Endothelin-1 (ET-1) is a potent vasoconstrictor peptide implicated in retinal venous pathologies such as diabetic retinopathy and retinal vein occlusion.
Long-standing clinical course of DR; medication with insulin, sulfonylurea, or ACE inhibitors; and serum creatinine levels are factors possibly associated with changes in ET-1 expression in PBMCs.
A higher frequency of the Asn/Asn genotype of EDN1 was found in individuals with at least 10 years of diabetes and no retinopathy (controls) compared with DR patients with any duration of diabetes (DR: 2.3%; control: 11.0%; p=0.0002).
Polymorphic variability in the EDN1 and NOS3 genes does not appear to have a major impact on determining susceptibility or resistance to diabetic retinopathy.