Morphological analysis of the retina in salt-loaded KK-Ay mice, obese and type 2 diabetic model

Abstract

Retinopathy, one of the microvascular complications in diabetes, can cause blindness. Salt-loading is known to exacerbate microvascular damage and may affect retinopathy. In this study, we investigated the effect of salt loading on early lesions of diabetic retinopathy. Male C57BL/6 and KK-Ay mice were salt-loaded with 1% sodium chloride (NaCl)-containing drinking water for 12 weeks. In addition, to determine the effects of high fat and high sucrose, a high fat/high sucrose diet was also fed to the 1% NaCl-loaded group of mice of both strains. Retinal thickness was measured at an arbitrary location from the optic nerve disc, and thinning of the retina was observed in KK-Ay mice compared to C57BL/6 mice. Salt-loading caused retinal thinning in C57BL/6 mice, but not in KK-Ay mice. In KK-Ay mice, the effect of salt-loading may have been masked by the effects of obesity and diabetic status during this experimental period. There was also a small effect of QF on the retina, suggesting that dietary components other than salt loading may affect retinopathy.