Fig. 3
Retinal hydrogen sulfide levels and oxidative stress markers in diabetic retinopathy. Retinal homogenate was used to measure (a) H2S levels spectrophotometrically at 670 nm using N-dimethyl-p-phenylenediamine sulfate, and (b) GSH levels by an enzymatic recycling method. (c) Gene transcripts of CYTB were quantified in retinal microvessels by q-RTPCR to estimate mtDNA damage. Each measurement was made in duplicates in 5–7 samples each in nondiabetic control (Norm) and diabetic retinopathy (DR) groups. The values obtained from nondiabetic controls are considered as one. *p < 0.05 compared with nondiabetic donors