Nutritional Studies In Diabetic Cataract Prevention

Cataract has been defined as an opacity of the lens leading to loss of visual acuity. This study was designed to find biochemical tests to measure the level of cataractogenesis occurring, and to use these tests to examine the efficacy of various dietary additives in preventing or reducing diabetic cataract formation.;A method was developed for determining ATP levels in tissue by measuring light emission produced by was homogenized in 2 ml of 8 M guanidium chloride to stabilize the ATP.;A radioimmunoassay was developed for rat lens (gamma)-crystallin using antiserum raised in rabbits. (gamma)-Crystallin was separated from the other water-soluble proteins of the lens on a Sephacryl S-200 column and iodinated using Iodo-gen(\u27R).;Streptozotocin-diabetic female Wistar rats (180 - 260 g, 12 rats per group) received in their ground food one of the following: BHT at 0.067% or 0.50% w/w food, vitamin C at 0.3% or 1.0% w/w food, taurine at 0.05% or 0.10% w/w food, vitamin A at 6,250 iu or 12,500 iu/kg food, or vitamin E, vitamin E acetate, vitamin E succinate at 2,850 iu/kg food. The duration of the experiments for the groups receiving vitamin C and BHT was 10 weeks; for the groups receiving vitamin A, vitamin E, and taurine it was 6 weeks. Taurine was given 1 week after streptozotocin injection, all other treatments began the day of injection.;At the end of the experimental period, the rats were examined for general body condition and scored visually for cataract. After sacrifice, blood was collected for serum glucose, aqueous and vitreous humours for (gamma)-crystallin RIA, and lenses for ATP.;Diabetes led to a 5 to 6-fold increase in vitreous humour (gamma)-crystallin and a 2 to 3-fold increase in the aqueous humour. There was also a worsening in general body condition, weight loss, formation of cataract, and a 40-60% decrease in lens ATP.;Vitreous humour (gamma)-crystallin was reduced 40-60% with vitamin C, vitamin A, and BHT. Taurine and vitamin E gave reductions of 15-25%.;BHT and vitamin A improved the general body condition.;BHT, taurine, and vitamin E resulted in a weight gain.;Neither diabetes nor any treament affected the lens weights