Porphyrin derivatives as potent and selective blockers of neuronal Kv1 channels.

Selective inhibitors of voltage-activated K(+) channels are needed for the treatment of multiple sclerosis. In this work it was discovered that porphyrins bearing 2-4 carbon alkyl ammonium side chains predominantly blocked the Kv1.1 current whilst Kv1.2 was susceptible to a porphyrin bearing polyamine side chains.