Examination of the Impact of Aging and the Sympathomimetic Isoprenaline on Myocardial Function Using the Langendorff Heart Model

Abstract

 Introduction: The Langendorff model of the isolated heart is an experimental model that is widely used in cardiovascular research in the fields of physiology, pharmacology, and toxicology. It is based on ex vivo perfusion of the heart isolated from an experimental animal, whereby а system of transducers and amplifiers enables the measurement of hemodynamic parameters and the assessment of the effects of the previously administered pharmacologically active substance on the myocardium.

 Aim: The aim of this study was to determine the differences in the cardiovascular response caused by aging, as well as by treating experimental rats with the β-agonist isoprenaline. 

Materials and Methods: Male Wistar albino rats were divided into a test group (3 older rats) and a control group (6 young rats) in order to measure the values of hemodynamic parameters (rate of change in systolic pressure (dP/dt max), rate of change in diastolic pressure (dP/dt min), left ventricular systolic pressure (SLVP), left ventricular diastolic pressure (DLVP), heart rate (HR), and coronary flow (CF)) at increasing perfusion pressures. In the second part of the test, the same parameters were measured under the same conditions in the test group, which consisted of 3 rats previously treated with isoprenaline according to a certain scheme, and in the control group, with 3 untreated rats. 

Results: Statistically significant differences in heart function were observed between young and old rats at all values of perfusion pressure. Differences were also observed in the heart function of rats administered isoprenaline and untreated rats, although they did not turn out to be statistically significant.

 Conclusion: Aging leads to significant changes in the function of the heart muscle. Isoprenaline has the potential to impair myocardial function, but further research is needed.