Calcium channel blocking agents and potassium-stimulated release of glutamate from cerebellar slices.

The effects of calcium channel blockers and tetrodotoxin on the potassium-stimulated release of endogenous glutamate from rat cerebellar slices was assessed. Verapamil (10 microM), omega-conotoxin (1 and 10 microM) and cobalt (2 mM) all significantly decreased release. Amiloride (100 microM) and tetrodotoxin (0.5 and 1 microM) had no effect. The results suggest a role for N-type voltage-operated calcium channels in the potassium-stimulated release of glutamate.