Spessert R, Rapp M
Department of Anatomy, Johannes Gutenberg University, Mainz, Germany.
Neuroreport. 2001 Mar 26;12(4):781-5. doi: 10.1097/00001756-200103260-00033.
The photoneural regulation of nitric oxide synthase type I (NOS I) expression in the rat pineal was investigated using semiquantitative RT-PCR. NOS I transcript expression exhibited a daily rhythm with peak values during the night hours. The daily rhythm in NOS I transcript expression persisted under constant dark conditions and was abolished under constant light conditions. The extent of nocturnal NOS I expression was found to be dependent on the photoperiod. It was attenuated under 20 h light and 4 h dark (L:D 20:4) compared with 12 h light and 12 h dark (L:D 12:12). The present findings indicate that, in the rat pineal, NOS I transcript expression exhibits a true circadian rhythm. Further, photoperiod-induced changes in circadian transcript expression appear to be responsible for reported changes in NOS I protein expression.
利用半定量逆转录聚合酶链反应（RT-PCR）研究了大鼠松果体中I型一氧化氮合酶（NOS I）表达的光神经调节。NOS I转录本表达呈现出每日节律，在夜间达到峰值。NOS I转录本表达的每日节律在持续黑暗条件下持续存在，而在持续光照条件下消失。发现夜间NOS I表达的程度取决于光周期。与12小时光照和12小时黑暗（L:D 12:12）相比，在20小时光照和4小时黑暗（L:D 20:4）条件下其表达减弱。目前的研究结果表明，在大鼠松果体中，NOS I转录本表达呈现出真正的昼夜节律。此外，光周期诱导的昼夜转录本表达变化似乎是导致报道的NOS I蛋白表达变化的原因。
