Action potential in muscles

Cheung and Daniel (1980) Maximal ratejof rise of action potential in muscle 32... 

The histrionicotoxins show only weak interactions with voltage-dependent sodium channels 245). Histrionicotoxins do reduce the rate of rise of action potentials in muscle. The profile of activity for seven histrionicotoxins in this regard is as follows isotetrahydrohistrionicotoxin > tetrahydrohistrionicotoxin > perhydrohistrionicotoxin > isodihydro-histrionicotoxin > neodihydrohistrionicotoxin > octahydrohistrionico-toxin > histrionicotoxin. Thus histrionicotoxin appeared the least potent alkaloid of this class with respect to classical local anesthetic activity. In frog sciatic nerve, histrionicotoxin at 500 pM causes only a slight blockade of action potentials (774). 

---