Wang S W J
Department of Behavioral Neuroscience, University of British Columbia, Vancouver, Canada.
Eat Weight Disord. 2002 Mar;7(1):23-31. doi: 10.1007/BF03354426.
The present study investigated the effects of brief (20 min), acute (2 hr) and chronic restraint stress (2 hr/day for five days) at the time of dark onset on macronutrient selection in female Wistar rats. The role of 5-HT1A receptors in nutrient intake was also examined in a dose-response study (100-700 microg/kg body weight) of 8-hydroxy-2-(di-n-propylamino) tetralin (DPAT) in an acute restraint model. A total of 200 rats aged 6-12 months were tested. In all cases, the restraint stress took the form of confinement within tight-fitting cylinder tubes. In the brief and acute paradigms, the intake of pure carbohydrate (CHO), protein (PRO), and fat was measured for 40 min after a single exposure to stress; in the chronic model, nutrient intake was assessed for 40 min only after the final restraint stress session on day 5. In the DPAT paradigm, intraperitoneal injections of the 5-HT1A agonist were given prior to acute restraint and a 40 min session of nutrient self-selection. Statistical analysis using the t-test for independent samples revealed that neither PRO nor total intake was significantly altered by restraint in the brief, acute or chronic restraint experiments, whereas CHO consumption was suppressed by acute (p=0.02) and chronic restraint (p=0.021), and fat intake was suppressed by brief (p=0.010), acute (p=0.002) and chronic restraint (p=0.001). In the DPAT paradigm, acute restraint stress suppressed CHO (p=0.0001), fat (p=0.000001) and total intake (p=0.003). These effects were not reversed by DPAT, and the administration of 300 pg/kg actually further reduced fat intake. In conclusion, fat intake is more sensitive to the suppressive effects of restraint stress than CHO intake, whereas protein intake is unaffected. Furthermore, 5-HT1A receptors do not seem to play a role in the effects of acute restraint on CHO and fat intake.
本研究调查了在黑暗开始时施加短暂（20分钟）、急性（2小时）和慢性束缚应激（每天2小时，持续五天）对雌性Wistar大鼠常量营养素选择的影响。在急性束缚模型中，还通过8-羟基-2-（二正丙基氨基）四氢萘（DPAT）的剂量反应研究（100 - 700微克/千克体重）考察了5-HT1A受体在营养摄入中的作用。总共测试了200只6 - 12个月大的大鼠。在所有情况下，束缚应激均采取将大鼠限制在紧身圆柱管内的形式。在短暂和急性范式中，单次应激暴露后40分钟测量纯碳水化合物（CHO）、蛋白质（PRO）和脂肪的摄入量；在慢性模型中，仅在第5天最后一次束缚应激 session 后40分钟评估营养摄入量。在DPAT范式中，在急性束缚和40分钟营养自我选择之前腹腔注射5-HT1A激动剂。使用独立样本t检验的统计分析表明，在短暂、急性或慢性束缚实验中，束缚均未显著改变PRO或总摄入量，而急性（p = 0.02）和慢性束缚（p = 0.021）抑制了CHO消耗，短暂（p = 0.010）、急性（p = 0.002）和慢性束缚（p = 0.001）抑制了脂肪摄入。在DPAT范式中，急性束缚应激抑制了CHO（p = 0.0001）、脂肪（p = 0.000001）和总摄入量（p = 0.003）。这些作用未被DPAT逆转，300微克/千克的给药实际上进一步降低了脂肪摄入。总之，脂肪摄入比CHO摄入对束缚应激的抑制作用更敏感，而蛋白质摄入不受影响。此外，5-HT1A受体似乎在急性束缚对CHO和脂肪摄入的影响中不起作用。
