Rouch C, Nicolaidis S, Orosco M
Physiopathologie de la Nutrition, CNRS ESA 7059, Université Paris 7, France.
Physiol Behav. 1999;65(4-5):653-7. doi: 10.1016/s0031-9384(98)00204-2.
In response to a chow meal in rats, we observed previously in PVN-VMH dialysates, an increase in serotonin (5-HT) that could be related to satiety or to metabolic consequences of the composition of the meal. Indeed, carbohydrates are admitted to increase 5-HT synthesis while proteins decrease it, but the time course and mechanisms of these effects were not known. For that purpose, pure carbohydrates, proteins, or fats were offered for 30 min and the changes in 5-HT from PVN-VMH dialysates were followed. Carbohydrates (85% starch + 15% sucrose) enhanced 5-HT levels as soon as the first 15 min of feeding, with a maximum 60 min later. Conversely, protein ingestion induced in the second 15 min of the meal, a decrease in 5-HT that lasted 2 h. During a fat meal (lard), 5-HT levels also decreased at the beginning of the meal and remained low during 45 min. The present data reassess the previous theories on the serotonergic effects of specific macronutrient ingestion. The effect of a fat meal on 5-HT levels had never been described so far. The increase in 5-HT in response to a carbohydrate meal is further specified. The 5-HT decrease induced by proteins, in agreement with the previous theories, is better explained now by using pure protein diets and extracellular 5-HT assay. However, all the changes observed start too early to be only metabolic in origin. Other mechanisms may occur, including the release of 5-HT in response to a meal to induce satiety.
在大鼠摄入正常饮食后，我们之前在室旁核-腹内侧核透析液中观察到，血清素（5-羟色胺，5-HT）增加，这可能与饱腹感或饮食成分的代谢后果有关。实际上，碳水化合物会增加5-HT的合成，而蛋白质则会降低其合成，但这些作用的时间进程和机制尚不清楚。为此，给予大鼠纯碳水化合物、蛋白质或脂肪30分钟，并跟踪室旁核-腹内侧核透析液中5-HT的变化。碳水化合物（85%淀粉 + 15%蔗糖）在喂食的前15分钟内就会提高5-HT水平，60分钟后达到最大值。相反，摄入蛋白质在进食的第二个15分钟内会导致5-HT下降，并持续2小时。在进食脂肪餐（猪油）期间，5-HT水平在进餐开始时也会下降，并在45分钟内保持较低水平。目前的数据重新评估了之前关于特定常量营养素摄入的血清素能效应的理论。迄今为止，从未描述过脂肪餐对5-HT水平的影响。对碳水化合物餐引起的5-HT增加有了更具体的认识。与之前的理论一致，蛋白质引起的5-HT下降，现在通过使用纯蛋白质饮食和细胞外5-HT测定法能得到更好的解释。然而，观察到的所有变化开始得太早，不可能仅仅源于代谢。可能还会发生其他机制，包括进食时释放5-HT以诱导饱腹感。
