Abstract:
The skin of the red-banded rubber frog is said to secrete an unidentified toxin. Whole skin extract
as well as HPLC fractions were tested for toxicity on viable, isolated cardiomyocytes. The skin extract
and one of its fractions were shown to be cardiotoxic. Whole-cell clamping tests demonstrated that both
extract and fraction interfered with the function of the potassium channels of the cardiomyocytes and
that the toxic substance has an affinity for the IK₁ channels. Investigations are in progress to isolate and
characterize the toxic substance.
