Downs Jodi L, Mattison Julie A, Ingram Donald K, Urbanski Henryk F
Division of Neuroscience, Oregon National Primate Research Center, Beaverton, OR 97006, USA.
Neurobiol Aging. 2008 Sep;29(9):1412-22. doi: 10.1016/j.neurobiolaging.2007.03.011. Epub 2007 Apr 8.
Dietary caloric restriction (CR) slows aging, extends lifespan, and reduces the occurrence of age-related diseases in short-lived species. However, it is unclear whether CR can exert similar beneficial effects in long-lived species, like primates. Our objective was to determine if CR could attenuate purported age-related changes in the 24-h release of adrenal steroids. To this end, we examined 24-h plasma profiles of cortisol, and dehydroepiandrosterone sulfate (DHEAS) in young and old, male and female rhesus macaques (Macaca mulatta) subjected to either ad libitum (AL)-feeding or CR (70% of AL) for 2-4 years. Hormone profiles from young monkeys showed pronounced 24-h rhythms. Cortisol concentrations were higher in old males but not females, whereas DHEAS rhythms were dampened with age in both sexes. The cortisol rhythms of old CR males resembled those of young control males. However, CR failed to prevent age-related declines in DHEAS and further dampened DHEAS rhythms in both sexes. Apart from the partial attenuation of the age-related cortisol elevation in the old males, 24-h adrenal steroid rhythms did not benefit from late-onset CR.
饮食热量限制（CR）可延缓衰老、延长寿命并减少短命物种中与年龄相关疾病的发生。然而，目前尚不清楚CR是否能在灵长类等长寿物种中发挥类似的有益作用。我们的目的是确定CR是否能减弱肾上腺类固醇24小时释放中所谓的与年龄相关的变化。为此，我们检测了接受自由采食（AL）或CR（AL的70%）2至4年的年轻和年老、雄性和雌性恒河猴（猕猴）的皮质醇和硫酸脱氢表雄酮（DHEAS）的24小时血浆水平。年轻猴子的激素水平呈现出明显的24小时节律。老年雄性的皮质醇浓度较高，而雌性则不然，而两性的DHEAS节律均随年龄增长而减弱。老年CR雄性的皮质醇节律与年轻对照雄性相似。然而，CR未能阻止DHEAS与年龄相关的下降，并且进一步减弱了两性的DHEAS节律。除了部分减弱老年雄性中与年龄相关的皮质醇升高外，24小时肾上腺类固醇节律并未从晚期开始的CR中获益。
