Altered Cardiac Gene Expression During E. coli Porcine Peritonitis

Cardiac dysfunction is a feature of porcine peritonitis. In order to gain insight into the fundamental mechanisms of this phenotype, gene expression analysis (Affymetrix) was applied to serial cardiac biopsies of sham (n=2) and E. coli infected pigs (n=3). Cardiac samples were taken at basal and hourly after infection. Sham pigs had stable heart rate, cardiac output (CO) and core temperature for the 5 hr period; infected pigs demonstrated an early elevation in CO and ventricular shortening and/or ejection (assessed by echocardiography) followed by development of hypodyanmics. Genes were determined to be differentially regulated at a greater than or less than twofold change and p<0.05. In infected animals, increasing numbers of genes were up‐ or down‐regulated (36, 278, 514, 842 and 1238 at 1, 2, 3, 4 and 5 hr) whereas sham infection altered fewer (247, 67 and 384 genes at 2, 3, 4 hr) Comparing sham vs infected animals at the same time, numbers of significantly altered genes increased with time (32 at basal, to 74, 189 and 601 at 2, 3, and 4 hr post infection.) These results will provide biomarker and mechanistic insights to pathogenesis of cardiac dysfunction of septic peritonitis and may also help identify some altered novel gene transcription pathways that can serve as new targets for diagnostic tools and therapeutic strategies. All candidate genes will be validated by quantitative PCR.