Screening of the venoms of two Parabuthus scorpion species on isolated cardiomyocytes.

Crude, diluted venoms of Parabuthus transvaalicus and P. granulatus were tested on isolated cardiomyocytes. Ventricular myocytes were subjected to hypercontractility tests and whole-cell voltage clamp. Both venoms had a profound influence on the hypercontractility of cardiomyocytes, which was markedly decreased when they were pre-absorbed with commercial antiserum. Whole-cell clamp results showed an increase in the sodium current, and a retardation of the time course of inactivation, implicating the presence of an alpha toxin in both venoms.