CaV And Hypertensio Flashcards
Types of CaV channels
• L-type (CaV1) -> 1.1, 1.2, 1.3, 1.4
• P/Q-type (CaV2.2)
• N-type (CaV2.1)
• R-type (CaV2.3)
• T-type (CaV3)
• L-type consists of 4 genes encoding
different α1 subunits
What is Ca2+ important for
Cardiac and smooth muscle contraction
L-type Ca channels
(CaV1.2 and CaV1.3)
Found in the heart ad in vascular smooth muscle
Drugs acting on these can be used to control heart rate and vascular tone (dampe done the CaV)
They are Ca channel blockers - antagonists
Pharmacology of CaV Chanel’s
• Phenylalkylamines – verapamil - preferential for heart
• Dihydropyridines – nifedipine - preferential for hypertension
• Benzothiazepines - diltiazem
These drugs can cause AV block and cardiac slowing
These drugs can induce arteriolar dilatation and reduce blood pressure – act as vasodilators
Side effects – flushing, headaches, ankle swelling, cardiac rhythm, constipation
Linked to blocking CaV channels in other locations
CCB
Ca channel blockers
Bind to a1 subunit
interfere with voltage-dependent cycling between
resting –> open–> inactivated states
Higher affinity binding occurs to the open state or inactivated state
IIIS5, IIIS6 and IVS6 segments are major areas of drug binding