Mancilla-Diaz Juan Manuel, Escartin-Perez Rodrigo Erick, Lopez-Alonso Veronica Elsa, Floran-Garduño Benjamin, Romano-Camacho Jose Bernardo
Laboratory of Alimentary Neurobiology, Universidad Nacional Autonoma de Mexico, FES Iztacala, Mexico.
Med Sci Monit. 2005 Mar;11(3):BR74-9.
Feeding behavior is deeply affected by serotonergic neurotransmission. This regulatory activity is mediated mainly by specific 5-HT1/2 receptors, and the paraventricular nucleus (PVN) plays a key role in this phenomena. In order to reveal the involvement of 5-HT1A and 5-HT1B receptors in the paraventricular nucleus of the hypothalamus (PVN) on serotonin-induced hypophagia, we examined the effects of intra-PVN injections of serotonin in WAY 100635 or SB 216641-pretreated rats on the structure of feeding behavior.
MATERIAL/METHODS: Male Wistar rats were kept at 21+/-1 degrees C with a 12 h light /dark cycle on a self-selection feeding paradigm, provided with freely available and separate sources of protein, carbohydrate, fat and water. Blockade of 5-HT1A or 5-HT1B receptors in the paraventricular nucleus was effected by WAY 100635 (2 microg) or SB-216641 (2 microg) pretreatment; ten minutes later, 5-HT (2 microg) was applied into the same nucleus, then food intake and meal patterns were measured in a 30-minute period. The behavioral test was conducted at the beginning of the dark phase.
The suppressive effect of 5-HT on carbohydrate intake was blocked by both WAY 100635 and SB 216641 at the beginning of the active (dark) feeding period.
The hypophagic effect induced by 5-HT requires activation of 5-HT1A and 5-HT1B receptors, and the specific contribution of these subtype receptors is different, since the 5-HT1A subtype showed higher behavioral selectivity.
摄食行为受血清素能神经传递的深刻影响。这种调节活动主要由特定的5 - HT1/2受体介导，而室旁核（PVN）在这一现象中起关键作用。为了揭示下丘脑室旁核（PVN）中的5 - HT1A和5 - HT1B受体在血清素诱导的摄食减少中的作用，我们研究了在经WAY 100635或SB 216641预处理的大鼠中，向PVN内注射血清素对摄食行为结构的影响。
材料/方法：雄性Wistar大鼠饲养在21±1摄氏度，光照/黑暗周期为12小时的自选摄食模式下，提供可自由获取的蛋白质、碳水化合物、脂肪和水源。通过WAY 100635（2微克）或SB - 216641（2微克）预处理来阻断室旁核中的5 - HT1A或5 - HT1B受体；十分钟后，将5 - HT（2微克）注入同一核团，然后在30分钟内测量食物摄入量和进食模式。行为测试在黑暗期开始时进行。
在活跃（黑暗）摄食期开始时，WAY 100635和SB 216641均阻断了5 - HT对碳水化合物摄入的抑制作用。
5 - HT诱导的摄食减少效应需要激活5 - HT1A和5 - HT1B受体，并且这些亚型受体的具体作用不同，因为5 - HT1A亚型表现出更高的行为选择性。
