[Estimation of free calcium level within synaptosomes by using fura-2 and the effect of calcium channel agonist and antagonist].
The cytosolic free calcium concentration [Ca2+]i in synaptosomes was determined with the fluorescent indicator fura-2, the effects of calcium channel agonist and antagonist on intracellular Ca2+ level were studied. The cytosolic ionized calcium concentrations in resting status were between 200 nmol/L and 400 nmol/L. Cytosolic Ca2+ was elevated following increases in Ca2+ concentration in the medium, plasma membrane depolarizations induced by KCl, and the addition of glutamate and NMDA. On the other hand, the increase of cytosolic Ca2+ induced by KCl was decreased by verapamil and that induced by NMDA was decreased by MgCl2. A few critical problems in [Ca2+]i detection were also discussed.
Gao
H
H
Institute of Materia Medica, Chinese Academy of Medical Sciences, Beijing.
Feng
Y P
YP
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002120:Calcium Channel Agonists / Q000494:pharmacology*; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D016257:Fura-2; D015636:Magnesium Chloride / Q000494:pharmacology; D008297:Male; D016202:N-Methylaspartate / Q000494:pharmacology*; D011189:Potassium Chloride / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D013574:Synaptosomes / Q000378:metabolism*; D014700:Verapamil / Q000494:pharmacology
D002120:Calcium Channel Agonists; D002121:Calcium Channel Blockers; D015636:Magnesium Chloride; D016202:N-Methylaspartate; D011189:Potassium Chloride; D014700:Verapamil; D002118:Calcium; D016257:Fura-2