Research Center on Aging, Université de Sherbrooke, Sherbrooke, QC, Canada; Department of Physiology and Biophysics, Université de Sherbrooke, Sherbrooke, QC, Canada.
Neurochem Int. 2013 Nov;63(5):450-7. doi: 10.1016/j.neuint.2013.08.006. Epub 2013 Aug 22.
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.
长期热量限制（CR）对老年大鼠大脑代谢物、脂肪酸谱和能量底物转运体表达的影响进行了评估。研究了三组雄性 Sprague-Dawley 大鼠：（i）2 个月龄自由喂养（2AL 组），（ii）19 个月龄自由喂养（19AL 组），和（iii）19 个月龄从 7.5 个月到 19 个月龄时进行 40%CR 的组（19CR 组）。饮食中含有高蔗糖和低 n-3 多不饱和脂肪酸（PUFA），以模拟西式饮食。高分辨率魔角旋转-（1）H NMR 显示，与 2AL 大鼠相比，大脑皮层代谢物随年龄的变化在 19AL 大鼠中有较大差异，最大差异为肌醇（分别增加 251%和 181%）、乳酸（分别增加 203%和 188%）、β-羟丁酸（分别增加 176%和 618%）和胆碱（分别增加 148%和 120%），而 19CR 大鼠中没有差异。然而，19AL 和 19CR 组之间的大脑代谢物没有差异。皮层脂肪酸谱显示，与 2AL 大鼠相比，19AL 和 19CR 大鼠的 n-3 PUFA 降低 35-47%，而单不饱和脂肪酸增加 40-52%。19AL 大鼠大脑微血管葡萄糖转运体（GLUT1）比 2AL 大鼠高 68%，而 19CR 大鼠单羧酸转运体 MCT1 比 19AL 大鼠低 61%。我们得出结论，在高蔗糖、低 n-3 PUFA 饮食中，与 2AL 大鼠相比，老年 AL 大鼠的大脑代谢物和微血管 GLUT1 表达更高。然而，长期 CR 对老年大鼠的大脑代谢物或脂肪酸谱没有明显改变，但确实降低了大脑微血管 MCT1 的表达。
