title: Caloric restriction increases ketone bodies metabolism and preserves blood flow in aging brain.
abstract: Caloric restriction (CR) has been shown to increase the life span and health span of a broad range of species. However, CR effects on in vivo brain functions are far from explored. In this study, we used multimetric neuroimaging methods to characterize the CR-induced changes of brain metabolic and vascular functions in aging rats. We found that old rats (24 months of age) with CR diet had reduced glucose uptake and lactate concentration, but increased ketone bodies level, compared with the age-matched and young (5 months of age) controls. The shifted metabolism was associated with preserved vascular function: old CR rats also had maintained cerebral blood flow relative to the age-matched controls. When investigating the metabolites in mitochondrial tricarboxylic acid cycle, we found that citrate and α-ketoglutarate were preserved in the old CR rats. We suggest that CR is neuroprotective; ketone bodies, cerebral blood flow, and α-ketoglutarate may play important roles in preserving brain physiology in aging.
authors.affiliation: Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA; Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, KY, USA. Electronic address: ailing.lin@uky.edu.
authors.forename: Ai-Ling
authors.initials: AL
authors.lastname: Lin
authors.affiliation: Research Imaging Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Institutional Mass Spectrometry Laboratory, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA; Department of Biochemistry, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Gao
authors.affiliation: Research Imaging Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA; Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.
authors.forename: Lora
authors.initials: L
authors.lastname: Watts
mesh_terms: D000375:Aging / Q000502:physiology*; D000818:Animals; D001921:Brain / Q000098:blood supply* / Q000378:metabolism*; D031204:Caloric Restriction; D002560:Cerebrovascular Circulation; D007657:Ketone Bodies / Q000378:metabolism*; D008297:Male; D011916:Rats, Inbred F344
chemical_list: D007657:Ketone Bodies
keywords: Aging; Brain metabolism; Cerebral blood flow; Ketone bodies; Mammalian target of rapamycin; Neuroimaging; α-ketoglutarate