Inbred mouse strains differ in their postoral appetite stimulating response (appetition) to fructose as demonstrated in intragastric (IG) sugar conditioning and oral sugar vs. nonnutritive conditioning experiments. For example, FVB and SWR strains show experience-induced preferences for 8% fructose over a 0.1% sucralose + 0.1% saccharin (S + S) solution, whereas C57BL/6 (B6) and BALB/c strains do not. All strains, however, learn to prefer 8% glucose to S + S after experience, which is attributed to the potent appetition actions of this sugar. The present study extended this analysis to DBA/2 (DBA) and 129P3 (129) inbred mice. In Experiment 1A, ad libitum fed DBA and 129 mice preferred S + S to fructose before and after separate experience with the two sweeteners, indicating an indifference to the postoral nutrient effects of the sugar. When food restricted (Experiment 1B), 129 mice continued to prefer S + S to fructose while DBA mice showed equal preference for the sweeteners after experience, indicating some sensitivity to fructose appetition. In Experiment 1C, both strains acquired significant preferences for glucose over S + S after experience, confirming their sensitivity to postoral glucose appetition. Experiment 2 revealed that C57BL/6 × 129P3 (B6:129) hybrid mice responded like inbred B6 mice and 129 mice in acquiring a preference for glucose but not fructose over S + S. This is of interest because sweet "taste-blind" P2 × 2 / P2 × 3 double-knockout (DKO) mice on a B6:129 genetic background prefer fructose to water in 24 h tests, which is indicative of fructose appetition. Whether differences in the genetic makeup of DKO and B6:129 hybrid mice or other factors explain the fructose appetition of the DKO mice remains to be determined.

正如在胃内 (IG) 糖调节和口服糖与非营养调节实验中所证明的那样，近交小鼠品系对果糖的后食欲刺激反应（食欲）不同。例如，FVB 和 SWR 菌株在 0.1% 三氯蔗糖 + 0.1% 糖精 ( S  +  S ) 溶液中表现出对 8% 果糖的偏好，而 C57BL/6 (B6) 和 BALB/c 菌株则没有。然而，所有菌株都在经历后学会更喜欢 8% 的葡萄糖而不是S  +  S，这归因于这种糖的强效食欲作用。本研究将此分析扩展到 DBA/2 (DBA) 和 129P3 (129) 近交小鼠。在实验 1A 中，随意喂食 DBA 和 129 只小鼠首选S  +  S分别使用两种甜味剂之前和之后的果糖，表明对糖的后营养作用无差异。当食物受到限制时（实验 1B），129 只小鼠继续偏爱S  +  S而不是果糖，而 DBA 小鼠在经历后对甜味剂表现出同样的偏爱，表明对果糖食欲有些敏感。在实验 1C 中，两种菌株在经历后都获得了对葡萄糖的显着偏好，而不是S  +  S，证实了它们对口服葡萄糖食欲的敏感性。实验 2 表明，C57BL/6 × 129P3 (B6:129) 杂交小鼠的反应与近交 B6 小鼠和 129 小鼠相似，在获得对葡萄糖而非果糖的偏好方面优于S  +  S. 这很有趣，因为 B6:129 遗传背景下的甜“味盲”P2 × 2 / P2 × 3 双基因敲除 (DKO) 小鼠在 24 小时测试中更喜欢果糖而不是水，这表明对果糖有食欲。DKO 和 B6:129 杂交小鼠的基因组成差异或其他因素是否解释了 DKO 小鼠的果糖食欲仍有待确定。