Predicting Renal Damage in Salt-Sensitive Hypertensive Rats by Measuring Retinal Vascular Leukocyte Adhesion

Abstract

Purpose: : The correlation between hypertensive retinal leukocyte adhesion (leukostasis) and renal damage is unclear. In addition, in vivo kidney leukostasis measurements are not possible. Therefore, this study was performed to investigate whether retinal leukostasis in Dahl salt-sensitive hypertensive rats (Dahl) could be a surrogate marker for hypertensive renal damage.

Methods: : Four-week-old male Dahl were fed a normal salt (0.3% NaCl) or high salt (8% NaCl) diet. At 3 days, 1, 2, 3, and 4 weeks, retinal leukostasis was quantitatively determined using a scanning laser ophthalmoscope (SLO; Rodenstock, Ottobrunn, Germany). Kidney adhesion molecule mRNA was analyzed by semi-quantitative RT-PCR (n = 10, in each group). Additionally, control or anti-CD18 antibodies were administered to Dahl ones two days for 10 days (n = 6, in each group), and urinary protein was measured. Retinal leukostasis was determined after perfusion staining, and glomerular sclerosis was analyzed histologically.

Results: : Leukostasis in the high-salt diet group was significantly higher than the normal-salt diet group at all points. E-selectin and intercellular adhesion molecule-1 mRNA levels increased significantly in the kidney. Retinal leukostasis, glomerular sclerosis and urinary protein werre significantly suppressed by anti-CD18 antibody treatment. Instead of retinal minute vein leukostasis, retinal arterior leukostasis was correlated with glomerular sclerosis.

Conclusions: : Retinal leukostasis increased with salt loading and decreased with anti-CD18 antibody treatment in Dahl. The morphological changes in the kidney and retinal leukostasis were correlated, suggesting that hypertensive renal damage may be assessed by retinal blood vessels.

Keywords: retinal adhesion • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • cell adhesions/cell junctions