Leakkanaler

Leakkanaler, known in English as leak channels, are ion channels that conduct ions continuously at rest, remaining open independent of the strong voltage or ligand gating that characterizes many other channels. They create a steady leak conductance for specific ions, most commonly potassium, and to a lesser extent sodium, helping to establish and stabilize the resting membrane potential of cells such as neurons and muscle cells.

One major group comprises the two-pore-domain potassium channels (K2P), often referred to as potassium leak channels. These channels contribute to the resting conductance and can be modulated by physiological factors including pH, temperature, mechanical stretch, and various signaling molecules. Other notable leak channels include the sodium leak channel NALCN, which provides a baseline Na+ conductance that influences neuronal excitability.

Functionally, leak channels influence neuronal excitability by setting the resting potential and shaping the response to synaptic input. In epithelia and muscle, they help determine membrane potential and transepithelial ion movement. They are distinct from voltage-gated and ligand-gated channels in that they are not primarily opened or closed by changes in membrane potential or ligand binding, though many are sensitive to intracellular and extracellular conditions.

Clinical and research interest in leak channels includes their roles in pain, anesthesia, migraine, and epilepsy, as well as potential targets for drugs that modify neuronal excitability. Mutations or dysregulation of leak channels can alter excitability and have been linked to disease states. Leakkanaler are thus a fundamental component of the cellular ion conductance landscape across diverse tissues.