PURPOSE: To investigate the oxidative status of albumin in the aqueous humor and serum of senile cataract patients with diabetes in order to clarify the pathogenesis of this condition. METHODS: High-performance liquid chromatography (HPLC) was employed to measure the reduced form of albumin (mercaptalbumin) and the oxidized form of albumin (nonmercaptalbumin) in serum and aqueous humor. The mercaptalbumin, nonmercaptalbumin-1, and nonmercaptalbumin-2 fractions in aqueous humor obtained at the start of cataract surgery and in serum obtained intraoperatively were analyzed by HPLC in 7 senile cataract patients with diabetic retinopathy (2 men and 5 women aged 70+/-9.8 years). RESULTS: The mean content (%) of mercaptalbumin, nonmercaptalbumin-1, and nonmercaptalbumin-2 in serum albumin from the diabetic patients was 60.3+/-7.8, 36.9+/-6.6, and 2.7+/-1.7%, respectively, while the corresponding values for aqueous humor albumin were 40.0+/-14.1, 52.4+/-12.6, and 7.5+/-3.6%. When the mercaptalbumin content (%) of aqueous humor albumin was compared between patients with active and inactive diabetic retinopathy, the respective values were 47.0+/-9.1% and 22.8+/-5.7%. A significant correlation mercaptalbumin content (%) of aqueous humor albumin did not show with the HbA1c level, but there was still a relationship (Y = 5.0 x - 2.7, r = 0.80, and p < 0.052). CONCLUSION: The increase of mercaptalbumin (the reduced form of albumin) in the aqueous humor of patients with diabetic retinopathy probably resulted from an increase of retinal vascular permeability.
PURPOSE: To investigate the oxidative status of albumin in the aqueous humor and serum of senile cataractpatients with diabetes in order to clarify the pathogenesis of this condition. METHODS: High-performance liquid chromatography (HPLC) was employed to measure the reduced form of albumin (mercaptalbumin) and the oxidized form of albumin (nonmercaptalbumin) in serum and aqueous humor. The mercaptalbumin, nonmercaptalbumin-1, and nonmercaptalbumin-2 fractions in aqueous humor obtained at the start of cataract surgery and in serum obtained intraoperatively were analyzed by HPLC in 7 senile cataractpatients with diabetic retinopathy (2 men and 5 women aged 70+/-9.8 years). RESULTS: The mean content (%) of mercaptalbumin, nonmercaptalbumin-1, and nonmercaptalbumin-2 in serum albumin from the diabeticpatients was 60.3+/-7.8, 36.9+/-6.6, and 2.7+/-1.7%, respectively, while the corresponding values for aqueous humor albumin were 40.0+/-14.1, 52.4+/-12.6, and 7.5+/-3.6%. When the mercaptalbumin content (%) of aqueous humor albumin was compared between patients with active and inactive diabetic retinopathy, the respective values were 47.0+/-9.1% and 22.8+/-5.7%. A significant correlation mercaptalbumin content (%) of aqueous humor albumin did not show with the HbA1c level, but there was still a relationship (Y = 5.0 x - 2.7, r = 0.80, and p < 0.052). CONCLUSION: The increase of mercaptalbumin (the reduced form of albumin) in the aqueous humor of patients with diabetic retinopathy probably resulted from an increase of retinal vascular permeability.