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Drugs acting on circulation system and blood / blood- forming organs
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Cardiovascular System
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Overview of Cardiovascular System §Common Cardiac Diseases §Abnormal contractility : Heart failures §Abnormal rhythms : Arrhythmias §Abnormal blood supply : Ischemic heart diseases §Myocardial disorders §Common vascular diseases §Abnormal systematic resistance : Hypertension §Dysfunction of coronary vessles : Coronary vascular diseases §Dysfunction of cerebral vessles : Cerebral ischemia, hemorrhage §Dysfunction of pulmonary vessles : Pulmonary hypertension §Dysfunction of peripheral vessles: P eripheral vascular disorder §Arteriosclerosis
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Overview of Cardiovascular Drugs §Classification based on target organs §Heart : Heart failures, arrhythmias, cardiac ischemia, over-load of the heart §Vessels : Vasodilatation, vasoconstriction, arteriosclerosis §Classification based on the mechanisms §Ion channels : Ca 2+, Na +, K + channels §Receptors : Adrenoceptors, AT receptors, etc. §Enzymes : ACEI 、 Na + -K + -ATPase 、 HMG-CoA reductase §Others : Diuretics
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Drugs affecting ion channels in CVS
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A. General properties of ion channels in CVS §Properties of ion channels §Permeation §Selectivity §Gating voltage-gated § chemically gated: ligand-gated § cyclic nucleotide -gated § mechanosensitive § nongated background / leak channels
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Ion transmembrane transport
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Gating mechanisms of ion channels
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A. General properties of ion channels in CVS §Voltage-gated ion channels §Na + channels §Ca 2+ channels §K + channels
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Structure of α-subunit Voltagesensor
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Na + Channels K + Channels Ca 2+ Channels
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General structures of ion channels
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A. General properties of ion channels in CVS §Functional regulation of voltage-gated ion channels § Activation (open) § Inactivation (close)
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Gating modes of ion channels
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A. General properties of ion channels in CVS §Ligand-gated ion channels
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B. Drugs affecting ion channels in CVS Calcium channel blockers §1. Intracellular free Ca 2+ §(1) Ca 2+ inward flow Voltage-gated : L, T, N, P, Q, R types § Voltage-gated : L, T, N, P, Q, R types Chemically gated: NMDA receptor § Chemically gated: NMDA receptor §(2) Release of stored Ca 2+ IP 3 receptor § IP 3 receptor
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§Box Voltage-gated calcium channels §L-type calcium channels §Activated at - 10 mV, inactivated at - 60 ~- 90 mV; §Long lasting opening; §Distributed in myocardial and vascular tissues §T-type calcium channels §Activated at - 70 mV, inactivated at - 100 ~- 60 mV; §Transient opening; §Distributed mainly in heart conduction system (S-A node), arterial walls, etc.
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§2. Structures and functions of voltage-gated calcium channels 5 subunits § 5 subunits § 1 subunit is a more important structure § 4 domains, 6TM in each domain § S4: voltage sensor, , S6: site of drug binding B. Calcium channel blockers
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§3. Classification of calcium channel blockers §Selective calcium channel blockers §Dihydropyridines ( 二氢吡啶类 ): nifedipine 硝苯地平 nimoldipine 尼莫地平 nimoldipine 尼莫地平 amlodipine 氨氯地平 Phenylalkylamines ( 苯烷胺类 ): verapamil 维拉帕米 amlodipine 氨氯地平 Phenylalkylamines ( 苯烷胺类 ): verapamil 维拉帕米 §Benzothiazepines ( 苯硫卓类 ): diltiazem 地尔硫卓 §Non-selective calcium channel blockers B. Calcium channel blockers
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Verapamil维拉帕米 Nifedipine硝苯地平Diltiazem地尔硫卓
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§4. Pharmacological effects §(1) Cardiac effects §A. Negative inotropic effect : excitation- contraction discoupling §B. Negative chronotropic and slowing conduction action: phase 4 of spontaneous depolarization and phase 0 of depolarization of slow response autonomic cells §C. Protective effect on cardiac ischemia B. Calcium channel blockers
