Task: Answer Verification
Input (English): Question: Does blocking ET-1 receptors correct subnormal retinal oxygenation response in experimental diabetic retinopathy?
Answer: Because subnormal retinal DeltaPo(2) after drug treatment is a biomarker of subsequent vascular histopathology, the present data raise the possibility that retinal ET-1 does not play a key role in the pathogenesis of diabetic retinopathy.
Output (English): no