Ion Channel

Transmembrane proteins that form selective pores allowing specific ions (Na+, K+, Ca2+, Cl-) to flow across cell membranes down their electrochemical gradient. Ion channels regulate membrane potential, cell signaling, and muscle contraction. They can be gated by voltage, ligands, or mechanical stimuli.

Exemples

• Sodium channels blocked by lidocaine (local anesthesia)
• Calcium channels blocked by amlodipine (hypertension)
• Potassium channels opened by minoxidil (hair growth)