Streptozotocin-Induced Diabetes Causes Astrocyte Death After Ischemia and Reperfusion Injury

• DOI: 10.2337/diabetes.55.02.06.db05-0654
• Publication Date: 2006-06-01T23:03:17Z
• Authors: Marianna Muranyi; Chaonan Ding; QingPing He; Yanling Lin; Ping-An Li
• Keywords: Male; Neurons; Cell Death; Macrophages; Nitric Oxide Synthase Type II; Nitric Oxide; Diabetes Mellitus, Experimental; Rats; 3. Good health; Oxidative Stress; 03 medical and health sciences; 0302 clinical medicine; Superoxides; Astrocytes; Reperfusion Injury; Animals; Rats, Wistar; DNA Damage

Diabetes exacerbates neuronal cell death induced by cerebral ischemia. One contributing factor is enhanced acidosis during ischemia. Astrocytes are vulnerable to hypoxia under acidic conditions in vitro and may be targets of ischemia under diabetic conditions. The objective of this study was to determine whether diabetes would cause damage to astrocytes after an ischemic brain injury in vivo. Diabetic and nondiabetic rats were subjected to 5 min of forebrain ischemia and followed by 30 min, 6 h, or 1 or 3 days of recovery. The results showed that ischemia caused activation of astrocytes in nondiabetic rats. In contrast, diabetes caused astrocyte activation in early stage of reperfusion and astrocyte death in late stage of reperfusion. Remarkable astrocyte death was preceded by increased DNA oxidation. Further studies revealed that increased astrocyte damage coincided with enhanced production of free radicals. These data suggest that hyperglycemic ischemia worsens outcome in astrocytes, as it does in neurons.