Ca2+ depletion facilitates taurine release in cultured rat astrocytes.
Removal of external Ca2+ facilitated endogenous taurine release in cultured rat astrocytes. The stimulated release was not affected by furosemide, sucrose, tetrodotoxin and 3,4-dichlorobenzamil, but partially inhibited by nifedipine. Omission of external Na+ increased basal taurine release, and the effects of Na+ removal and Ca2+ depletion on the release were additive. The Na(+)-free condition did not affect Ca2+ paradox-induced cell death in astrocytes. These findings suggest that Ca2+ depletion facilitates taurine release in a mechanism independent of volume and the Na+ gradient and that the release is not involved in Ca2+ paradox-induced delayed cell toxicity in astrocytes.
Department of Pharmacology, Faculty of Pharmaceutical Sciences, Osaka University, Japan.
K
K
Takuma
T
T
Matsuda
Y
Y
Kishida
S
S
Asano
J
J
Azuma
A
A
Baba
D000584:Amiloride / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D000831:Animals, Newborn; D001253:Astrocytes / Q000187:drug effects* / Q000378:metabolism; D002118:Calcium / Q000494:pharmacology*; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D002352:Carrier Proteins / Q000378:metabolism; D002478:Cells, Cultured / Q000187:drug effects; D003470:Culture Media / Q000737:chemistry; D009543:Nifedipine / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012964:Sodium / Q000378:metabolism; D013654:Taurine / Q000037:antagonists & inhibitors / Q000378:metabolism*
D002121:Calcium Channel Blockers; D002352:Carrier Proteins; D003470:Culture Media; C041470:3',4'-dichlorobenzamil; D013654:Taurine; D000584:Amiloride; D012964:Sodium; D009543:Nifedipine; D002118:Calcium