Model of preconditioning in guinea pig and rabbit isolated hearts loaded with voltage-sensitive dye Di-4-ANEPPS

Cardiovascular system diseases are frequent cause of morbidity and mortality in Western countries. In our laboratory, early stages of ischemia - prominent diagnosis in this group - are examined by recording electrograms and action potentials by optical probe in isolated mammalian hearts loaded with voltage-sensitive dye (VSD) di-4-ANEPPS. In this study, guinea pig and rabbit isolated hearts were exposed to special protocol of s.-c. preconditioning - attenuation of the symptoms during repeated exposure to ischemic insult. In guinea pig myocardium, additive effect of VSD and ischemia triggered more serious and more frequent arrhythmias then the same situation in rabbit hearts. Moreover, expected attenuation of these effects was not observed, on the contrary to rabbit myocardium, where typical preconditioning was present. Rabbit myocardium appears to be more suitable for studies in such experimental design.