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Updated: Aug 9, 2026

Measurement of Calcium Fluctuations Within the Sarcoplasmic Reticulum of Cultured Smooth Muscle Cells Using FRET-based Confocal Imaging
10:05

Measurement of Calcium Fluctuations Within the Sarcoplasmic Reticulum of Cultured Smooth Muscle Cells Using FRET-based Confocal Imaging

Published on: June 20, 2016

Effect of halothane on cardiac sarcoplasmic reticulum Ca2+-ATPase at low calcium concentrations

S M Malinconico, R L McCarl

    Molecular Pharmacology
    |July 1, 1982
    PubMed

    Insights

    Halothane significantly depresses cardiac sarcoplasmic reticulum Ca2+-ATPase activity, especially at low calcium levels. Increasing external calcium antagonizes this halothane effect, impacting myocardial function.

    Area of Science:

    • Biochemistry
    • Cardiovascular Physiology

    Background:

    • Cardiac sarcoplasmic reticulum Ca2+-ATPase is crucial for muscle relaxation.
    • Halothane is an anesthetic agent known to affect cardiac function.

    Purpose of the Study:

    • To investigate the effect of halothane on cardiac sarcoplasmic reticulum Ca2+-ATPase activity at low calcium concentrations.
    • To elucidate the mechanism of halothane's interaction with Ca2+-ATPase.

    Main Methods:

    • Studied isolated cardiac sarcoplasmic reticulum vesicles.
    • Assessed Ca2+-ATPase activity at varying calcium concentrations (0.4-20 microM) in the presence of clinical halothane concentrations (1%-3%).
    • Analyzed enzyme kinetics (Vmax and Km).

    Main Results:

    • Halothane significantly depressed Ca2+-ATPase activity, particularly at lower calcium concentrations.
    • Increased external calcium antagonized the halothane-induced depression.
    • Halothane acted as a competitive inhibitor, increasing Km without altering Vmax.

    Conclusions:

    • Halothane's inhibition of cardiac sarcoplasmic reticulum Ca2+-ATPase at low calcium contributes to myocardial depression.
    • Understanding this mechanism is vital for anesthetic safety and cardiac care.

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