Stimulation of Alpha-1-Adrenergic Receptor Ameliorates Obesity-Induced Cataracts by Activating Glycolysis and Inhibiting Cataract-Inducing Factors

Abstract

Background: Obesity, the prevalence of which is increasing due to the lack of exercise and increased consumption of Westernizeddiets, induces various complications, including ophthalmic diseases. For example, obesity is involved in the onset of cataracts. Methods: To clarify the effects and mechanisms of midodrine, an α1-adrenergic receptor agonist, in cataracts induced by obesity, weconducted various analytic experiments in Otsuka Long-Evans Tokushima Fatty (OLETF) rats, a rat model of obesity. Results: Midodrine prevented cataract occurrence and improved lens clearance in OLETF rats. In the lenses of OLETF rats treatedwith midodrine, we observed lower levels of aldose reductase, tumor necrosis factor-α, and sorbitol, but higher levels of hexokinase,5’-adenosine monophosphate-activated protein kinase-alpha, adenosine 5´-triphosphate, peroxisome proliferator-activated receptordelta, peroxisome proliferator-activated receptor gamma coactivator 1-alpha, superoxide dismutase, and catalase. Conclusion: The ameliorating effects of midodrine on cataracts in the OLETF obesity rat model are exerted via the following threemechanisms: direct inhibition of the biosynthesis of sorbitol, which causes cataracts; reduction of reactive oxygen species and inflammation; and (3) stimulation of normal aerobic glycolysis.