Viable, physiologically intact ventricular slices from neonatal murine hearts provide a robust model to study loaded contractions, with preserved beta-adrenergic regulation and calcium handling.
Neonatal murine ventricular slices provide a robust, physiologically intact model for studying loaded contractions and pharmacological responses.
BACKGROUND/AIMS: Cardiac function is increasingly studied using murine models. However, current multicellular preparations to investigate contractile properties have substantial technical and biological limitations and are especially difficult to apply to the developing murine heart. METHODS: Newborn murine hearts were cut with a vibratome into viable tissue slices. The structural and functional integrity of the tissue was shown by histology, ATP content and sharp electrode recordings. RESULTS: Within the first 48 hours after slicing structure remained intact without induction of apoptosis. ATP concentrations and action potential parameters were comparable to those of physiological tissue. Isometric force measurements demonstrated a physiological force-frequency relationship with a ;primary-phase' negative force-frequency relationship up to 1-2 Hz and a ;secondary-phase' positive force-frequency relationship up to 8 Hz. (-)-Isoproterenol (10(-6) mol/l) increased active force to 251 +/- 35% (n=15) of baseline values and shortened relaxation times indicating a preserved beta-adrenergic regulation of contraction. Changes of the force-frequency relationship after application of ryanodine and nifedipine indicated functionality of calcium release from the sarcoplasmic reticulum and of L-type calcium channels. CONCLUSION: Generation of viable, physiological intact ventricular slices from neonatal hearts is feasible and provides a robust model to study loaded contractions.
Pillekamp et al. (Mon,) conducted a other in Cardiac function (preclinical model). Neonatal murine heart slices was evaluated on Structural and functional integrity (isometric force measurements, ATP, action potentials). Viable, physiologically intact ventricular slices from neonatal murine hearts provide a robust model to study loaded contractions, with preserved beta-adrenergic regulation and calcium handling.