Ion currents of cardiomyocytes in different regions of the Göttingen minipig heart

Introduction The Göttingen minipig is a promising model for pharmacological safety assessment and for translational research in cardiology. We have examined the main ion currents in cardiomyocytes of the minipig heart. Methods Cardiac cells were isolated from different cardiac regions (endo-, mid- and epicardial left ventricle and right ventricle) from Göttingen minipigs and examined using the whole cell patch clamp technique combined with pharmacological interventions. Results The inward rectifier (I_K1), the delayed rectifier (I_K), with the rapid and slow components, (I_Kr, I_Ks) and the L-type Ca^2 + channel (I_Ca,L) were identified in the different regions of the heart, whereas the Ca^2 +-independent transient outward current (I_to1) was observed in only a few cells. I_K1 was similar in the cardiac regions with a slightly lower value in the epicardial cells. I_Ks was smaller in epi- and endo-cardial regions. Discussion The equivalents of the main human cardiac ion currents are present in the minipig cardiomyocytes with the exception of the Ca^2 +-independent I_to1. The study provides further evidence that the minipig is a valid model for investigating cardiovascular pharmacology.