相关实验视频

Updated: Aug 18, 2026

Contractility Measurements on Isolated Papillary Muscles for the Investigation of Cardiac Inotropy in Mice
06:22

Contractility Measurements on Isolated Papillary Muscles for the Investigation of Cardiac Inotropy in Mice

Published on: September 17, 2015

新型内类药物对收缩蛋白的Ca++敏感性的影响

J C Rüegg

    Circulation
    |March 1, 1986
    PubMed
    概括

    新的心力强药物sulmazole和pimobendane通过增加肌纤维对的敏感性来增强心肌收缩. 这种对的敏感作用有助于它们在心脏肌肉中的积极内作用.

    更多相关视频

    Assessment of Myofilament Ca2+ Sensitivity Underlying Cardiac Excitation-contraction Coupling08:29

    Assessment of Myofilament Ca2+ Sensitivity Underlying Cardiac Excitation-contraction Coupling

    Published on: August 1, 2016

    Contractions of Human-iPSC-derived Cardiomyocyte Syncytia Measured with a Ca-sensitive Fluorescent Dye in Temperature-controlled 384-well Plates07:42

    Contractions of Human-iPSC-derived Cardiomyocyte Syncytia Measured with a Ca-sensitive Fluorescent Dye in Temperature-controlled 384-well Plates

    Published on: October 18, 2018

    相关概念视频

    Relaxation of Skeletal Muscles01:29

    Relaxation of Skeletal Muscles

    The period of muscle contraction primarily influences the duration of stimulation at the neuromuscular junction (NMJ), the presence of free calcium ions in the sarcoplasm, and the availability of energy or ATP to support contractions.
    When an action potential reaches the axon terminal, it depolarizes the membrane and opens voltage-gated sodium channels. Sodium ions enter the cell, further depolarizing the presynaptic membrane. This depolarization causes voltage-gated calcium channels to open.
    Smooth Muscle Contraction01:25

    Smooth Muscle Contraction

    Smooth muscle contraction is a complex process vital for various bodily functions, from maintaining blood vessel tension to facilitating the movement of food through the digestive tract. Unlike striated muscles, smooth muscle contraction begins more slowly and lasts longer.
    The onset of contraction is triggered by an increase in calcium ions within the sarcoplasm, similar to the process in striated muscle. However, smooth muscles have a relatively smaller reservoir of the sarcoplasmic...
    Antiarrhythmic Drugs: Class I Agents as Sodium Channel Blockers01:22

    Antiarrhythmic Drugs: Class I Agents as Sodium Channel Blockers

    Class I antiarrhythmic drugs are used to treat various types of arrhythmias or irregular heart rhythms. These drugs block the sodium (Na+) channels in the cardiac cells, thereby affecting the movement of electrical impulses across the heart. Class I antiarrhythmic drugs are divided into three subgroups: Class IA, Class IB, and Class IC, each with distinct mechanisms of action and effects on the heart.
    Class 1A Antiarrhythmic Drugs: These drugs work by moderately blocking sodium channels,...
    Antiarrhythmic Drugs: Class II Agents as β-Adrenergic Blockers01:24

    Antiarrhythmic Drugs: Class II Agents as β-Adrenergic Blockers

    Adrenergic stimulation generally impacts cardiac rate and rhythm. Specifically, stimulation of the β-adrenoceptors triggers an increase in intracellular calcium ion influx and pacemaker currents, which may cause arrhythmias. Catecholamines like adrenaline also demonstrate β2-adrenoceptor-mediated hypokalemia, impacting cardiac action potential and disrupting the normal cardiac rhythm. Class II antiarrhythmic drugs are β-adrenoceptor antagonists or β-blockers, which indirectly block calcium...
    Antiarrhythmic Drugs: Class III Agents as Potassium Channel Blockers01:12

    Antiarrhythmic Drugs: Class III Agents as Potassium Channel Blockers

    Class III antiarrhythmic drugs are a group of medications that can prolong action potentials in the heart. They achieve this by blocking potassium channels or enhancing inward currents from sodium channels. However, these drugs have a unique property of "reverse use-dependence," which is most pronounced at slower heart rates and can lead to torsades de pointes—a specific type of arrhythmia. However, it is essential to note that excessive QT interval prolongation—a measure of the heart's...
    Heart Failure Drugs: Inotropic Agents01:26

    Heart Failure Drugs: Inotropic Agents

    Positive inotropic agents are commonly used as the first line of treatment for heart failure. One such agent is digoxin, derived from the genus Digitalis, which has been known for centuries but effectively utilized since 1785. However, these cardiac glycosides can have potentially toxic effects due to their mechanism of action, which involves inhibiting Na+/K+-ATPase and increasing contractility. Digoxin is absorbed orally and distributed in various tissues, including the CNS. It has a long...