Dimethyl sulfoxide depresses skeletal muscle contractility

Area of Science:

• Physiology
• Pharmacology

Background:

• Dimethyl sulfoxide (DMSO) is widely used in skeletal muscle research as an antioxidant or drug solvent.
• Its direct impact on muscle contractile function requires clarification.

Purpose of the Study:

• To investigate the direct effects of DMSO on rat diaphragm muscle contractile properties.
• To determine the dose-dependence and reversibility of these effects.

Main Methods:

• Diaphragm fiber bundles from rats were isolated and studied in vitro.
• Contractile forces during twitch and tetanic stimulations were measured at various DMSO concentrations (0.6-640 mM).
• Reversibility was assessed by washout.

Main Results:

• DMSO decreased force production in twitch and submaximal tetanic contractions (30- and 60-Hz).
• A dose-dependent depression of the force-frequency relationship was observed.
• No significant effect on maximal tetanic force (200 Hz) was detected.
• DMSO-induced depression was reversible upon washout.

Conclusions:

• DMSO reversibly depresses diaphragm contractile function in a dose-dependent manner.
• The primary mechanism appears to be the inhibition of excitation-contraction coupling.
• These findings are crucial for interpreting studies using DMSO in skeletal muscle research.