Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

The electrophysiological properties of cultured human melanocytes were investigated using the whole-cell configuration of the patch-clamp technique. Depolarizations to membrane potentials more positive than -30 mV resulted in the rapid development ( < 1 ms to peak) of an inward current. The maximum peak current was observed at +10 mV and reached an average amplitude of about 270 pA. During the depolarizations, the current inactivated with a time constant of about 2 ms. The current was abolished by the addition of 0.3 microM tetrodotoxin, a blocker of voltage-gated Na(+)-channels, and disappeared when Na+ was omitted from the extracellular medium. In addition, the melanocytes contain at least two types of outward K(+)-current. The first type, observed in every cell, was highly sensitive (Ki 1 mM) to the K(+)-channel blocker TEA, required depolarizations beyond zero to be activated and did not inactivate. The second type was less regularly observed (10% of the cells). This current activated at more negative voltages (-20 mV), was resistant to TEA (20 mM) but was blocked by 2 mM 4-aminopyridine and inactivated rapidly during depolarizations. We conclude that human melanocytes are equipped with voltage-dependent Na(+)-channels, a delayed rectifying K(+)-current and a K(+)-current similar to the A-current in neurones.


Conference paper

Publication Date





333 - 338


4-Aminopyridine, Electric Conductivity, Humans, Male, Melanocytes, Membrane Potentials, Patch-Clamp Techniques, Potassium Channels, Sodium, Sodium Channels, Tetraethylammonium, Tetraethylammonium Compounds, Tetrodotoxin