Latrunculin B

Latrunculin B, an antimicrobial marine alkaloid, is an actin polymerization inhibitor. Latrunculin B regulates pulmonary vein electrophysiological characteristics and attenuates stretch-induced arrhythmogenesis. Antifungal and antiprotozoal activity^[1][2]. In Vitro: Latrunculin B displays growth inhibition of HeLa cells with an IC₅₀ value of 1.4 μM^[1].
Latrunculin B modulates electrophysiological characteristics and arrhythmogenesis in pulmonary vein cardiomyocytes. Latrunculin B (100 nM) decreases the spontaneous electrical activity by 16±4% in pulmonary vein (PV) preparations. Latrunculin B (100 nM) decreases the late Na⁺ current, L-type Ca²⁺ current, Na⁺/Ca²⁺ exchanger current, and stretch-activated BKCa current in PV cardiomyocytes. Latrunculin B reduces the transient outward K⁺ current and ultra-rapid delayed rectifier K⁺ current, but increases the delayed rectifier K⁺ current in isolated PV cardiomyocytes. Latrunculin B (100 nM) decreases intracellular Ca²⁺ transient and sarcoplasmic reticulum Ca²⁺ content in PV cardiomyocytes. Latrunculin B attenuates stretch-induced increased spontaneous electrical activity and trigger activity^[2].