Chloride transport inhibitors influence recovery from oxygen-glucose deprivation-induced cellular injury in adult hippocampus.
Cerebral ischemia in vivo or oxygen-glucose deprivation (OGD) in vitro are characterized by major disturbances in neuronal ionic homeostasis, including significant rises in intracellular Na(+), Ca(2+), and Cl(-) and extracellular K(+). Recently, considerable attention has been focused on the cation-chloride cotransporters Na-K-Cl cotransporter isoform I (NKCC-1) and K-Cl cotransporter isoform II (KCC2), as they may play an important role in the disruption of ion gradients and subsequent ischemic damage. In this study, we examined the ability of cation-chloride transport inhibitors to influence the biochemical (i.e. ATP) and histological recovery of neurons in adult hippocampal slices exposed to OGD. In the hippocampus, 7 min of OGD caused a loss of ATP that recovered partially (approximately 50%) during 3 h of reoxygenation. Furosemide, which inhibits the NKCC-1 and KCC2 cotransporters, and bumetanide, a more specific NKCC-1 inhibitor, enhanced ATP recovery when measured 3 h after OGD. Furosemide and bumetanide also attenuated area CA1 neuronal injury after OGD. However, higher concentrations of these compounds appear to have additional non-specific toxic effects, limiting ATP recovery following OGD and promoting neuronal injury. The KCC2 cotransporter inhibitor DIOA and the Cl(-) ATPase inhibitor ethacrynic acid caused neuronal death even in the absence of OGD and promoted cytochrome c release from isolated mitochondria, indicating non-specific toxicities of these compounds.
Pond
Brooks B
BB
Department of Pharmacology and Cancer Biology, Duke University Medical Center, Box 3813, Durham, NC 27710, USA.
Galeffi
Francesca
F
Ahrens
Rebecca
R
Schwartz-Bloom
Rochelle D
RD
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D002545:Brain Ischemia / Q000473:pathology; D002034:Bumetanide / Q000494:pharmacology; D002352:Carrier Proteins / Q000037:antagonists & inhibitors*; D002470:Cell Survival / Q000187:drug effects; D002712:Chlorides / Q000378:metabolism*; D045304:Cytochromes c / Q000378:metabolism; D004232:Diuretics / Q000494:pharmacology; D004734:Energy Metabolism / Q000187:drug effects; D004976:Ethacrynic Acid / Q000494:pharmacology; D005665:Furosemide / Q000494:pharmacology; D005947:Glucose / Q000172:deficiency*; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D000860:Hypoxia / Q000473:pathology*; D066298:In Vitro Techniques; D008297:Male; D009474:Neurons / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D049994:Sodium Potassium Chloride Symporter Inhibitors; D064466:Solute Carrier Family 12, Member 1; D064506:Solute Carrier Family 12, Member 2
D002352:Carrier Proteins; D002712:Chlorides; D004232:Diuretics; C578716:Slc12a1 protein, rat; C578879:Slc12a2 protein, rat; D049994:Sodium Potassium Chloride Symporter Inhibitors; D064466:Solute Carrier Family 12, Member 1; D064506:Solute Carrier Family 12, Member 2; D002034:Bumetanide; D005665:Furosemide; D000255:Adenosine Triphosphate; D045304:Cytochromes c; D005947:Glucose; D004976:Ethacrynic Acid