Changes in body temperature and sleep-wakefulness after intrapreoptic injection of methoxamine in rats.
Changes in body temperature and sleep-wakefulness after intrapreoptic injection of methoxamine in rats.
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DOI：
10.1155/np.2003.267
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发表时间：
2003
影响因子：
3.1
通讯作者：
Kumar VM
中科院分区：
文献类型：
--
作者：
Vetrivelan R;Mallick HN;Kumar VM
多项证据表明，内侧视前区的去甲肾上腺素能传入神经通过作用于 α1 肾上腺素能受体来产生睡眠和体温过低。另一方面，在一些用直肠探针监测体温的研究中，视前注射α1肾上腺素激动剂甲氧胺会导致体温和睡眠-觉醒发生矛盾的变化。这种矛盾要求使用遥测记录等更好的技术重新检查甲氧胺引起的体温变化。在本研究中，我们将0.5、1和2μmol甲氧明微注射到成年雄性Wistar大鼠的内侧视前区后，同时监测体温和睡眠觉醒。甲氧明注射会导致体温降低，但注射后 3 小时内睡眠-觉醒状态没有重大变化，除了注射 120 分钟后出现短暂（15 分钟）睡眠外。当给予较高剂量的甲氧明时，会出现短暂的清醒期，与体温最大下降（注射后 30 分钟）同时发生。这项研究的结果表明，1 肾上腺素能受体参与视前介导的降低体温的温度调节措施。甲氧明引起的体温过低可能掩盖了该药物的催眠作用。
Several pieces of evidence suggest that the noradrenergic afferents in the medial preoptic area produce sleep and hypothermia by acting on α1 adrenergic receptors. On the other hand, in a few studies monitoring body temperature with a rectal probe, preoptic injection of the α1 adrenergic agonist methoxamine produced contradictory changes in body temperature and sleep-wakefulness. Such contradictions call for the re-examination of methoxamine induced body temperature changes using a better technique like telemetric recording. In the present study, we monitored body temperature and sleep-wakefulness simultaneously after the micro-injection of 0.5, 1, and 2 μmol methoxamine, into the medial preoptic area of adult male Wistar rats. Methoxamine injection produced hypothermia but no major change in sleep-wakefulness during the 3 hours after drug injection, except for a short period (15 min) of sleep after 120 min of injection. A short period of wakefulness, coinciding with the maximum fall in body temperature (30 min after injection) occurred when methoxamine was administered at higher doses. The results of this study indicate that 1 adrenergic receptors participate in preoptically mediated thermoregulatory measures that reduce body temperature. Hypothermia induced by methoxamine might have masked the hypnogenic action of this drug.