|
|
||||||||
1Second Department of Medicine, Kyoto Prefectural University of Medicine, Kyoto 602-8566; 2Department of Clinical Pharmacology, Kyoto Pharmaceutical University, Kyoto 607-8414, Japan; and 3Department of Molecular and Cellular Medicine, University of Ottawa, Ottawa, Ontario, Canada K1H 8M5
Submitted 29 January 2003 ; accepted in final form 2 September 2003
The mechanisms by which endotoxemia causes cardiac depression have not been fully elucidated. The present study examined the involvement of nitric oxide (NO) in this pathology. Rats were infused with lipopolysaccharide (LPS) or saline, and the plasma and myocardial
and
(NOx) concentrations were measured before or 3, 6, and 24 h after treatment. The hearts were then immediately isolated and mounted in a Langendorff apparatus, and left ventricular developed pressure (LVDP) was determined before biochemical analysis of the myocardium. LPS injection effected the expression of inducible NO synthase (iNOS) in the myocardium, a marked increase in plasma and myocardial NOx levels, and a significant decline in LVDP compared with saline controls. The LPS-induced NO production and concomitant cardiac depression were most pronounced 6 h after LPS injection and were accompanied by a significant increase in myocardial cGMP content. Myocardial ATP levels were not significantly altered after LPS injection. Significant negative correlation was observed between LVDP and myocardial cGMP content, as well as between LVDP and plasma NOx levels. Aminoguanidine, an inhibitor of iNOS, significantly attenuated the LPS-induced NOx production and contractile dysfunction. Furthermore, 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one, an inhibitor of soluble guanylate cyclase, significantly decreased myocardial cGMP content and attenuated the contractile depression, although aminoguanidine or 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one was not able to completely reverse myocardial dysfunction. Our data suggest that endotoxin-induced contractile dysfunction in rat hearts is associated with NO production by myocardial iNOS and a concomitant increase in myocardial cGMP.
contractile function; septic shock; nitric oxide synthase
This article has been cited by other articles:
![]() |
S. N. Mink, K. Kasian, L. E. Santos Martinez, H. Jacobs, R. Bose, Z.-Q. Cheng, and R. B. Light Lysozyme, a mediator of sepsis that produces vasodilation by hydrogen peroxide signaling in an arterial preparation Am J Physiol Heart Circ Physiol, April 1, 2008; 294(4): H1724 - H1735. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. N. Mink, Z.-Q. Cheng, R. Bose, H. Jacobs, K. Kasian, D. E. Roberts, L. E. Santos-Martinez, and R. B. Light Lysozyme, a mediator of sepsis, impairs the cardiac neural adrenergic response by nonendothelial release of NO and inhibitory G protein signaling Am J Physiol Heart Circ Physiol, November 1, 2007; 293(5): H3140 - H3149. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |