Soluble Guanylate Cyclase Activation during Ischemic Injury in Mice Protects against Postischemic Inflammation at the Mitochondrial Level

Abstract

Previous studies showed that soluble Guanylate Cyclase (sGC) activation with BAY 60 protected against postischemic inflammation when injected as a preconditioning agent in wild type (WT) H129 and heme‐oxygenase‐1 KO (HO‐1‐/‐) mice. This occurred when given both 10 min and 24 hours prior to ischemia (Wang et al. AJP Heart Circ Physiol 305:H521‐H532, 2013). We hypothesized that the same protective effect would occur when BAY 60 is administered during ischemia. When tested we observed reduced postischemic leukocyte rolling (LR) and leukocyte adhesion (LA) to intestinal venules in WT and HO‐1‐/‐ mice, as well as prevention of increased TNF‐α and circulating neutrophil levels that accompany ischemia/reperfusion (I/R). Based on these findings, we further hypothesized that BAY 60 when given during ischemia would prevent intestinal mucosal mitochondrial dysfunction induced by I/R. Mitochondrial integrity was evaluated by the Calcein AM fluorescence method (used to measure mitochondrial permeability), and the JC‐1 fluorescence ratio (used to measure mitochondrial membrane potential). Both mitochondrial permeability and membrane potential were disrupted following I/R, which indicates the formation of mitochondrial permeability transition pores (mPTP). However, both Calcein fluorescence and JC‐1 fluorescence ratio were maintained at control levels in cells from the mice that were treated with BAY 60. Our results indicate that sGC activation during ischemia protects against I/R inflammatory processes and preserves mucosal mitochondrial function by preventing mPTP formation Supported by: HL095486 & AA14945. Bayer Schering Pharma AG provided BAY 60 as a gift.