Refined carbohydrates affect blood pressure and retinal vasculature in spontaneously hypertensive and Wistar-Kyoto rats

Abstract

Spontaneously hypertensive (SHR) and Wistar-Kyoto (WKY) rats received diets differing in amount and source of carbohydrates (CHO). When the CHO was in excess and the source was refined sugar or starch rather than natural ingredients, blood pressure (BP) rose, more so in SHR. This BP increase was observed whether sucrose, glucose, fructose or starch was the principal CHO. Increased urinary excretion of norepinephrine, dopamine and epinephrine also occurred. After only 2-3 months retinal capillary basement membrane damage was demonstrated in SHR and WKY rats ingesting large amounts of sucrose. No similar changes occurred on a high-starch diet. The damage consisted of thickening of capillary basement membranes, loss of homogeneity, and debris inclusions. These results suggest: that high dietary ingestion of CHO in the form of refined CHO augments BP in SHR and WKY rats via increased catecholamine production and/or release, and that the temporally foreshortened experimental period offered by the SHR/WKY model may be valuable in the study of diet-induced retinopathies.