Weldon D T, O'Hare E, Cleary J, Billington C J, Levine A S
Department of Medicine and Geriatric Research, Veterans Affairs Medical Center, Minneapolis, Minnesota 55417, USA.
Am J Physiol. 1996 Jun;270(6 Pt 2):R1183-8. doi: 10.1152/ajpregu.1996.270.6.R1183.
We studied the effect of the opioid receptor antagonist naloxone on intake of three isocaloric diets containing cornstarch, sucrose, or Polycose as the predominant carbohydrate in ad libitum-fed and food-restricted rats. A large body of evidence suggests that opioids affect palatability (reward)-rater than hunger (energy deficit)-driven food intake. We expected food intake to be driven by both energy needs and palatability in ad libitum-fed rats, whereas in food-restricted rats we expected intake to be driven by energy needs with a relatively small palatability component in the preferred sucrose and Polycose diet groups. In the ad libitum-fed rats, naloxone significantly reduced nocturnal intake of all three diets at doses of 0.3, 1.0, and 3.0 mg/kg. In contrast, naloxone failed to alter intake of the cornstarch diet in chronically food-restricted rats. However, naloxone decreased intake of the sucrose diet in food-restricted rats at doses of 0.3, 1.0, and 3.0 mg/kg and decreased intake of the Polycose diet at the 3 mg/kg dose. These data lend further support to the notion that opioids are involved in some other component of feeding than that induced by energy needs.
我们研究了阿片受体拮抗剂纳洛酮对自由采食和限食大鼠摄入三种等热量饮食的影响，这三种饮食分别以玉米淀粉、蔗糖或聚葡萄糖作为主要碳水化合物。大量证据表明，阿片类物质影响的是适口性（奖赏）驱动的食物摄入，而非饥饿（能量缺乏）驱动的食物摄入。我们预计，在自由采食的大鼠中，食物摄入由能量需求和适口性共同驱动；而在限食大鼠中，我们预计在偏好的蔗糖和聚葡萄糖饮食组中，摄入由能量需求驱动，适口性因素相对较小。在自由采食的大鼠中，纳洛酮在剂量为0.3、1.0和3.0mg/kg时显著降低了所有三种饮食的夜间摄入量。相比之下，纳洛酮未能改变长期限食大鼠的玉米淀粉饮食摄入量。然而，纳洛酮在剂量为0.3、1.0和3.0mg/kg时降低了限食大鼠的蔗糖饮食摄入量，并在3mg/kg剂量时降低了聚葡萄糖饮食摄入量。这些数据进一步支持了以下观点：阿片类物质参与了进食过程中除能量需求诱导因素之外的其他某些成分。
