How to obtain physiologically relevant cardiovascular data with students using chick embryo ventricular cardiomyocytes.

Abstract

The chick embryo ventricular cardiomyocyte model provides students easy access to experiments involving fundamental features of cardiac cell physiology and pharmacology. With standard physiology teaching laboratories and basic cell culture equipment, spontaneously beating colonies of electrically connected cardiomyocytes can be obtained by the students themselves. Students learn aseptic techniques and cell culture alongside experiments illustrating, at the simplest level of experimentation, how beating rate can be altered physiologically or pharmacologically. In the typical course of the type of experiments presented here, students first observe the effect of temperature (beating rates decline to a third going from 37°C to room temperature; e.g., to 40 from 130 beats/min) and media change (beating rates increase up to 50%) before moving on to the pharmacological characterization of various receptors in these cells. Most obviously, in the cardiac cell context, this involves drugs acting on β-adrenoceptor subtypes. Students can obtain predictable dose-dependent increases in beating rates (up to maximal 100% increases in beating rate; from ∼100 to 200 beats/min typically) with the addition of stimulatory β-adrenoceptor agonists (e.g., isoproterenol) but also observe dose-dependent decreases in beating rate with β₃-adrenoceptor agonists (reducing beating rate by up to a third). Consequently, "classical" log dose-response curves can be obtained in the "real world," enhancing student understanding of fundamental mechanisms of drug action. Although these experiments focus on physiological and pharmacological techniques, the model can be extended to encompass biochemical or molecular biological studies in terms of intracellular signaling systems activated and protein expression patterns.NEW & NOTEWORTHY Many in today's societies see the use of animals for experimentation and education as unnecessary and even immoral. There is nevertheless a need to investigate the fundamental physiological principles underlying life itself, and students need to be trained in these principles for the wider benefit of humanity and the planet. This article provides an ethical alternative to the traditional models used in the study of cardiac physiology to train the next generation of physiologists.