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§(2) Effects on smooth muscles A. Vascular smooth muscle: relaxing the arterial smooth muscles, especially coronary artery §B. Others : smooth muscle of bronchus, gastrointestinal tract, ureter, uterus B. Calcium channel blockers
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§(3) Anti-atherosclerosis § Alleviating Ca 2+ overload § Inhibit proliferation of smooth muscle cells and protein production of arterial matrix § Inhibit lipid peroxidation § Decrease cholesterol level §(4) Hemodynamic effects Improving membrane stability of erythrocytes § Improving membrane stability of erythrocytes Inhibiting platelet aggregation § Inhibiting platelet aggregation B. Calcium channel blockers
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§(5) Others Kidney: Increase the blood flow of kidney § Kidney: Increase the blood flow of kidney § Endocrine: inhibiting the release of ACTH, TSH, insulin, etc. B. Calcium channel blockers
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§5. Action modes §(1) actions on different functional states § § Activated ( 0 phase ) : verapamil § Inactivated ( 1~3 phases ) : diltiazem § Resting ( 4 phase ) : nifedipine B. Calcium channel blockers
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verapamil diltiazem nifedipine Resting (closed) Activated (open) Inactivated (closed)
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verapamil diltiazem nifedipine
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§(2) Open frequency-dependency §Verapamil, diltiazem: frequency-dependent §Nifedipine: frequency-independent B. Calcium channel blockers
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§6. Clinical uses §(1) Angina pectoris §Variant angina: §Variant angina: nifedipine §Stable angina: §Stable angina: verapamil, diltiazem §Unstable angina: §Unstable angina: verapamil, diltiazem, § nifedipine + receptor blockers B. Calcium channel blockers
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(2) Arrhythmias supraventricular tachycardia arrhythmias induced by triggered activity following after-depolarization arrhythmias induced by triggered activity following after-depolarization - verapamil, diltiazem - verapamil, diltiazem B. Calcium channel blockers
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(3) Hypertension §Severe: nifedipine §Mild to moderate: verapamil, diltiazem §Complicated with coronary heart disease, myocardial ischemia, peripheral vascular diseases, bronchial asthma, chronic obstructive pulmonary diseases, etc. B. Calcium channel blockers
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§(4) Cerebrovascular diseases transient ischemic attack, cerebral thrombosis cerebral thrombosis subarachnoid hemorrhage subarachnoid hemorrhage (5) Others peripheral vascular spasmodic disease arteriosclerosis arteriosclerosis etc. etc. B. Calcium channel blockers
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§7. Adverse effects peripheral edema: nifedipine > verapamil > diltiazem symptoms of sympathetic excitation (heart rate increase): nifedipine symptoms of sympathetic excitation (heart rate increase): nifedipine heart rate reduced: verapamil, diltiazem heart rate reduced: verapamil, diltiazem hypotension: nifedipine hypotension: nifedipine §Contraindications : hypotension (nifedipine); severe heart failure, sinus bradycardia, atrioventricular block (verapamil, diltiazem) B. Calcium channel blockers
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§8. Special agents Nifedipine 硝苯地平 B. Calcium channel blockers
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§(1) Pharmacological effects §Vessels: vasodilatation, hypotension, increase of cardiac output §Heart: reflex increase of heart rate, weak direct inhibiting effects §(2) Clinical uses §Angina pectoris ; hypertension ; peripheral vascular diseases; etc. §Slow releasing forms: adverse effects ; action duration §(3) Adverse effects §Hypotension; tachycardia; edema; headache, flushing, etc. B. Calcium channel blockers
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Nimodipine 尼莫地平 Selectively acting on cerebral vasculature B. Calcium channel blockers
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Verapamil 维拉帕米 Potent efficacy on the heart, and weak on the vessels B. Calcium channel blockers
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Diltiazem 地尔硫卓 Potent efficacy on the heart and the vessels B. Calcium channel blockers
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B. Drugs affecting ion channels in CVS Potassium channel modulators Potassium channel blockers Sulfonylureas: for treatment of diabetes Drugs under research Potassium channel openners Effects are similar to calcium channel blockers
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