Trimethyltin Selectively Alters Activity of Ca(++), Mg(++), and (Ca(++) + Mg(++))-ATPases of Human Neuroblastoma

摘要

Neurotransmitter release from nerve terminals is coupled to the intracellularconcentration of Ca++. The regulation of internal Ca++ pools is, in turn, accomplished by several processes which include the transport of Ca++ into mitochondria, the binding of Ca++ by intraneuronal or membrane proteins, the exchange of intraneuronal Ca++ with extracellular Na+ via an antiport process, and finally, Ca++ extrusion or sequestration by Ca++-activated adenosine triphosphatases (ATPases). These processes are sensitive targets for a wide range of neurotoxic compounds with industrial, agricultural, and military applications. In fact, (Ca++ + Mg++)-ATPase and an associated ion channel are inhibited by Mojave toxin and activated by maitotoxin, two of the most potent known naturally occurring neurotoxins. (jes)