Tapp W N, Natelson B H, Khazam C, Ottenweller J E
Physiol Behav. 1987;40(2):243-6. doi: 10.1016/0031-9384(87)90214-9.
In a prior experiment, we showed that living in constant light prolonged the lives of cardiomyopathic (CM) hamsters dying of heart failure. One possible explanation for this therapeutic effect related to the physiological effects of living in short and long days. The control hamsters for our constant light experiment lived in light/dark 12:12, a short day regimen which produces inhibitory effects on the gonadal function of healthy hamsters. To see whether the CM hamster responded to short days like healthy hamsters, we measured gonadal and seminal vesicle mass and plasma testosterone at 1 year of age in CM hamsters raised in the 2 light conditions and assessed testicular size repeatedly over the lives in a second group of hamsters raised in the 2 light conditions. As in healthy hamsters, we found gonadal function in CM hamsters to be greatly inhibited by LD 12:12. Importantly, we replicated our finding that living in constant light prolongs the life of CM hamsters in heart failure. We also found that the stress and trauma inherent in our repeatedly using surgery to assess testicular size acted as an additional risk factor controlling the lifespan of these animals. Our findings suggest that a photoperiodic effect of day length should be considered as one possible explanation of the mechanism of prolongation of life produced in hamsters with heart failure by constant light.
在之前的一项实验中，我们发现持续光照可延长因心力衰竭而死亡的心肌病（CM）仓鼠的寿命。对于这种治疗效果，一种可能的解释与短日照和长日照的生理效应有关。我们持续光照实验中的对照仓鼠生活在12小时光照/12小时黑暗的环境中，这是一种短日照方案，会对健康仓鼠的性腺功能产生抑制作用。为了探究CM仓鼠是否像健康仓鼠一样对短日照有反应，我们测量了在两种光照条件下饲养的1岁CM仓鼠的性腺和精囊质量以及血浆睾酮水平，并在另一组在两种光照条件下饲养的仓鼠的一生中反复评估睾丸大小。与健康仓鼠一样，我们发现12小时光照/12小时黑暗（LD 12:12）极大地抑制了CM仓鼠的性腺功能。重要的是，我们重复了之前的发现，即持续光照可延长心力衰竭CM仓鼠的寿命。我们还发现，我们反复使用手术来评估睾丸大小所带来的压力和创伤，成为了控制这些动物寿命的另一个风险因素。我们的研究结果表明，日照时长的光周期效应应被视为持续光照延长心力衰竭仓鼠寿命机制的一种可能解释。
