Schaad N C, Vanecek J, Schulz P E
Department of Psychiatry, Geneva University Medical School, Chêne-Bourg, Switzerland.
J Neurochem. 1994 Jun;62(6):2496-9. doi: 10.1046/j.1471-4159.1994.62062496.x.
We report here a photoneural regulation of nitric oxide synthase (NOS) activity in the rat pineal gland. In the absence of the adrenergic stimulation following constant light exposure (LL) or denervation, pineal NOS activity is markedly reduced. A maximal drop is measured after 8 days in LL. When rats are housed back in normal light:dark (LD) conditions (12:12), pineal NOS activity returns to normal after 4 days. A partial decrease in pineal NOS activity is also observed when rats are placed for 8 days in LD 18:6 or shorter dark phases, indicating that pineal NOS activity reflects the length of the dark phase. Because it is known that norepinephrine (NE) is released at night from the nerve endings in the pineal gland and this release is blocked by exposure to light, our data suggest that NOS is controlled by adrenergic mechanisms. Our observation may also explain the lack of cyclic GMP response to NE observed in animals housed in constant light.
我们在此报告大鼠松果体中一氧化氮合酶（NOS）活性的光神经调节。在持续光照（LL）或去神经支配后缺乏肾上腺素能刺激的情况下，松果体NOS活性显著降低。在LL条件下8天后可测得最大降幅。当大鼠重新置于正常光照：黑暗（LD）条件（12:12）下时，松果体NOS活性在4天后恢复正常。当大鼠在LD 18:6或更短黑暗期条件下放置8天时，也观察到松果体NOS活性部分降低，这表明松果体NOS活性反映了黑暗期的长度。由于已知去甲肾上腺素（NE）在夜间从松果体的神经末梢释放，且这种释放会被光照阻断，我们的数据表明NOS受肾上腺素能机制控制。我们的观察结果也可能解释了在持续光照环境下饲养的动物中未观察到对NE的环磷酸鸟苷反应的原因。
