Electrophysiological Findings in a Murine Model of Diabetes

Abstract

Abstract: : Purpose: To evaluate retinal function in a hyperlipidemic insulin-resistant murine model of diabetes (ApoE-/- db/db) by electroretinography. Methods: Electroretinograms (ERGs) were performed on age-matched, 6 to 9 month old, littermate, overnight dark-adapted hyperlipidemic hyperglycemic mice (ApoE-/- db/db; HLHG) (n=14), hyperlipidemic normoglycemic controls (ApoE -/- db/m; HLNG) (n=11) and normolipidemic normoglycemic wild type mice (ApoE+/+ db/m; NLNG) (n=18) under anesthesia. A and B wave amplitude and latencies were recorded. The amplitudes and implicit times of oscillatory potentials OP1, OP2 and OP3 were measured. Body temperature was maintained using a variable heating stage. Results: B-wave latency was increased in the ApoE-/- db/db mice (mean±SD, 34.45±2.86) compared to the wild-type age matched littermate controls (mean±SD, 31.99±2.04; p=0.008). OP1 (p=0.036), OP2 (p= 0.02) and OP3 (p=0.04) implicit times were similarly affected. The OP1 amplitude also showed a statistically significant decrease (p=0.016). The other parameters studied were not found to be significantly different. Hyperlipidemia alone studied in the ApoE-/- db/m mice did not appear to induce statistically significant differences in any of the parameters recorded and studied. Conclusions: B-wave, OP1, OP2 and OP3 implicit times were significantly increased in the HLHG (ApoE-/- db/db) mouse when compared to NLNG (ApoE +/+ db/m). These data suggest that this murine model of diabetes display electroretinographic changes of diabetic retinopathy. We are presently comparing these results with data from the db/db animal model.

Keywords: diabetic retinopathy • electroretinography: non-clinical • animal model