title: Effects of melatonin on streptozotocin-induced retina neuronal apoptosis in high blood glucose rat.
abstract: One of the main pathological symptoms of early diabetic retinal neuropathy is retina neuronal apoptosis. In the present work we investigated the effects of indoleamine hormone melatonin, a powerful free radical scavenger, on streptozotocin-induced retina neuronal cell apoptosis in high blood glucose rat. After melatonin treatment (10 mg/kg/day), tunel detection was used to monitor the apoptosis rate of neurons in the retinal ganglion cell layer; reversed quantitative PCR was used to measure the mRNA expression of retinal caspase-3, Mn superoxidase dismutase (SOD) and Cu-Zn SOD; and the activities of total SOD (T-SOD) and sub-type SOD was detected using xanthine oxidase enzymatic detection. Our data showed that melatonin treatment leads to a decrease of retinal cell apoptosis and the apoptotic index was (1.67 ± 0.54) % and (7.73 ± 0.95) % at 8 and 12 weeks after treatment. The relative quantitative (RQ) value for caspase-3 mRNA expression was (6.996 ± 1.192) and (7.267 ± 1.178) in melatonin group, which are much lower than the values of diabetic group (12.566 ± 2.272 and (14.297 ± 2.110) at 8 and 12 weeks, respectively) under the same condition. mRNA expression of Mn SOD and Cu-Zn SOD as well as their activities all decreased in the diabetic group compared with the control group. While melatonin treatment induced the expression of Mn SOD mRNA and a continual increase of Mn SOD activity as well as the activity and mRNA expression of Cu-Zn SOD at 12 weeks. Therefore, our results demonstrate that melatonin treatment prevented the decrease in mRNA expression of SOD and the increase in caspase-3 mRNA expression induced by diabetes thus exerts a beneficial effect on retina neuronal apoptosis.
authors.affiliation: Department of Ophthalmology, The First Hospital Affiliated to PLA General Hospital, Fucheng Road 51, Haidian District, Beijing, 100048, People's Republic of China.
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Li
authors.forename: Maonian
authors.initials: M
authors.lastname: Zhang
authors.forename: Weiqiang
authors.initials: W
authors.lastname: Tang
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D001786:Blood Glucose / Q000378:metabolism*; D053148:Caspase 3 / Q000235:genetics; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism / Q000473:pathology; D008297:Male; D008550:Melatonin / Q000494:pharmacology*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012160:Retina / Q000187:drug effects / Q000473:pathology*; D013311:Streptozocin / Q000494:pharmacology*; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D001786:Blood Glucose; D012333:RNA, Messenger; D013311:Streptozocin; D013482:Superoxide Dismutase; D053148:Caspase 3; D008550:Melatonin