Carnitine palmitoyl transferase-I activity in the aging mouse heart.
We investigated the influence of age on carnitine palmitoyl transferase-I (CPT-I, EC 2.3.1.21) activity in the mouse heart. There was an age-associated decrease in CPT-I activity from 2 to 26 months (P = 0.006). We studied the effect of oxygen-derived radicals on CPT-I activity. Mitochondria from 2-month-old mouse hearts exposed to different concentrations of hydrogen peroxide (H2O2) showed a dose-related decrease in CPT-I activity (P < 0.002). To determine the possible reversibility of the age change in CPT-I activity, we studied the effect of oral administration of propionyl-L-carnitine (PLC). Oral pretreatment of middle-aged (18-month-old) mice with PLC resulted in a 37% increase of basal CPT-I activity (P < 0.05) compared to age-matched untreated animals, and restored it to a level similar to that of 2-month-old mice. Pretreatment of senescent (26-month-old) mice with PLC, however, showed no significant change in basal CPT-I activity. It is possible that the age-related decrease in CPT-I activity may result from an in vivo accumulation of oxygen-derived radical damage. It appears that the age change in CPT-I activity in 18- but not in the 26-month-old mice is reversible with PLC.
Odiet
J A
JA
Division on Aging, Harvard Medical School, Beth Israel Hospital, Boston, MA 02215, USA.
Boerrigter
M E
ME
Wei
J Y
JY
D000375:Aging / Q000378:metabolism*; D000818:Animals; D002316:Cardiotonic Agents / Q000494:pharmacology*; D002331:Carnitine / Q000031:analogs & derivatives* / Q000494:pharmacology; D002334:Carnitine O-Palmitoyltransferase / Q000378:metabolism*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008929:Mitochondria, Heart / Q000187:drug effects; D015428:Myocardial Reperfusion Injury / Q000188:drug therapy; D009206:Myocardium / Q000201:enzymology*
D002316:Cardiotonic Agents; C003223:propionylcarnitine; D002334:Carnitine O-Palmitoyltransferase; D002331:Carnitine