1Department of Neurology, Third Xiangya Hospital, Central South University, Changsha   410013, Hunan Province, China

2Department of Neurology, Second Xingya Hospital, Central South University, Changsha   410011, Hunan Province, China

Qiuyun Tu☆, Doctor, Associate professor, Department of Neurology, Third Xiangya Hospital, Central South University, Changsha   410013, Hunan Province, China Tu QY, Tang XQ, Zhao LL, Zi XH. Endothelin-3 and glial fibrillary acidic protein expression in the frontal and parietal cortex of type-2 diabetic mice following ischemia-reperfusion injury. Neural Regen Res 2008;3(6):638-41

Abstract

BACKGROUND: Patients with type-2 diabetes mellitus exhibit higher levels of plasma endothelin-1 (ET-1). However, very few reports exist regarding altered endothelin-3 (ET-3) and ET-1 concentrations in brain tissue.

OBJECTIVE: To observe expression changes of ET-3 and glial fibrillary acidic protein (GFAP) in the frontal and parietal cortex of type-2 diabetic mice following ischemia-reperfusion injury, with various reperfusion durations.

DESIGN, TIME AND SETTING: Randomized controlled animal study. The experiment was conducted in the Xiangya Medical College of Central South University and the Third Xiangya Hospital between February 2002 and January 2003.

MATERIALS: Sixty-six, adult, male, Kunming mice, weighing (30 ± 5) g, as well as rabbit anti-ET-3 polyclonal and rabbit anti-GFAP polyclonal antibodies, were provided by the Neurobiology Institute of Second Military Medical University in Japan.

METHODS: Sixty-six mice were randomly divided into five groups: diabetes mellitus (DM, n = 6), diabetes mellitus with ischemia-reperfusion (DM/IR, n = 24), ischemia-reperfusion (IR, n = 24), sham operation (SO, n = 6), and control (n = 6).

MAIN OUTCOME MEASURES: Following ischemia-reperfusion for 1, 3, 5, and 10 days, respectively, expression of ET- 3 and GFAP was immunohistochemically measured in the frontal and parietal cortex.

RESULTS: All 66 mice were included in the final result analysis. In the IR and DM/IR groups, ET-3- and GFAP-positive neurons increased in the frontal and parietal cortex in response to one day reperfusion, peaked at five days, and decreased at 10 days. ET-3 and GFAP expression was significantly greater in the DM/IR group after reperfusion for 1 day compared to the IR group. However, at other time points, there were no significant differences between the two groups.

CONCLUSION: Brain ischemia-reperfusion injury results in overexpression of ET-3 and activation of astrocytes. Diabetes increases the number of ET-3- and GFAP-positive astrocytes in brain tissue of ischemia-reperfusion mice with the same reperfusion duration.

Key Words: diabetes mellitus; brain ischemia-reperfusion; endothelin-3; glial fibrillary acidic protein

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