PROPIONYLCARNITINE PHYSIOLOGICAL VARIATIONS IN VIVO

1. 1. Propionylcarnitine has been identified as a relatively important carnitine derivative in liver and kidney in male rats. 2. 2. In the liver of fed rats the ratio of propionylcarnitine/free carnitine + propionylcarnitine was 22% and in the kidney 4%. Fasting reduced this ratio to 1% in both liver and kidney. In the other organs the ratio was 1% or less in both normally fed and fasted rats. 3. 3. Feeding corn oil to rats previously given a diet rich in carbohydrate reduced the level of propionylcarnitine in the liver to fasting values within 4 h. 4. 4. The changes in the propionylcarnitine level in the liver are exactly opposite to those in the long-chain acylcarnitines. 5. 5. The results are discussed in relation to the regulatory mechanisms in mitochondrial metabolism. © 1968.