrations in plasma and tissues and that restr icting the intake of a choline-deficient diet does not alter this effe ct in tissues.