title: Fluorescence-based system for measurement of electrophysiological changes in stretched cultured cardiomyocytes.
abstract: Acute or sustained stretch of cardiac tissue is known to play a key role in arrhythmogenesis. Using a fluorescence approach, we designed a system measuring calcium transients and transmembrane potential changes in monolayers of cultured cardiomyocytes under uniaxial elongation and electrical stimulation. Cardiac myocytes are seeded on a rectangular PDMS template held and stretched by a motorized linear guide system. Electrical stimulation is performed with two parallel carbon electrodes supplied by amplified pulses from a digital-to-analog converter. The cells are stained with either voltage- or calcium-sensitive dye (di-4-ANEPPS and Fluo-4 AM respectively). The two available excitation light sources are both current-controlled LED arrays (λ = 523 ± 45 nm for di-4-ANEPPS and λ = 505 ± 15 nm for Fluo-4 AM). The filtered emitted fluorescence (λ > 610 nm for di-4-ANEPPS and λ = 535 ± 25 nm for Fluo-4 AM) is transduced to current with a photodiode, converted to amplified voltage signals and digitized. The design and preliminary validation results are presented.
authors.affiliation: Montreal Heart institute, Montreal, Quebec, Canada.
authors.forename: James E
authors.initials: JE
authors.lastname: Duverger
authors.forename: Jonathan
authors.initials: J
authors.lastname: Béland
authors.forename: Ange
authors.initials: A
authors.lastname: Maguy
authors.forename: Mouhamed M
authors.initials: MM
authors.lastname: Adegbindin
authors.forename: Philippe
authors.initials: P
authors.lastname: Comtois
mesh_terms: D000818:Animals; D018929:Cell Culture Techniques / Q000295:instrumentation*; D002460:Cell Line; D055119:Elastic Modulus / Q000502:physiology; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006801:Humans; D040542:Mechanotransduction, Cellular / Q000502:physiology*; D036641:Microscopy, Fluorescence, Multiphoton / Q000295:instrumentation*; D032383:Myocytes, Cardiac / Q000502:physiology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity