Ca CHANEL BLOCKERS
1 Importance
of calcium Chanel activation
in smooth muscle contraction
Ca2t Chanel antagonists
B
A
Benzothiazepines
Dihydropyridines nylalkyamines
Rate
limiting
Mechanism of action
Calcium antagonists block the entry of calcium
through
the calcium Chanel in vascular smooth muscle and
myocardium
Less Ca2T is available for contractile apparatus
Vasodilation
Negative inotropic effects
A Dihydropyridines Nifedipine
Am lodipine
Lercanidipine
, Blocks activation of
L
type Caat channels
Calcium calmodulin
cannot activate
myosin light chain
kinase
B c Benzothiazi pines Diltiazem
Phenylalky amines Verapamil
Blocks activation of
L
type Coit Channel
Calcium troponin
cannot activate actin
myosin myo filaments
NB Both intracellular calcium to relax either
smooth muscle vasodilation or cardiac muscle cell
1 Importance
of calcium Chanel activation
in smooth muscle contraction
Ca2t Chanel antagonists
B
A
Benzothiazepines
Dihydropyridines nylalkyamines
Rate
limiting
Mechanism of action
Calcium antagonists block the entry of calcium
through
the calcium Chanel in vascular smooth muscle and
myocardium
Less Ca2T is available for contractile apparatus
Vasodilation
Negative inotropic effects
A Dihydropyridines Nifedipine
Am lodipine
Lercanidipine
, Blocks activation of
L
type Caat channels
Calcium calmodulin
cannot activate
myosin light chain
kinase
B c Benzothiazi pines Diltiazem
Phenylalky amines Verapamil
Blocks activation of
L
type Coit Channel
Calcium troponin
cannot activate actin
myosin myo filaments
NB Both intracellular calcium to relax either
smooth muscle vasodilation or cardiac muscle cell
