Absorption and excretion of L-carnitine during single or multiple dosings in humans.
Changes of short-chain (free) and long-chain (acyl) carnitine activity (CA) in plasma, whole blood, red blood cells (rbc) and urine were induced (a) by ingestion of L-carnitine as a single dose of 500 mg, or 2500 mg, or (b) by ingestion of a daily dose of 2500 mg for 10 days. A single 500-mg dose induced insignificant increases of CA in blood constituents. However elevated free CA was noted in urine. Single or daily high doses--e.g. 2500 mg of carnitine--significantly increased free and acyl-CA in plasma, whole blood and urine, but these increases were low. Variations in dosage or frequency of carnitine intake led to no changes in rbc CA; presumably CA in plasma diffused only slowly into rbc. The apparent low absorption of carnitine suggests that oral therapy may not effect rapid repletion of body stores of CA.
Baker
H
H
Department of Preventive Medicine, New Jersey Medical School, Newark.
Frank
O
O
DeAngelis
B
B
Baker
E R
ER
D000328:Adult; D002331:Carnitine / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics* / Q000652:urine; D004334:Drug Administration Schedule; D004912:Erythrocytes / Q000378:metabolism; D006801:Humans; D007408:Intestinal Absorption / Q000502:physiology; D008875:Middle Aged
D002331:Carnitine