PCL302H1 Lecture Notes - Lecture 19: Channelopathy, Cyclic Adenosine Monophosphate, Resveratrol
Document Summary
Puffer fish- tetrodotoxin (ttx)- spontaneous ap is inhibited, vg ca2+ is resistant. Cone snails- w-conotoxin (gvia, mvia, cvid) and. Effect of enhanced activation: beta scorpion 60-65 aa portion causes enhanced activation and stays open longer, therefore inactivation is affected. Channel opens at -30 mv if enhanced, it will open at -40 mv resulting in a leftward shift in activation-> increased channel sensitivity induces convulsion or seizures. Site 1: pore blockage by ttx is not considered competitive blocking. Inhibitors of vg channels (von williams classification- not all) Resveratrol (found in red wine, grape extract) hydrophobic. Lidocaine, procaine (local anesthetic, inhibits ap firing, higher affinity to inactive state>open>rest), hydrophllic and works on high frequency. Upward is due to opening of sodium channels 1-closing of potassium channels and triggers opening calcium channels that extend this plateau of the ap of cardiac cell and then we see the opening of potassium channels 3-4.