Rollag M D, Welsh M G, Klein D C
J Pineal Res. 1984;1(4):339-47. doi: 10.1111/j.1600-079x.1984.tb00224.x.
This report describes the response of both the superficial and deep components of the gerbil pineal gland to a 30-min pulse of fluorescent light at the time of the nocturnal peak in pineal activity. When gerbils were maintained in a 14 h light:10 h dark photoperiod, mean melatonin concentrations in the superficial pineal gland ranged between 72 and 108 pg/gland during the day and first 4 h of darkness, rose to a peak of 399 pg/gland 7 h after lights out, then returned to basal levels at the expected time of light onset. Pineal melatonin contents were reduced to daytime values within 30 min after exposure of gerbils to fluorescent light at the time of the nocturnal peak. These changes in superficial pineal melatonin content reflected the circadian pattern in serotonin N-acetyltransferase (NAT) activity, as would be expected if NAT controls melatonin synthesis. In addition to the reductions in NAT and melatonin content induced by nocturnal photic stimulation, there was a 30% reduction in mean pinealocyte nuclear volume. A nocturnal elevation in melatonin content but not in NAT activity occurred in the deep pineal gland. Unlike the superficial pineal gland, the deep pineal gland did not demonstrate a response in melatonin content, NAT activity, or pinealocyte nuclear volumes upon exposure of gerbils to light at the time of the nocturnal peak in superficial pineal activity.
本报告描述了沙鼠松果体浅层和深层成分在松果体活动夜间峰值时对30分钟荧光脉冲的反应。当沙鼠饲养在14小时光照：10小时黑暗的光周期中时，白天和黑暗开始后的前4小时，浅层松果体中褪黑素的平均浓度在72至108 pg/腺体之间，在熄灯后7小时升至399 pg/腺体的峰值，然后在预期的光照开始时间恢复到基础水平。在夜间峰值时将沙鼠暴露于荧光灯下30分钟后，松果体褪黑素含量降至白天的水平。浅层松果体褪黑素含量的这些变化反映了血清素N-乙酰转移酶（NAT）活性的昼夜节律模式，如果NAT控制褪黑素合成，这是可以预期的。除了夜间光刺激引起的NAT和褪黑素含量降低外，松果体细胞平均核体积减少了30%。深层松果体中褪黑素含量夜间升高，但NAT活性没有升高。与浅层松果体不同，当沙鼠在浅层松果体活动的夜间峰值时暴露于光下时，深层松果体在褪黑素含量、NAT活性或松果体细胞核体积方面没有表现出反应。
