Streptozotocin-induced diabetes causes astrocyte death after ischemia and reperfusion injury.
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.
Muranyi
Marianna
M
Department of Complementary and Alternative Medicine, John A. Burns School of Medicine, University of Hawaii, Honolulu, 96822, USA.
Ding
Chaonan
C
He
Qingping
Q
Lin
Yanling
Y
Li
Ping-An
PA
D000818:Animals; D001253:Astrocytes / Q000187:drug effects / Q000473:pathology* / Q000648:ultrastructure; D016923:Cell Death / Q000502:physiology*; D004249:DNA Damage; D003921:Diabetes Mellitus, Experimental / Q000139:chemically induced / Q000473:pathology*; D008264:Macrophages / Q000378:metabolism; D008297:Male; D009474:Neurons / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism; D018384:Oxidative Stress; D051381:Rats; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000473:pathology*; D013481:Superoxides / Q000378:metabolism
D013481:Superoxides; D009569:Nitric Oxide; D052247:Nitric Oxide Synthase Type II