Response of cerebral endothelial cells to hypoxia: modification by fructose-1,6-bisphosphate but not glutamate receptor antagonists.
Damage to the cerebral endothelium from ischemia could exacerbate brain injury by altering vascular integrity, but little is known concerning the response of cerebral endothelial cells to hypoxia. To address this issue, cerebral capillary endothelial cells were isolated from 14-day-old rats, grown to confluence, and placed in hypoxic chambers for up to 62 h. Cells were undamaged by 24 hours of hypoxia as assessed by lactate dehydrogenase release and ethidium bromide staining, but 48 h resulted in marked damage. Hypoxia was probably exacerbated by hypoglycemia because glucose levels fell to < 1 mM by 24 h, at which point ATP levels began to fall in hypoxic cultures (3.25 +/- 1.48 nmol/mg protein; mean +/- S.D.) relative to normoxic cultures (9.52 +/- 1.41 nmol/mg protein). Cells treated with 4 mM fructose-1,6-bisphosphate (FBP) had significantly less damage at 48 h of hypoxia than controls. FBP had little effect on rate of glucose depletion from the media, but ATP depletion due to hypoxia was significantly less. Thus, the protective effect of FBP may be mediated by the ability of treated cells to maintain higher ATP levels. Unlike FBP, glutamate receptor antagonists including MK-801, NBQX, DNQX, and kynurenic acid were ineffective in ameliorating hypoxia-induced endothelial cell injury.
Gobbel
G T
GT
Department of Neurology, University of California, San Francisco 94143.
Chan
T Y
TY
Gregory
G A
GA
Chan
P H
PH
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D002560:Cerebrovascular Circulation / Q000187:drug effects; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D004996:Ethidium; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology*; D005260:Female; D005635:Fructosediphosphates / Q000494:pharmacology*; D000860:Hypoxia / Q000378:metabolism* / Q000473:pathology; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D013194:Staining and Labeling
D018691:Excitatory Amino Acid Antagonists; D005635:Fructosediphosphates; D000255:Adenosine Triphosphate; D007770:L-Lactate Dehydrogenase; D004996:Ethidium; C029063:fructose-1,6-diphosphate