Retinal dysfunction parallels morphologic alterations and precede clinically detectable vascular alterations in Meriones shawi, a model of type 2 diabetes

Autor: Mohamed Dogui, Riadh Messaoud, Imane Hammoum, Soumaya Amara, Rafika Ben Chaouacha-Chekir, Ridha Charfeddine, Rached Azaiz, Rim Kahloun, Maha Benlarbi, Ákos Lukáts, Moncef Khairallah, Ahmed Dellaa
Rok vydání: 2018
Předmět:
Blood Glucose
Male
0301 basic medicine
medicine.medical_specialty
genetic structures
Vesicular glutamate transporter 1
Type 2 diabetes
Retina
03 medical and health sciences
Cellular and Molecular Neuroscience
chemistry.chemical_compound
0302 clinical medicine
Internal medicine
Electroretinography
medicine
Animals
Scotopic vision
Fluorescein Angiography
Night Vision
Metabolic Syndrome
Diabetic Retinopathy
Color Vision
medicine.diagnostic_test
biology
business.industry
Body Weight
Retinal Vessels
Retinal
Diabetic retinopathy
medicine.disease
Fluorescein angiography
Immunohistochemistry
Sensory Systems
Disease Models
Animal
Ophthalmology
030104 developmental biology
Endocrinology
Diabetes Mellitus
Type 2
chemistry
030221 ophthalmology & optometry
biology.protein
sense organs
Gerbillinae
business
Erg
Tomography
Optical Coherence
Photopic vision
Zdroj: Experimental Eye Research. 176:174-187
ISSN: 0014-4835
Popis: Diabetic retinopathy is a major cause of reduced visual acuity and acquired blindness. The aim of this work was to analyze functional and vascular changes in diabetic Meriones shawi (M.sh) an animal model of metabolic syndrome and type 2 diabetes. The animals were divided into four groups. Two groups were fed a high fat diet (HFD) for 3 and 7 months, two other groups served as age-matched controls. Retinal function was assessed using full field electroretinogram (Ff-ERG). Retinal thickness and vasculature were examined by optical coherence tomography, eye fundus and fluorescein angiography. Immunohistochemistry was used to examine key proteins of glutamate metabolism and synaptic transmission. Diabetic animals exhibited significantly delayed scotopic and photopic ERG responses and decreases in scotopic and photopic a- and b-wave amplitudes at both time points. Furthermore, a decrease of the amplitude of the flicker response and variable changes in the scotopic and photopic oscillatory potentials was reported. A significant decrease in retinal thickness was observed. No evident change in the visual streak area and no sign of vascular abnormality was present; however, some exudates in the periphery were visible in 7 months diabetic animals. Imunohistochemistry detected a decrease in the expression of glutamate synthetase, vesicular glutamate transporter 1 and synaptophysin proteins. Results indicate that a significant retinal dysfunction was present in the HFD induced diabetes involving both rod and cone pathways and this dysfunction correlate well with the morphological abnormalities reported previously. Furthermore, neurodegeneration and abnormalities in retinal function occur before vascular alterations would be detectable in diabetic M.sh.
Databáze: OpenAIRE
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