D'Anci K E, Kanarek R B, Marks-Kaufman R
Tufts University Department of Psychology, Medford, MA 02155, USA.
Pharmacol Biochem Behav. 1997 Mar;56(3):341-5. doi: 10.1016/s0091-3057(96)00227-4.
The effects of saccharin, sucrose, or Polycose intake on morphine-induced analgesia (MIA) were examined in 40 adult male Long-Evans rats. Rats were tested for MIA on a tail-flick apparatus following acute (5-h) and chronic (3-wk) intake of a 0.15% saccharin solution, a 32% sucrose solution, a 33.68% Polycose solution, or water. During the chronic phase, all rats were given a choice between the test solution and water. Morphine sulfate was administered according to a cumulative dosing procedure beginning with 2.5 mg/kg morphine. The same dose was administered every 30 min. Tail-flick latencies were measured immediately prior to injections and 30 min following each injection. After acute intake of flavored solutions or water, there were no differences in MIA as a function of diet. However, after drinking the flavored solutions or water for three weeks rats drinking Polycose or sucrose showed significantly enhanced MIA relative to rats drinking saccharin. Rats drinking Polycose also showed enhanced MIA relative to rats drinking water. Comparison between the acute and chronic phases of the study demonstrated that tolerance to morphine's analgesic effects did not develop in rats drinking Polycose or sucrose, but did develop in rats drinking saccharin or water. The results support the hypothesis that, in addition to palatability, the nutritive value of flavored solutions influences MIA.
在40只成年雄性Long-Evans大鼠中研究了糖精、蔗糖或聚葡萄糖摄入对吗啡诱导镇痛（MIA）的影响。在急性（5小时）和慢性（3周）摄入0.15%糖精溶液、32%蔗糖溶液、33.68%聚葡萄糖溶液或水后，在甩尾装置上对大鼠进行MIA测试。在慢性阶段，所有大鼠都可以在测试溶液和水之间进行选择。根据累积给药程序给予硫酸吗啡，起始剂量为2.5mg/kg吗啡。每30分钟给予相同剂量。在每次注射前和注射后30分钟测量甩尾潜伏期。急性摄入调味溶液或水后，MIA作为饮食的函数没有差异。然而，在饮用调味溶液或水三周后，饮用聚葡萄糖或蔗糖的大鼠相对于饮用糖精的大鼠表现出显著增强的MIA。饮用聚葡萄糖的大鼠相对于饮用清水的大鼠也表现出增强的MIA。该研究急性和慢性阶段的比较表明，饮用聚葡萄糖或蔗糖的大鼠对吗啡镇痛作用没有产生耐受性，但饮用糖精或水的大鼠产生了耐受性。结果支持了这样一种假设，即除了适口性外，调味溶液的营养价值也会影响MIA。
