It is unknown, however, whether the combination of a Ca2+ channel blocker with dantrolene will also benefit diabetic patients because, in addition to increasing oxidative stress and inducing endothelial dysfunction, diabetes alters SR Ca2+ content, SR protein expression, RyR2 mRNA and RyR2 protein levels in a rat heart [18], and L-type Ca2+ channel regulation and expression in VSM [4]. The gene discussed is RYR2; the disease is endothelial dysfunction.