Abstract
Purpose :
To examine the association between the levels of aldose reductase (AR) in rat lens epithelial cells (LECs) and the progression of the sugar cataract in streptozotocin (STZ) induced diabetic cataract model rats with different levels of hyperglycemia.
Methods :
Hyperglycemia was induced by the intraperitoneally injection of STZ (0.1 mg/g body weight) in 3 weeks Sprague-Dawley rats. Rats were divided into 3 groups in accordance with the amount of blood sugar (BS), mild (200-300 mg/dl), moderate (300-400 mg/dl), and severe (400 mg/dl over) BS groups. LECs with lens capsule was obtained and the amount of AR was analyzed by Western blots. The amount of polyol in whole lens was measured by liquid-gas chromatography.
Results :
There was a significant positive correlation between the blood glucose level and the degree of the cataract (p=0.0015, Spearman’s rank correlation), and AR inhibitor inhibited the progression of cataract. The result of Western blot showed the levels of AR expression of LECs was variables among individuals of rats approximately 0.7~1.2 folds. A significant correlation between the degree of cataract and AR levels was seen in the group of rats with mild BS group (p=0.016), but not in those with moderate (p=0.853) and severe (p=0.291) BS groups. Also, a significant correlation between the levels of polyol and AR expression was seen in the group of rats with mild BS group (p=0.046), but not in those with moderate (p=0.971) and severe (p=0.873) BS group.
Conclusions :
The increased level of AR expression was the risk factor of the progression of sugar cataract under hyperglycemia. Under the condition of severe hyperglycemia, polyol accumulation and the formation of cataract were progressed regardless of AR levels.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.