Increased susceptibility of the left compared to the right ventricle to remote ischemia/reperfusion injury in human C1-inhibitor-overexpressing transgene mice

Acute myocardial injury has been demonstrated as a remote sequela of severe lower torso ischemia-reperfusion (I/R) due to proinflammatory events. In a model of I/R injury, administration of C1 esterase inhibitor (C1-Inh) reduces myocardial necrosis. We investigated the susceptibility of the left (LV) versus right ventricle (RV) and the protective effect of transgenic C1-Inh-overexpressing mice. Two groups of mice (n = 6) underwent a 2-h lower torso ischemia followed by 3 h of reperfusion: transgenic and wild type with sham-operated controls. Animals were then injected with ¹²⁵I bovine albumin. Heart was removed and samples from right and left ventricular free wall were harvested, weighted, and radioactivity was determined. Permeability index for wild-type animals in the RV was 0.22 ± 0.04, compared to 0.17 ± 0.07 in controls (NS), and in the LV 0.36 ± 0.08, compared to 0.21 ± 0.05 in controls (p < .01). The LV showed a significantly higher value compared to the right (0.22 ± 0.04 vs. 0.36 ± 0.08, p <.01). No difference was seen in the RV between transgenic and wild-type mice; however, in the LV the values decreased significantly in transgenic animals (p < .015). Thus, remote myocardial injury after lower torso I/R is present in both ventricles; however, the LV seems to be more susceptible as assessed by albumin permeability. Inhibition of the classic complement cascade may be a promising therapeutic approach for myocardial protection in reperfusion injury.