Characterization of retinal vascular abnormalities in lean and obese spontaneously hypertensive rats

1. The obese SHR (Koletsky rat; SHR-k) is a unique animal model for the study of microvascular changes associated with genetic obesity, spontaneous hypertension, endogenous hyperlipidaemia, and hyperinsulinaemic, non-insulin dependent diabetes mellitus (Type II). 2. Lean and obese SHR-k exhibit retinal vascular changes which have not been previously characterized and are more severe than previously described in other animal models of experimental hypertension or non-insulin dependent diabetes. 3. Progressive retinal capillary dropout, capillary cell changes, vascular tortuosity and dilatation are severe. Vessels form elevated varicose vascular tortuosities which leak fluorescein dye and which are more frequent in the obese SHR-k. This study suggests that lean and obese SHR may be unique models for the study of multivariate factors in the pathogenesis of ischaemic neovascular proliferation.