Gruenewald D A, Marck B T, Matsumoto A M
Geriatric Research, Education, and Clinical Center, Department of Veterans Affairs Medical Center, Seattle, Washington 98108, USA.
Endocrinology. 1996 Oct;137(10):4460-7. doi: 10.1210/endo.137.10.8828508.
Aging in man is associated with alterations in food intake (FI) and body weight (BW). To establish a model of age-related alterations in FI and BW regulation, FI and BW were determined in young (3-month-old), middle-aged (12-month-old), and old (24-month-old) male Brown Norway rats during ad libitum feeding and after 72 h of fasting. FI was reduced with aging both during ad libitum feeding and after fasting. With fasting, young rats lost more BW than older rats, but regained BW more rapidly during refeeding. To determine whether age-related impairments in FI and BW regulation are mediated by neuropeptide Y (NPY), a potent stimulator of FI, we compared arcuate nucleus prepro-NPY (ppNPY) messenger RNA (mRNA) by in situ hybridization in fasted and ad libitum-fed (fed) young, middle-aged, and old rats. ppNPY mRNA declined with aging in both fed and fasted rats. Although ppNPY mRNA increased with fasting in all age groups, this response was attenuated with aging. In conclusion, impaired FI and BW recovery after fasting is associated with reduced NPY responsiveness to fasting in aging rats. Impaired activation of the hypothalamic NPY pathway may, therefore, contribute to age-related alterations in FI and BW regulation.
人类衰老与食物摄入量（FI）和体重（BW）的改变有关。为了建立FI和BW调节的年龄相关改变模型，在随意进食期间以及禁食72小时后，测定了年轻（3个月大）、中年（12个月大）和老年（24个月大）雄性挪威棕色大鼠的FI和BW。在随意进食期间和禁食后，FI均随着衰老而降低。禁食时，年轻大鼠比老年大鼠体重减轻更多，但在重新进食期间体重恢复更快。为了确定FI和BW调节的年龄相关损伤是否由神经肽Y（NPY，一种强大的FI刺激物）介导，我们通过原位杂交比较了禁食和随意进食（进食）的年轻、中年和老年大鼠弓状核前神经肽Y（ppNPY）信使核糖核酸（mRNA）。在进食和禁食的大鼠中，ppNPY mRNA均随着衰老而下降。尽管在所有年龄组中ppNPY mRNA都随着禁食而增加，但这种反应随着衰老而减弱。总之，禁食后FI和BW恢复受损与衰老大鼠中NPY对禁食的反应性降低有关。因此，下丘脑NPY途径的激活受损可能导致FI和BW调节的年龄相关改变。
