Long-term calorie restriction has minimal impact on brain metabolite and fatty acid profiles in aged rats on a Western-style diet

• Published in: Neurochemistry international Vol. 63; no. 5; pp. 450 - 457
• Main Authors: Roy, Maggie, Hennebelle, Marie, St-Pierre, Valérie, Courchesne-Loyer, Alexandre, Fortier, Mélanie, Bouzier-Sore, Anne-Karine, Gallis, Jean-Louis, Beauvieux, Marie-Christine, Cunnane, Stephen C.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.11.2013
• Subjects: Aged rat; Animals; Brain - metabolism; Brain fatty acid; Caloric Restriction; Calorie restriction; Cortex; Diet; Fatty Acids - metabolism; HRMAS 1H NMR; Magnetic Resonance Spectroscopy; Male; Rats; Rats, Sprague-Dawley; MIns; MUFA; Gln; Tau; Cho; HRMAS 1H NMR; SFA; Glu; Aged rat; Calorie restriction; β-HB; Asp; PUFA; GLUT; Cortex; HRMAS; AL; CR; Lac; NAA; NMR; Brain fatty acid; Ala; GABA; GPC; MCT; polyunsaturated fatty acids; β-hydroxybutyrate; monocarboxylic acid transporter; glutamine; N-acetylaspartate; myo-inositol; HRMAS H NMR; choline; ad libitum; total creatine; glucose transporter; alanine; saturated fatty acids; aspartate; glutamate; high resolution magic angle spinning; taurine; monounsaturated fatty acids; nuclear magnetic resonance; glycerophosphocholine; γ-aminobutyric acid; lactate
• ISSN: 0197-0186; 1872-9754
• DOI: 10.1016/j.neuint.2013.08.006

•On a high-sucrose, low omega-3 diet, aged rats had higher brain GLUT1 than young rats.•Aged rats had higher brain cortex metabolites compared to young rats.•Long-term calorie restriction (CR) did not change brain metabolites in aged rats.•Long-term CR did not change brain cortex fatty acids in aged rats.•Long-term CR reduced brain microvessel MCT 1 expression in aged rats. 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 2month old ad libitum-fed (2AL group), (ii) a 19month old ad libitum-fed (19AL group), and (iii) a 19month old group subjected to 40% CR from the age of 7.5 to 19months (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-1H 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.