Acetyl-L-carnitine supplementation differently influences nutrient partitioning, serum leptin concentration and skeletal muscle mitochondrial respiration in young and old rats.
Variations in energy balance, body composition, and nutrient partitioning induced by acetyl-L-carnitine (ALCAR) supplementation were studied in young (2 mo) and old (24 mo) Wistar rats. Changes in skeletal muscle metabolism as well as in serum free triiodothyronine and leptin levels were also evaluated. Rats were administered 0 (control) or 15 g/L ALCAR in their drinking water for 1 mo. ALCAR treatment significantly decreased body lipid percentage in young rats and significantly increased body protein percentage in old rats. The percentage of metabolizable energy (ME) intake stored as lipid was lower in ALCAR-treated young rats, whereas the percentage of ME intake stored as protein was greater in ALCAR-treated old rats compared with their age-matched controls. In addition, ALCAR supplementation significantly decreased serum leptin levels in old rats. Elevated skeletal muscle respiration was found in old rats treated with ALCAR, due to an increase in mitochondrial protein mass. In conclusion, ALCAR supplementation decreases efficiency of lipid deposition in young rats and increases efficiency of protein deposition in old rats. In addition, ALCAR supplementation partly reduces the leptin resistance that occurs in old rats, and improves ATP production in skeletal muscle mitochondria through an increase in mitochondrial protein content.
Iossa
Susanna
S
Department of General and Environmental Physiology, University of Naples Federico II, Italy I-80134.
Mollica
Maria Pina
MP
Lionetti
Lillà
L
Crescenzo
Raffaella
R
Botta
Monica
M
Barletta
Antonio
A
Liverini
Giovanna
G
D000108:Acetylcarnitine / Q000494:pharmacology*; D000375:Aging / Q000378:metabolism*; D000704:Analysis of Variance; D000818:Animals; D001481:Basal Metabolism; D001823:Body Composition; D004734:Energy Metabolism / Q000187:drug effects*; D020738:Leptin / Q000097:blood*; D008297:Male; D008928:Mitochondria / Q000378:metabolism; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000201:enzymology; D018697:Nootropic Agents / Q000494:pharmacology*; D010101:Oxygen Consumption / Q000187:drug effects*; D051381:Rats; D017208:Rats, Wistar; D013385:Succinate Dehydrogenase / Q000378:metabolism
D020738:Leptin; D018697:Nootropic Agents; D000108:Acetylcarnitine; D013385:Succinate Dehydrogenase