title: Delayed preconditioning induced by lipoteichoic acid from B. subtilis and S. aureus is not blocked by administration of 5-hydroxydecanoate.
abstract: Bacterial walls contain lipopolysaccharide (LPS), lipoteichoic acid (LTA), or peptidoglycan. Pretreatment of rats with low doses of LPS (from E. coli) or LTA (from S. aureus, a pathogenic gram-positive bacterium) for 16-24 h reduces myocardial infarct size caused by a subsequent period of myocardial ischemia-reperfusion. This phenomenon of enhanced tolerance to an ischemic insult has been termed delayed preconditioning (DP). The aim of this study was to investigate whether LTA from B. subtilis (a nonpathogenic gram-positive bacterium) induces DP when administered 16 h before left anterior descending coronary artery (LAD) occlusion-reperfusion in the rat. Furthermore, we investigated whether the specific mitochondrial K(ATP) (mitoK(ATP)) channel inhibitor 5-hydroxydecanoate (5-HD, 5 mg/kg) blocks DP afforded by LTA of both strains of bacteria. Male Wistar rats were subjected to LAD occlusion-reperfusion (25-120 min) and infarct size was determined. In rats pretreated with saline (1 mL/kg i.p.), LAD occlusion-reperfusion resulted in an infarct size of 58%. Pretreatment of animals with LTA (S. aureus, 1 mg/kg i.p.) or LTA (B. subtilis, 1 mg/kg i.p.) reduced infarct size by 22% or 33%, respectively. Administration of 5-HD 10 min before LAD occlusion-reperfusion did not abolish DP afforded by LTA from S. aureus or B. subtilis, respectively. These results imply that late (after 16 h) opening of the mitoK(ATP) channel is not part of the signaling pathway of LTA-induced DP.
authors.affiliation: Department of Cardiac, Vascular, and Inflammation Research, The William Harvey Research Institute, St. Bartholomew's and The Royal London School of Medicine and Dentistry, United Kingdom.
authors.forename: Kai
authors.initials: K
authors.lastname: Zacharowski
authors.forename: Prabal K
authors.initials: PK
authors.lastname: Chatterjee
authors.forename: Christoph
authors.initials: C
authors.lastname: Thiemermann
mesh_terms: D000818:Animals; D001412:Bacillus subtilis; D003652:Decanoic Acids / Q000494:pharmacology*; D006439:Hemodynamics / Q000187:drug effects; D006880:Hydroxy Acids / Q000494:pharmacology*; D019157:Ischemic Preconditioning, Myocardial; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008297:Male; D009203:Myocardial Infarction / Q000097:blood / Q000473:pathology* / Q000517:prevention & control*; D015428:Myocardial Reperfusion Injury / Q000097:blood / Q000473:pathology / Q000517:prevention & control; D051381:Rats; D017208:Rats, Wistar; D015398:Signal Transduction / Q000187:drug effects; D013211:Staphylococcus aureus; D013682:Teichoic Acids / Q000494:pharmacology*
chemical_list: D003652:Decanoic Acids; D006880:Hydroxy Acids; D008070:Lipopolysaccharides; D013682:Teichoic Acids; C009900:lipoteichoic acid; C052853:5-hydroxydecanoic acid