Effect of calcium on Na-K-ATPase activity in depolarized rat cortical synaptosomes as determined on the basis of oxygen consumption.
The oxygen consumption of rat cortical synaptosomes together with its ouabain-sensitive component were measured after veratrine-induced depolarization in the presence and in the absence of calcium, and with calcium added after depolarization by veratrine or potassium. Taking the ouabain-sensitive component of oxygen consumption as an indicator of Na-K-ATPase activity it was concluded that calcium entry during depolarization decreased synaptosomal Na-K-ATPase activity only slightly and in a protracted manner. Consequently, Ca++-induced inhibition of Na-K-ATPase does not seem to serve as a "trigger" mechanism of transmitter release.
Kálmán
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D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D002540:Cerebral Cortex / Q000201:enzymology*; D066298:In Vitro Techniques; D018377:Neurotransmitter Agents / Q000378:metabolism; D010042:Ouabain / Q000494:pharmacology; D010101:Oxygen Consumption; D051381:Rats; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*; D009435:Synaptic Transmission / Q000187:drug effects; D013574:Synaptosomes / Q000201:enzymology / Q000378:metabolism; D014702:Veratrine / Q000494:pharmacology
D018377:Neurotransmitter Agents; D010042:Ouabain; D000254:Sodium-Potassium-Exchanging ATPase; D014702:Veratrine; D002118:Calcium