Paxilline. Paxilline is a selective blocker of Kca1.1 (high-conductance Ca2+ -activated K+,BK) channels. It belongs to a set of tremorgenic indole alkaloids which are lipid soluble and also include Pentrium A (#P-650) and Verruculogen (#V-500). Paxilline enhanced the electrically induced twitch contractions in guinea pig ileum, without influencing the contractions provoked by exogenous acetylcholine. Paxilline was shown to inhibit the peptidyle toxin resistant combination alpha+beta4 channels (for more background see) expressed in CHO cells. It was shown to be as potent as Iberiotoxin (#STI-400) in action potential broadening in hippocampus and amygdala. Cell Ca2+ Signaling; Intracellular Ca2+ Mobilizers. Ion Channel Modulators; K+ Channel Blockers.