Abdel Gawad F A, El-Shaarawy E A A, Arsanyos S F, Abd El-Galil T I, Awes G N
Department of Anatomy and Embryology, Faculty of Medicine, Cairo University, Cairo, Egypt.
Folia Morphol (Warsz). 2019;78(2):297-306. doi: 10.5603/FM.a2018.0073. Epub 2018 Aug 14.
Through scientific literature, there is evidence that light affects thyroid function in human, mice and rabbits. Constant light and sleep deprivation is also used as a form of human torture, as it has impact on cognitive performances. The present work was conducted to study the effect of constant light for short and long periods on the thyroid gland in the prepubertal male albino rats.
A total of 30 prepubertal male albino rats were used. The rats separated into three groups: group I (control); group II were those rats put under steady encompassing light (24 h/day, light intensity of 600 lux) for 4 weeks; and group III were the rats maintained in constant light for 3 months. The rat thyroid gland was subjected to histological and ultrastructural examination.
The rats exposed to light for long durations showed disturbed architecture; the follicles exhibited back to back arrangement (signs of hypertrophy with hyperplasia), lined by multiple layers of follicular cells or were lined by vacuolated cells. Few thyroid follicles exhibited cystic hyperplasia. Congested blood capillaries were demonstrated between the follicles.
It can be concluded that the short-term exposure to constant light for 1 month had no apparent effect on thyroid gland tissues while longer exposure to light for 3 months had detrimental effects on the thyroid gland structure of male albino rats.
通过科学文献可知，有证据表明光照会影响人类、小鼠和兔子的甲状腺功能。持续光照和睡眠剥夺也被用作一种折磨人的方式，因为它会影响认知能力。本研究旨在探讨短期和长期持续光照对青春期前雄性白化大鼠甲状腺的影响。
总共使用了30只青春期前雄性白化大鼠。将大鼠分为三组：第一组（对照组）；第二组是置于稳定的环境光照（24小时/天，光照强度600勒克斯）下4周的大鼠；第三组是在持续光照下饲养3个月的大鼠。对大鼠的甲状腺进行组织学和超微结构检查。
长期暴露于光照下的大鼠甲状腺结构紊乱；滤泡呈现背靠背排列（肥大伴增生的迹象），由多层滤泡细胞衬里或由空泡化细胞衬里。少数甲状腺滤泡呈现囊性增生。滤泡之间可见充血的毛细血管。
可以得出结论，短期（1个月）持续光照对甲状腺组织无明显影响，而长期（3个月）光照对雄性白化大鼠的甲状腺结构有有害影响。
