What is ‘inward rectification’?
Conductance of an ion channel:
- Electrical conductivity is a measure of the ability of a substance to conduct electrical current or to transport an electrical charge.
- Electrical conductivity is measured in siemens per meter (SI unit) or in picosiemens (pS). 1 pS = 10-12 siemens.
- Different channels have different electrical conductivity (Range: 1-2 pS to 100 pS; for different channels).
- Inward rectification: For a particular channel, its conductance varies depending on the direction that the ion is moving, whether moving into the cell or moving from inside to outside of cell. If a channel has greater conductance for the ion moving into the cell, as opposed to moving out of the cell, the channel is called ‘inward rectifier’ channel. E.g., inward rectifier K+ channel in heart.