Fig. 4.

ILE rescues cardiomyocyte Ca²⁺ transients and contractility in the presence of verapamil. a Representative example of intracellular Ca²⁺ transients (top trace) and cell shortening (bottom trace) recorded from Fluo-4 AM-loaded ventricular myocytes field-stimulated at 2-Hz frequency. Application of verapamil (10 μM) causes substantial inhibition of both cell shortening and Ca²⁺ transient amplitude. Addition of ILE (0.5 vol%) results in rapid and almost complete recovery of both parameters. b, c Bar graphs report average data of Ca²⁺ transient amplitude and cell shortening, respectively, before and after application of verapamil and verapamil + ILE. All values were normalized to baseline values (control) before drug or ILE application. For Ca²⁺ transients, n = 17, for cell shortening, n = 10, 3–6 myocytes per animal. *P < 0.05, **P < 0.005 by paired two-tailed Student’s t test