Abstract
Purpose: :
We have provided the evidence that not only excess evaporation of tear fluid but also hypofunction of the lacrimal gland contributes to the pathogenesis of VDT-associated dry eye (Plos one 2010). Calorie restriction extends life span and retards age-related chronic diseases including cancer, atherosclerosis, and dry eye. In this study we investigate the effect of intermittent fasting, reduced meal frequency, on lacrimal function in VDT associated dry eye using rat model.
Methods: :
8-week-old female Sprague-Dawley rats were used for this study. A series of treatments were performed under continuous exposure to low-humidity airflow (25 ± 5%, 2 - 4 m/s). Rats were placed on a swing made of a plastic pipe for 7.5 h/d, and for 16.5 hours, they were placed in individual cages without swing treatment. This series of treatments was repeated for up to 10 days. Rats were assigned to two groups: AL, ad libitum-fed animals, and IF, intermittent fasting rats, which were provided unlimited access to food every other day. The effect of AMP-activated protein kinase (AMPK) activation, energy sensor protein, in lacrimal gland were analyzed by Western blotting with antibodies against AMPK and Phospho-AMPK .
Results: :
A significant decrease in tear secretion was observed in the AL compared with the initial value. In the IF, singnificant improvement was observed in tear secretion by swing compared with AL. AMPK activity was apparently increased in IF compared to AL.
Conclusions: :
These data demonstrate that VDT-associated dry eye can be modified by diet manipulation. And AMPK signaling may play an important role of tear secretion which can be improved by IF .