Kilduff T S, Landel H B, Nagy G S, Sutin E L, Dement W C, Heller H C
Department of Psychiatry, Stanford University, CA 94305.
Brain Res Mol Brain Res. 1992 Nov;16(1-2):47-56. doi: 10.1016/0169-328x(92)90192-e.
Administration of the pineal hormone melatonin to rats induces expression of Fos, the protein product of the c-fos proto-oncogene, in the suprachiasmatic nucleus (SCN), the putative biological clock of mammals. Expression of the Fos protein is dependent on circadian phase: injections in the late subjective night (circadian time (CT) 22) induce Fos expression in cells within the ventral SCN whereas injections during the subjective day are ineffective. Since melatonin injections in the late subjective day have previously been shown to phase advance circadian rhythms, these results indicate that phase-advances of the circadian system can occur without increased expression of Fos protein in the SCN, at least at levels detectable by immunohistochemistry. In support of in situ hybridization histochemical evidence obtained previously, immunocytochemical data from vehicle-injected control rats suggest that the Fos protein undergoes an endogenous fluctuation with peak levels in the SCN occurring during the subjective night. These observations indicate that melatonin can affect immediate early gene expression within the SCN.
给大鼠注射松果体激素褪黑素会诱导原癌基因c-fos的蛋白质产物Fos在视交叉上核（SCN）中表达，视交叉上核被认为是哺乳动物的生物钟。Fos蛋白的表达取决于昼夜节律相位：在主观夜晚后期（昼夜时间（CT）22）注射会诱导腹侧SCN内细胞中的Fos表达，而在主观白天注射则无效。由于先前已表明在主观白天后期注射褪黑素会使昼夜节律提前，这些结果表明，昼夜节律系统的提前至少在免疫组织化学可检测的水平上可以在SCN中Fos蛋白表达未增加的情况下发生。为支持先前获得的原位杂交组织化学证据，来自注射溶剂对照大鼠的免疫细胞化学数据表明，Fos蛋白经历内源性波动，在主观夜晚期间SCN中出现峰值水平。这些观察结果表明，褪黑素可以影响SCN内的即刻早期基因表达。
