Pich E M, Messori B, Zoli M, Ferraguti F, Marrama P, Biagini G, Fuxe K, Agnati L F
Institute of Human Physiology, University of Modena, Italy.
Brain Res. 1992 Mar 20;575(2):265-71. doi: 10.1016/0006-8993(92)90089-r.
Neuropeptide Y (NPY), a peptide of the pancreatic polypeptide family, exerts a potent stimulatory action on eating when injected into the paraventricular hypothalamic nucleus (PVN) in rats. Several NPY-containing systems are altered with advancing age, and aged rodents develop anorexia and a modified daily cycle pattern of feeding. These findings suggest that a relationship may exist between the aging-related anorexia and the reduced function of NPY-containing systems projecting to the PVN. In the present study eating and drinking behavior in satiated or fasted young (3 months) and aged (24 months) rats have been investigated over 22 h after NPY injection into the PVN. The levels of NPY immunoreactivity (IR) in PVN were also evaluated by means of semiquantitative immunocytochemistry. NPY injections into PVN increased food and water consumption in both young and aged satiated rats 30, 90 and 240 min after injection. However, the feeding and drinking responses elicited by 0.05, 0.10 and 1.0 nmol of NPY were significantly attenuated in the aged rats when compared to young rats. In aged rats, 24 h of food and water deprivation produced significant increase of food consumption measured at 30, 90 min and 22 h, which was equivalent to that induced by 1.0 nmol NPY injection. Administration of 1.0 nmol NPY in PVN did not further increase the 24 h deprivation effect on feeding in both groups of rats, but enhanced drinking in deprived young rats. This effect was not present in aged rats. In addition, aged rats showed a stronger response to 24 h deprivation than to 1.0 nmol NPY administration.(ABSTRACT TRUNCATED AT 250 WORDS)
神经肽Y（NPY）是一种胰多肽家族的肽，当注射到大鼠下丘脑室旁核（PVN）时，对进食有强大的刺激作用。随着年龄的增长，几个含NPY的系统会发生改变，老年啮齿动物会出现厌食和进食的日常周期模式改变。这些发现表明，与衰老相关的厌食症和投射到PVN的含NPY系统功能降低之间可能存在关联。在本研究中，对饱足或禁食的年轻（3个月）和老年（24个月）大鼠在向PVN注射NPY后22小时内的进食和饮水行为进行了研究。还通过半定量免疫细胞化学方法评估了PVN中NPY免疫反应性（IR）的水平。向PVN注射NPY后30、90和240分钟，年轻和老年饱足大鼠的食物和水消耗量均增加。然而，与年轻大鼠相比，0.05、0.10和1.0 nmol NPY引起的老年大鼠进食和饮水反应明显减弱。在老年大鼠中，24小时的食物和水剥夺在30、90分钟和22小时测量时导致食物消耗量显著增加，这与1.0 nmol NPY注射引起的增加量相当。在两组大鼠中，向PVN注射1.0 nmol NPY并未进一步增加24小时剥夺对进食的影响，但增强了剥夺的年轻大鼠的饮水。老年大鼠没有这种效果。此外，老年大鼠对24小时剥夺的反应比对1.0 nmol NPY给药的反应更强。（摘要截断于250字）
