Maternal dietary L-carnitine supplementation influences fetal carnitine status and stimulates carnitine palmitoyltransferase and pyruvate dehydrogenase complex activities in swine.
Effects of increasing maternal L-carnitine on carnitine status and energy metabolism in the fetus were evaluated by feeding pregnant swine a corn-soybean-based diet containing either 0 or 50 mg/kg added L-carnitine (n = 10/treatment) during the first 70 d of gestation. Carnitine, carnitine palmitoyltransferase (CPT), and pyruvate dehydrogenase complex (PDHC) activities were analyzed in tissues collected from fetuses on d 55 and 70. Maternal L-carnitine supplementation increased both fetal free and long-chain carnitine concentrations by 45% in liver and free carnitine by 31% in heart tissues but did not affect kidney tissue. Elevations in free and acylcarnitines increased with gestational age from 55 to 70 d in liver but not in heart and kidney. The increased carnitine concentrations resulted in a 45% increase in PDHC activity in heart and liver on d 70 of gestation but did not affect kidney and liver on d 55 of gestation. The increases in carnitine concentrations were accompanied by a 70% increase in hepatic CPT activity in 70-d-old fetuses, but activities in heart and kidney were unaffected. The Michaelis constant (K(m)) of CPT for carnitine in fetal tissues was not influenced by carnitine supplementation (P > 0.1). Notably, the concentrations of carnitine measured on d 70 were only 25-40% of the K(m) values in liver, 60-70% in heart, and 30-40% in kidney (P < 0.001). We conclude that carnitine ingestion during pregnancy increases fetal carnitine concentrations and stimulates heart PDHC and liver CPT activity without altering carnitine K(m).
Xi
Lin
L
Department of Animal Science, North Carolina State University, Raleigh, NC 27695, USA.
Brown
Kelly
K
Woodworth
Jason
J
Shim
Kwanseob
K
Johnson
Bradley
B
Odle
Jack
J
D000818:Animals; D002331:Carnitine / Q000008:administration & dosage* / Q000378:metabolism*; D002334:Carnitine O-Palmitoyltransferase / Q000378:metabolism*; D019587:Dietary Supplements; D004734:Energy Metabolism / Q000187:drug effects; D005260:Female; D005333:Fetus / Q000378:metabolism*; D007700:Kinetics; D008099:Liver / Q000201:enzymology; D008431:Maternal-Fetal Exchange; D009206:Myocardium / Q000201:enzymology; D011247:Pregnancy; D011768:Pyruvate Dehydrogenase Complex / Q000378:metabolism*; D013552:Swine
D011768:Pyruvate Dehydrogenase Complex; D002334:Carnitine O-Palmitoyltransferase; D002331:Carnitine