Does nutrients modulate food-intake behavior? Measurement of neurotransmitters using in vivo brain microdialysis in diabetic rat.

在本工作中，主要进行以下研究：（Exp.1）糖尿病动物是否存在与人类糖尿病患者相似的进食异常行为；（表2）饮食行为的异常是否会导致糖尿病大脑中神经递质的释放改变，从而可能导致对应激源的脆弱；在众多的食物中，咖啡及其主要成分是否对减压有效。（表1）以WBN/Kob大鼠和KK/Ta小鼠为自发性糖尿病动物，以正常wistar大鼠和C57/BL小鼠为对照。糖尿病动物自发性运动活动减弱。在正常和糖尿病动物中，急性应激（100min限制）引起食物和水摄入量的减少，并且食物和水摄入量的昼夜节律受到干扰，特别是在糖尿病小鼠中。（表2）本实验采用活体脑微透析法测定WBN…More /Kob大鼠、STZ诱导的糖尿病大鼠和正常Wistar大鼠海马血清素（5-HT）和多巴胺（DA）水平。正常Wistar大鼠5-HT水平最大，stz大鼠次之，WBN/Kob大鼠次之。WBN/Kob大鼠体内5-HT水平约为正常大鼠的一半，DA水平约为正常大鼠的十分之一。多种离子通道阻滞剂的实验提示糖尿病突触离子通道功能障碍。（表3）急性约束应激导致海马5-HT水平显著升高。在正常大鼠中，咖啡、咖啡因、绿原酸和生理盐水预处理的“第二次抑制时5-HT峰值/第一次抑制时5-HT峰值”（应激松弛指数）分别约为37%、34%、130%和85%。这表明，喝咖啡有助于放松自制压力，进一步说，咖啡的这种效果可能是由于咖啡中含有的咖啡因。另一方面，在WBN大鼠中，咖啡、咖啡因和生理盐水预处理的应激松弛指数分别约为45%、51%、68%和85%，表明糖尿病动物对应激源的脆弱性。少

In the present work, the following studies were undertaken : (Exp.1) Whether the abnormal behavior of food intake in diabetic animals just like human diabetic patients exists or not ; (Exp.2) Whether the abnormality of food-intake behavior will be responsible for the altered release of neurotransmitters in the diabetic brain or not, presumably permitting the frailty to stressors ; (Exp.3) Whether among many foods coffee and its main components are effective in stress-ralaxation or not. (Exp.1) WBN/Kob rat and KK/Ta mouse as spontaneously diabetic animal, and normal Wistar-rats and C57/BL mouse as thc control were used. In diabetic animals the spontaneous locomotor activity decreased. In both normal and diabetic animals, acute stress (100 min-restraint) elicited the decrease in food- and water-intake, and the circadian rhythm of food- and water-intake was disturbed especially in diabetic mice. (Exp.2) In this experiment the hippocampal levels of serotonin (5-HT) and dopamine (DA) of WBN … More /Kob rat, streptozotocin (STZ)-induced diabetic rat and normal Wistar rat were measured using in vivo brain microdialysis method. The 5-HT level in normal Wistar rat was the largest value, followed by that in STZ-rat and WBN/Kob rat in that order. The 5-HT level in WBN/Kob rat was about a half of that of the normal rat, and the DA level in WBN/Kob rat was about one-tenth of that of the normal rat. The experiment using several ion channel blockers suggested the dysfunction of ion channels in diabetic synapse. (Exp.3) Acute restraint stress led to prominent increase in the hippocampal levels of 5-HT.In normal rat, "peak 5-HT value during 2nd restraint/peak 5-HT value during 1st restraint" (stress-ralaxing index) in pretreatment of coffee, caffeine, chlorogenic acid and saline was about 37%, 34%, 130% and 85%, respectively. This suggests that the administration of coffee contributes to relaxation of restraint stress and further this effect of coffee could be due to the caffeine which is contained in the coffee. On the other hand, in WBN rat, the stress-ralaxing index in pretreatment of coffee, caffeine, and saline was about 45%, 51%, 68% and 85%, respectively, suggesting the frailty to stressors in diabetic animals. Less