Age-dependent alterations in mitochondrial enzymes in cortex, striatum and hippocampus of rat brain -- potential role of L-Carnitine.
Mitochondria link the energy -- releasing activities of electron transport and proton pumping with the energy conserving process of oxidative phosphorylation to form ATP. A declined mitochondrial performance has been generally observed during aging. In the present investigation, the activities of tricarboxylic acid cycle enzymes such as isocitrate, alpha-ketoglutarate, succinate and malate dehydrogenases and electron transport complexes I-IV were measured in mitochondria isolated from brain regions like cortex, striatum and hippocampus of young and aged rats before and after L-Carnitine supplementation. All the three brain regions of aged rats showed decreased activities of isocitrate, alpha-ketoglutarate and succinate dehydrogenases, complexes I and IV when compared to control young rats. Striatum seems to be the most susceptible region when compared to hippocampus and cortex. L-Carnitine supplementation to aged rats reversed the activities of these enzymes to near normal whereas treatment to young rats did not show any significant alterations. These results confirm that L-Carnitine can alleviate the age-associated decline in the metabolic efficiency of mitochondria in all three brain regions under investigation.
Haripriya
Dayalan
D
Department of Medical Biochemistry, Dr AL Mudaliar Post Graduate Institute of Basic Medical Sciences, University of Madras, Taramani Campus, Chennai 600 113, India.
Devi
Muthuswamy Anusuya
MA
Kokilavani
Vedagiri
V
Sangeetha
Purushotham
P
Panneerselvam
Chinnakannu
C
D000375:Aging / Q000378:metabolism*; D000818:Animals; D002331:Carnitine / Q000008:administration & dosage*; D002540:Cerebral Cortex / Q000201:enzymology*; D003342:Corpus Striatum / Q000201:enzymology*; D006624:Hippocampus / Q000201:enzymology*; D008297:Male; D008928:Mitochondria / Q000201:enzymology; D051381:Rats; D017208:Rats, Wistar
D002331:Carnitine