Authors
Hagen TM. Ingersoll RT. Wehr CM. Lykkesfeldt J. Vinarsky V. Bartholomew
JC. Song MH. Ames BN.
Institution
Department of Molecular and Cell Biology, University of California, Berkeley,
CA 94720, USA.
Title
Acetyl-L-carnitine fed to
old rats partially restores mitochondrial function and
ambulatory activity.
Source
Proceedings of the National Academy of Sciences of the United States of
America. 95(16):9562-6, 1998 Aug 4.
Abstract
Mitochondrial function and ambulatory activity were monitored after feeding
old rats acetyl-L-carnitine (ALCAR). Young
(3-5 mo) and old (22-28 mo) rats were given a 1.5% (wt/vol)
solution of ALCAR in their drinking water for 1 mo, were sacrificed, and
their liver parenchymal cells were isolated. ALCAR supplementation
significantly reverses the age-associated decline of mitochondrial membrane
potential, as assessed by rhodamine 123 staining. Cardiolipin, which declines
significantly with age, is also restored. ALCAR increases cellular oxygen
consumption, which declines with age, to the level of young rats. However,
the oxidant production per oxygen consumed, as measured by
2',7'-dichlorofluorescin fluorescence levels, is approximately 30% higher
than in untreated old rats. Cellular glutathione and
ascorbate levels were nearly 30% and 50% lower, respectively, in cells from
ALCAR-supplemented old rats than in untreated
old rats, further indicating that ALCAR supplementation
might increase oxidative stress. Ambulatory activity in young and
old rats was quantified as a general measure of metabolic
activity. Ambulatory activity, defined as mean total distance traveled, in
old rats is almost 3-fold lower than in
young animals. ALCAR supplementation increases ambulatory activity
significantly in both young and old rats, with the increase
being larger in old rats. Thus, ALCAR supplementation to
old rats markedly reverses the age-associated decline in
many indices of mitochondrial function and general metabolic activity, but
may increase oxidative stress.
Additional note by poster:
Low dose lipoic acid also helps reverse mitochondrial function, but does not increase oxidative stress, so this may be a preferable supplement for fragile elderly humans to try. Lipoic acid does have the side effect of increasing biotin requirements, so extra biotin should be given as well to prevent a deficiency.
Pyruvate is another supplement that may be helpful in the elderly.