Ackroff K, Sclafani A, Axen K V
Department of Psychology, Brooklyn College and the Graduate School of New York City University, 11210, USA.
Appetite. 1997 Feb;28(1):73-83. doi: 10.1006/appe.1996.0058.
Prior studies indicate that glucose has a more potent postingestive reinforcing effect than fructose. The role of insulin in this effect was examined by comparing sugar-conditioned flavor preferences in normal and streptozotocin-diabetic rats. In Experiment 1, diabetic rats, like normal rats, preferred a cue flavor that had been mixed into 8% glucose solution over a flavor mixed with 8% fructose. Both taste and postingestive properties of glucose may have contributed to this preference. Experiment 2 evaluated postingestive reinforcement by pairing cue flavors with intragastric infusions of glucose and fructose. Both diabetics and normals acquired a preference for the flavor paired with intragastric 16% glucose infusions over the flavor paired with 16% fructose infusions although the preference was somewhat smaller in the diabetic rats. Taken together, the results indicate that a normal insulin secretory response to glucose is not required for glucose-conditioned flavor preference. The diabetic rats' reduced flavor preference in Experiment 2 suggests that insulin may play some role in glucose conditioning although this may be secondary to alterations in gastrointestinal motility characteristic of diabetic animals.
先前的研究表明，葡萄糖在摄入后比果糖具有更强的强化作用。通过比较正常大鼠和链脲佐菌素诱导的糖尿病大鼠对糖 conditioned 味道的偏好，研究了胰岛素在这种作用中的角色。在实验 1 中，糖尿病大鼠和正常大鼠一样，比起与 8%果糖混合的味道，更喜欢与 8%葡萄糖溶液混合的提示味道。葡萄糖的味觉和摄入后特性可能都导致了这种偏好。实验 2 通过将提示味道与胃内注入葡萄糖和果糖配对来评估摄入后强化作用。糖尿病大鼠和正常大鼠都对与胃内注入 16%葡萄糖配对的味道产生了偏好超过与 16%果糖注入配对的味道，尽管糖尿病大鼠的偏好稍小。综合来看，结果表明对葡萄糖的正常胰岛素分泌反应对于葡萄糖 conditioned 味道偏好并非必需。实验 2 中糖尿病大鼠味道偏好降低表明胰岛素可能在葡萄糖 conditioning 中起一定作用，尽管这可能继发于糖尿病动物胃肠道运动特性的改变。
