Rod phototransduction and light signal transmission during type 2 diabetes [article]

Silke Becker, Frans Vinberg
2020 bioRxiv   pre-print
Diabetic retinopathy is a major complication of diabetes recently associated with attenuated photoreceptor function. Multiple stressors in diabetes, such as hyperglycemia, oxidative stress and inflammatory factors, have been identified, but systemic effects of diabetes on outer retina function are incompletely understood. Ex vivo ERG presents the unique opportunity to test rod photoreceptor light signal transduction and transmission and determine whether they are permanently compromised and/or
more » ... compromised and/or adapt to hyperglycemia in chronic type 2 diabetes. Light-evoked rod photoreceptor signals in control and diabetic mice in vivo were compared to those recorded ex vivo under normal or elevated extracellular glucose. Transduction and transmission of light signals were compromised in 6 mo. diabetic mice in vivo. In contrast, ex vivo rod signaling was similar in isolated retinas from 6 mo. control and diabetic mice under normoglycemic conditions. Acutely elevated glucose ex vivo increased light-evoked photoreceptor responses in control mice, but did not affect light responses in diabetic mice. In summary, our data suggest that long-term diabetes does not irreversibly change the ability of rod photoreceptors to transduce and mediate light signals. However, type 2 diabetes appears to induce adaptational changes in the rods that render them less sensitive to increased availability of glucose.
doi:10.1101/2020.01.14.905265 fatcat:62etch5qcvfhzayq4deg7laszu