Giardino L, Calzá L, Zanni M, Velardo A, Pantaleoni M, Marrama P
Institute of Human Physiology, University of Cagliari, Medical School, Italy.
Chronobiol Int. 1989;6(3):203-16. doi: 10.3109/07420528909056920.
The endogenous opioid peptides, the opiate receptors and several related behaviours, like opioid-mediated analgesia, show daily variations in different animal species including rats. The attempt to correlate the daily rhythm of opiate receptors in the central nervous system (CNS) to opiate related rhythmic phenomena requires an experimental approach with a high anatomical resolution, as the opioid distribution is very heterogeneous. In this paper we present the study of daily variations of 3H-naloxone binding sites in the different regions of the adult male rat brain, performed by means of quantitative autoradiography. Five rats are sacrificed at each investigated time of the day (0200, 0600, 1000, 1400, 1800 and 2200). The ligant is 3H-naloxone (4 nM), the quantification is performed by means of densitometric procedures (image analyzer Tesak VDC 501, computer Digital PDP 11, 3H-microscale). The statistical analysis is performed according to the single Cosinor method and the one-way analysis of variance followed by the multiple range test of Duncan. We analysed 33 different regions of the rat CNS, and the daily variations of opiate receptors are regionally selective. A circadian rhythm is found in the anterior cingulate cortex, hippocampal cortex, periventricular, medial, ventral, reticular and posterior nuclei of the thalamus, rhomboid, gelatinosus and rheuniens nuclei, lateral hypothalamus, locus coeruleus, grey substance of the pons, reticular formation of medulla oblongata, inferior olivary complex, medial part of the nucleus of the solitary tract and nucleus of the spinal tract of the trigeminal nerve. An ultradian rhythm is found in the medial and lateral preoptic areas, in the medial hypothalamus, in the medial and in the lateral nuclei of habenula. No significant variations during 24 hr according to the Cosinor analysis are found in the dorsal and lateral cerebral cortex, striatum, globus pallidus, bed nucleus of the stria terminalis, septal nuclei, lateral nucleus of the thalamus, cochlear nuclei, nucleus of the solitary tract, lateral and caudal parts, dorsal motor nucleus of the vagal nerve, XII and IX nerve nuclei. The amplitude of the daily variations observed ranges from 10 to 40%. Our results demonstrate the high anatomical selectivity of the daily modifications of 3H-naloxone binding sites in the rat CNS. They also indicate that quantitative autoradiography is a suitable and sensitive technique for these studies.
内源性阿片肽、阿片受体以及几种相关行为，如阿片介导的镇痛作用，在包括大鼠在内的不同动物物种中呈现出每日变化。由于阿片类物质分布非常不均匀，试图将中枢神经系统（CNS）中阿片受体的每日节律与阿片相关的节律现象联系起来需要一种具有高解剖分辨率的实验方法。在本文中，我们通过定量放射自显影技术展示了成年雄性大鼠大脑不同区域3H-纳洛酮结合位点的每日变化研究。在一天中的每个调查时间点（0200、0600、1000、1400、1800和2200）处死5只大鼠。配体为3H-纳洛酮（4 nM），通过密度测定程序（图像分析仪Tesak VDC 501、计算机Digital PDP 11、3H微量天平）进行定量。根据单余弦分析方法以及方差分析后进行邓肯多重极差检验进行统计分析。我们分析了大鼠中枢神经系统的33个不同区域，阿片受体的每日变化具有区域选择性。在前扣带回皮质、海马皮质、丘脑室周核、内侧核、腹侧核、网状核和后核、菱形核、胶状核和Reuniens核、外侧下丘脑、蓝斑、脑桥灰质、延髓网状结构、下橄榄复合体、孤束核内侧部分和三叉神经脊束核中发现了昼夜节律。在视前内侧区和外侧区、下丘脑内侧区、缰核内侧核和外侧核中发现了超日节律。根据余弦分析，在大脑背侧和外侧皮质、纹状体、苍白球、终纹床核、隔核、丘脑外侧核、耳蜗核、孤束核、外侧和尾部、迷走神经背运动核、第 XII 和第 IX 脑神经核中，24小时内未发现显著变化。观察到的每日变化幅度在10%至40%之间。我们的结果证明了大鼠中枢神经系统中3H-纳洛酮结合位点每日变化的高解剖选择性。它们还表明定量放射自显影是进行这些研究的合适且灵敏的技术。
