Tempel D L, Leibowitz S F
Rockefeller University, New York, NY 10021.
Brain Res Bull. 1990 Dec;25(6):821-5. doi: 10.1016/0361-9230(90)90177-2.
The feeding responses elicited by injection of norepinephrine (NE), neuropeptide Y (NPY) and galanin (GAL) into the paraventricular nucleus (PVN) were studied at two different times of the dark (active) cycle in male Sprague-Dawley rats maintained ad lib on pure nutrient diets. The feeding response elicited by NE in the PVN, characterized by a potent and selective stimulatory effect on ingestion of the carbohydrate diet, was significantly stronger during the early dark period (+11.7 kcal over vehicle baseline) relative to the late dark period (+7.6 kcal). A similar pattern of effects was observed with NPY in the PVN, which also selectively potentiated carbohydrate ingestion. The effects of GAL were different from those observed with NE and NPY. Whereas the total amount of food consumed after PVN GAL injection was similar in the early and late dark periods, the macronutrient selection patterns exhibited at these two times were different. During the early dark period, PVN GAL had a small stimulatory effect on carbohydrate, in addition to a strong enhancement of fat intake; in the late dark period, in contrast, GAL stimulated intake only of the fat diet. These findings may reflect differential functions of these hypothalamic neurotransmitters in controlling nutrient ingestion at different periods of the circadian cycle.
在自由采食纯营养日粮的雄性斯普拉格-道利大鼠的黑暗（活跃）周期的两个不同时间，研究了向室旁核（PVN）注射去甲肾上腺素（NE）、神经肽Y（NPY）和甘丙肽（GAL）所引发的摄食反应。PVN中NE引发的摄食反应，其特征是对碳水化合物日粮的摄取具有强大且选择性的刺激作用，相对于黑暗后期（高于载体基线+7.6千卡），在黑暗前期（高于载体基线+11.7千卡）明显更强。在PVN中观察到NPY有类似的效应模式，它也选择性地增强了碳水化合物的摄取。GAL的效应与NE和NPY所观察到的不同。虽然在黑暗前期和后期，PVN注射GAL后消耗的食物总量相似，但在这两个时间呈现的常量营养素选择模式不同。在黑暗前期，PVN GAL除了强烈增强脂肪摄入外，对碳水化合物有轻微的刺激作用；相反，在黑暗后期，GAL仅刺激脂肪日粮的摄入。这些发现可能反映了这些下丘脑神经递质在昼夜周期不同阶段控制营养摄取方面的不同功能。
