Comparison of the tissue response during the loading with voltage-sensitive dye in two animal models

conference paper

English

Voltage-sensitive dyes (VSD's) can be used in touch-less recording of action potentials from animal hearts. VSD's undergo changes in their electronic structure, and consequently their fluorescence spectra, in response to changes in the surrounding electric field. This optical response is sufficiently fast to detect transient potential changes in excitable cardiac cells. Two animal models are employed in our laboratory to record monophasic action potentials using VSD in isolated hearts perfused according to Langendorf - guinea pig and rabbit. The hearts of both species undergo the same isolation and loading procedures. Briefly, the spontaneously beating heart is mounted on Langendorf set and perfused with constant perfusion pressure with Krebs-Henseleit solution (37 C, 1,25mM Ca2+). After control period (20min), the heart is loaded with di-4-ANEPPS (2uM) diluted in perfusion solution (25 min) and then washed-out with dye-free perfusion solution (25 min). It has been observed that during the loading procedure prominent electrophysiological changes occur, accompanied with changes in mean coronary flow in the isolated heart. In our study, 15 guinea pig (both sexes, 360+/-80g) and 10 rabbit hearts (both sexes, 3,1+/-0.4kg) were included. Mean coronary flow (in ml/min) and ECG (touch-less method) were followed during control, loading and washout periods. In guinea pig hearts, mean coronary flow does not change during the loading, however decreases significantly during wash-out period. In rabbit hearts, these changes of coronary flow have not been found. In ECG, during loading marked decrease in the spontaneous heart rate is present in guinea pig hearts, which is not observed in rabbit hearts. The frequency is only partially restored during wash-out period. Changes in the shape of T wave together with atrio-ventricular dissociation are other prominent findings in guinea pig model. These changes are only slightly indicated in rabbit hearts. Thus, it may be concluded that rabbit heart is more resistant to the changes which are triggered with VSD application. Although these changes are partially reversible in guinea pig heart, this model seems to be more sensitive and thus less reliable, especially when concerning studies of conductive system.

tissue, voltage-sensitive dye, animal model

Novakova M., Blaha M., Bardonova J., Provaznik I.

2005

1. 9. 2005

IEEE

Francie

0-7803-9337-6

Computers in Cardiology

535

538

4