title: Long-term calorie restriction has minimal impact on brain metabolite and fatty acid profiles in aged rats on a Western-style diet.
abstract: The effect of long-term calorie restriction (CR) on metabolites, fatty acid profiles and energy substrate transporter expression in the brain was assessed in aged rats. Three groups of male Sprague-Dawley rats were studied: (i) a 2 month old ad libitum-fed (2AL group), (ii) a 19 month old ad libitum-fed (19AL group), and (iii) a 19 month old group subjected to 40% CR from the age of 7.5 to 19 months (19CR group). The diet contained high sucrose and low n-3 polyunsaturated fatty acids (PUFA) so as to imitate a Western-style diet. High resolution magic angle spinning-(1)H NMR showed an effect of aging on brain cortex metabolites compared to 2AL rats, the largest differences being for myo-inositol (+251% and +181%), lactate (+203% and +188%), β-hydroxybutyrate (+176% and +618%) and choline (+148% and +120%), in 19AL and 19 CR rats, respectively. However, brain metabolites did not differ between the 19AL and 19CR groups. Cortex fatty acid profiles showed that n-3 PUFA were 35-47% lower but monounsaturated fatty acids were 40-52% higher in 19AL and 19CR rats compared to 2AL rats. Brain microvessel glucose transporter (GLUT1) was 68% higher in 19AL rats than in 2AL rats, while the monocarboxylate transporter, MCT1, was 61% lower in 19CR rats compared to 19AL rats. We conclude that on a high-sucrose, low n-3 PUFA diet, the brain of aged AL rats had higher metabolites and microvessel GLUT1 expression compared to 2AL rats. However, long-term CR in aged rats did not markedly change brain metabolite or fatty acid profile, but did reduce brain microvessel MCT1 expression.
authors: Research Center on Aging, Université de Sherbrooke, Sherbrooke, QC, Canada; Department of Physiology and Biophysics, Université de Sherbrooke, Sherbrooke, QC, Canada. Electronic address: Maggie.Roy@USherbrooke.ca.
authors: Maggie
authors: M
authors: Roy
authors: Marie
authors: M
authors: Hennebelle
authors: Valérie
authors: V
authors: St-Pierre
authors: Alexandre
authors: A
authors: Courchesne-Loyer
authors: Mélanie
authors: M
authors: Fortier
authors: Anne-Karine
authors: AK
authors: Bouzier-Sore
authors: Jean-Louis
authors: JL
authors: Gallis
authors: Marie-Christine
authors: MC
authors: Beauvieux
authors: Stephen C
authors: SC
authors: Cunnane
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism*; D031204:Caloric Restriction; D004032:Diet; D005227:Fatty Acids / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D005227:Fatty Acids
keywords: AL; Aged rat; Ala; Asp; Brain fatty acid; CR; Calorie restriction; Cho; Cortex; Cr; GABA; GLUT; GPC; Gln; Glu; HRMAS; HRMAS (1)H NMR; Lac; MCT; MIns; MUFA; N-acetylaspartate; NAA; NMR; PUFA; SFA; Tau; ad libitum; alanine; aspartate; calorie restriction; choline; glucose transporter; glutamate; glutamine; glycerophosphocholine; high resolution magic angle spinning; lactate; monocarboxylic acid transporter; monounsaturated fatty acids; myo-inositol; nuclear magnetic resonance; polyunsaturated fatty acids; saturated fatty acids; taurine; total creatine; β-HB; β-hydroxybutyrate; γ-aminobutyric acid