The inhibition of Na-dependent Ca uptake by verapamil in synaptic plasma membrane vesicles.
This study on the effect of verapamil on the Na+-dependent Ca2+ uptake system (Na+-Ca2+ exchanger) of synaptic plasma membrane (SPM) vesicles showed that verapamil inhibited the Na+-dependent Ca2+ uptake in a dose dependent manner. A 50% inhibition was obtained with 175 microM verapamil. Calcium uptake in SPM vesicles is dependent on the Na+ gradient across the membrane and on the membrane potential. Both components of the Ca2+ uptake system were inhibited by verapamil. Na+-coupled GABA uptake in SPM vesicles was also inhibited by verapamil in a similar dose-dependent fashion. It seems therefore that verapamil inhibits Na+ gradient driven processes in synaptic plasma membrane vesicles.
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D066298:In Vitro Techniques; D008928:Mitochondria / Q000378:metabolism; D011188:Potassium / Q000494:pharmacology; D051381:Rats; D012964:Sodium / Q000502:physiology*; D013572:Synaptic Vesicles / Q000187:drug effects / Q000378:metabolism*; D013997:Time Factors; D014700:Verapamil / Q000494:pharmacology*; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
D005680:gamma-Aminobutyric Acid; D012964:Sodium; D014700:Verapamil; D011188:Potassium; D002118:Calcium