Atrial natriuretic peptide in the vitreous humor and epiretinalmembranes of patients with proliferative diabetic retinopathy

[摘要] Purpose: Atrial natriuretic peptide (ANP) has been recentlydescribed as an endogenous inhibitor of the synthesis and angiogenicaction of vascular endothelial growth factor (VEGF). Given VEGF's keyrole in promoting neovascularization in proliferative diabeticretinopathy (PDR), this study was designed to evaluate the possibilitythat ANP could be involved in the neovascular and fibrotic complicationsof PDR.Methods: We determined ANP by radioimmunoassay in plasma andvitreous humor samples collected from diabetic patients with and withoutPDR and from non-diabetic subjects. ANP was also immunohistochemicallylocalized in the epiretinal membranes of patients with PDR.Results: Vitreous ANP concentrations were significantly higher inpatients with active PDR compared to patients with quiescent PDR,diabetes without PDR or controls <0.05. Significant differences werealso observed between vitreous ANP levels in diabetic patients withoutPDR and control subjects. There was no significant correlation betweenserum and vitreous ANP levels in any of the patient groups. ANP wasdetected in the fibrovascular epiretinal tissue of patients with PDR.Conclusions: Diabetic patients with active neovascularization havesignificantly higher levels of ANP in the vitreous humor than thosewithout active PDR. Diabetic patients without PDR were also found tohave significantly higher vitreous ANP levels than non-diabeticpatients. Since plasma and vitreous ANP concentrations were found to beunrelated, we suggest intraocular ANP synthesis and/or an increase inthe release of ANP into the vitreous, as opposed to diffusion from theblood, as the main factors contributing to the high vitreous ANP levelsobserved in diabetic patients. In the fibrovascular epiretinal tissue ofthese patients, ANP was found to be localized in vascular, glial,fibroblast-like and retinal pigment epithelium cells. Our findingssuggest a role for ANP in PDR.

[学科分类] 生物化学/生物物理