Sandyk R
NeuroCommunication Research Laboratories, Danbury, CT 06811, USA.
Int J Neurosci. 1996 Mar;85(1-2):93-9. doi: 10.3109/00207459608986354.
5-HT2 receptors regulate sleep including yawning behavior. Ritanserin, a selective 5-HT2A receptor antagonist, increases the duration of slow wave in rats and humans. This effect is more pronounced during the light period when melatonin plasma levels are low; melatonin inhibits the sleep effects of ritanserin. These findings indicate that melatonin co-determines the effects of ritanserin on sleep. In a cohort of multiple sclerosis (MS) patients ketanserin, a selective 5-HT2A receptor antagonist, induces recurrent yawning particularly when administered in daytime. The frequency of yawning induced by the drug was modified by AC pulsed picotesla flux electromagnetic fields (EMFs) which affect melatonin secretion. Two MS patients are presented in whom the frequency of ketanserin-induced yawning was altered in opposite directions by these EMFs. The first patient, a 50 year old woman with a remitting-relapsing course, developed recurrent yawning and sleepiness after administration of ketanserin (10 mg, PO). Yawning was decreased dramatically during application of EMFs but was unaffected by a placebo EMFs treatment. The second patient, a 35 year old man with a chronic progressive course, manifested a single and brief yawn after administration of an equal dose of ketanserin. Yawning was increased dramatically during application of EMFs while remaining unchanged during a placebo EMFs treatment. These observations demonstrate a bidirectional effect of picotesla flux EMFs on ketanserin-induced yawning which may be related to differences in daytime melatonin plasma levels among MS patients. If validated by estimations of melatonin plasma levels in a larger cohort of patients the information derived from the effects of picotesla EMFs on ketanserin-induced yawning could be used to: (a) assess pineal melatonin functions in patients with MS; (b) indicate differences in pineal functions between male and female MS patients; and (c) indicate a relationship between plasma melatonin levels and the fatigue of MS.
5-羟色胺2（5-HT2）受体调节睡眠，包括打哈欠行为。利坦色林是一种选择性5-HT2A受体拮抗剂，可增加大鼠和人类慢波睡眠时间。在褪黑素血浆水平较低的光照期，这种作用更为明显；褪黑素会抑制利坦色林的睡眠效应。这些发现表明，褪黑素共同决定了利坦色林对睡眠的影响。在一组多发性硬化症（MS）患者中，选择性5-HT2A受体拮抗剂酮色林会诱发反复打哈欠，尤其是在白天给药时。影响褪黑素分泌的交流脉冲皮特斯拉通量电磁场（EMF）会改变药物诱发打哈欠的频率。本文介绍了两名MS患者，这些电磁场使酮色林诱发打哈欠的频率发生了相反方向的改变。第一名患者是一名50岁的女性，病程为缓解-复发型，服用酮色林（10毫克，口服）后出现反复打哈欠和嗜睡。在应用电磁场期间，打哈欠次数显著减少，但安慰剂电磁场治疗对其没有影响。第二名患者是一名35岁的男性，病程为慢性进行型，服用等量酮色林后出现单次短暂打哈欠。在应用电磁场期间，打哈欠次数显著增加，而安慰剂电磁场治疗期间则保持不变。这些观察结果表明，皮特斯拉通量电磁场对酮色林诱发的打哈欠具有双向作用，这可能与MS患者白天褪黑素血浆水平的差异有关。如果通过对更多患者队列的褪黑素血浆水平进行评估得到验证，那么从皮特斯拉电磁场对酮色林诱发打哈欠的影响中获得的信息可用于：（a）评估MS患者的松果体褪黑素功能；（b）指出男性和女性MS患者松果体功能的差异；（c）表明血浆褪黑素水平与MS患者疲劳之间的关系。
