Azumolene (EU4093 free base), a Dantrolene analog, is a muscle relaxant. Azumolene is a ryanodine receptor (RyR) modulator and inhibits the calcium-release through ryanodine receptor. Azumolene can be used for malignant hyperthermia research[1][2].

Pretreatment with 20 µM Azumolene for 1-2 min inhibits SOCE activated by subsequent addition of caffeine and ryanodine to promote RyR-dependent sarcoplasmic reticulum Ca2+ store depletion in mouse myotubes and adult muscle fibers[2].

The effect of Azumolene (EU4093) on the twitch of the intact rat soleus preparation is nearly maximal at a dose of 20 mg/kg. This dose of Azumolene reduces the amplitude of the twitch to 31.9% of the control value. The contraction of intrafusal muscle as measured by the response of spindle afferent discharge is also reduced by Azumolene[1].

[1]. G C Leslie, et al. The effect of EU4093 (azumolene sodium) on the contraction of intrafusal muscle in the soleus muscle of the anaesthetized rat. Br J Pharmacol. 1989 Aug;97(4):1151-6. [2]. Viktor Yarotskyy, et al. Accelerated activation of SOCE current in myotubes from two mouse models of anesthetic- and heat-induced sudden death. PLoS One. 2013 Oct 15;8(10):e77633.