Higuchi Akon, Watanabe Toru, Matsubara Yoshihisa, Matsuoka Yuki, Hayashi Shizue
Department of Applied Chemistry, Seikei University, 3-3-1 Kichijoji Kitamachi, Musashino, Tokyo 180-8633, Japan.
J Phys Chem B. 2005 Jun 2;109(21):11033-6. doi: 10.1021/jp0508554.
The effect of neurite outgrowth of PC12 cells on collagen-coated glass plates under intermittent light irradiation at 525 nm and 0.4 mW/cm2 of intensity was investigated. Neurite outgrowth of PC12 cells was significantly suppressed when PC12 cells were cultivated under intermittent light irradiation with a total irradiation time of more than 2 min/h. No temperature increase was observed in the culture medium under either continuous or intermittent light irradiation. Therefore, suppression of neurite outgrowth under light irradiation was not due to the increase of temperature in the culture medium, but rather the effect of light on the PC12 cells, especially the signal transmittance of light to PC12 cells. The light irradiation interval also affected the neurite outgrowth of PC12 cells when the total irradiation time was constant. A high extension ratio of neurite outgrowth was observed under a long time interval of nonirradiation between light irradiations (1 min of irradiation every hour) as compared with frequent light irradiation intervals (5 s of irradiation every 5 min) with the same total irradiation period per hour. The neurite outgrowth ratio was thought to be dependent on the light intensity, the total time of light irradiation in the intermittent light irradiation, and the interval of light irradiation in the intermittent light irradiation.
研究了在525nm波长、强度为0.4mW/cm²的间歇光照射下，PC12细胞在胶原包被的玻璃板上的神经突生长情况。当PC12细胞在总照射时间超过2分钟/小时的间歇光照射下培养时，其神经突生长受到显著抑制。在连续或间歇光照射下，培养基中均未观察到温度升高。因此，光照射下神经突生长的抑制不是由于培养基温度升高，而是光对PC12细胞的作用，特别是光向PC12细胞的信号传递。当总照射时间恒定时，光照射间隔也会影响PC12细胞的神经突生长。与每小时总照射时间相同但光照射间隔频繁（每5分钟照射5秒）相比，在光照射之间的非照射时间间隔较长（每小时照射1分钟）的情况下，观察到神经突生长的延伸率较高。神经突生长率被认为取决于光强度、间歇光照射中的总光照射时间以及间歇光照射中的光照射间隔。
