QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: jpet.103.051805v1 306/2/538    most recent Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Farmer, M. R. Articles by Ralevic, V. Search for Related Content PubMed PubMed Citation Articles by Farmer, M. R. Articles by Ralevic, V.

CARDIOVASCULAR

Effects of in Vivo Lipopolysaccharide Infusion on Vasoconstrictor Function of Rat Isolated Mesentery, Kidney, and Aorta

School of Biomedical Sciences, University of Nottingham Medical School, Queen's Medical Centre, Nottingham, United Kingdom

Continuous infusion of lipopolysaccharide (LPS) into conscious rats elicits regionally selective cardiovascular disturbances. The aim of the present study was to assess contractile function in different vascular preparations (renal, mesenteric, and thoracic aorta) taken from rats infused with LPS for 2 or 24 h. Sustained responses to continuous infusion of methoxamine but not to KCl were reduced in the aorta (at 2 and 24 h LPS) and mesentery (at 24 h LPS) but not in the renal vascular bed. In contrast, transient responses to bolus doses of methoxamine were unchanged in the mesentery. In Ca²⁺-imaging experiments with fura-2, challenge with a single concentration of methoxamine (10 µM, which showed an impaired contractile response at 24 h LPS) induced a rise in intracellular Ca²⁺ in the mesenteric artery that was not different from the control. Furthermore, in the aorta, the contractile response to caffeine was attenuated only in the 2 h LPS group. These results show that there is regional heterogeneity in in vitro vascular responsiveness in preparations taken from LPS-infused rats. Thus, in mesenteric beds and aortae, but not renal beds, there is hypocontractility to methoxamine that is not due to a generalized inability of the smooth muscle to contract, which is evident with sustained but not transient application of agonist (mesentery) and which, in late endotoxemia (24 h LPS), does not appear to involve abnormalities in Ca²⁺ mobilization or entry.

Address correspondence to: Dr. Vera Ralevic, School of Biomedical Sciences, University of Nottingham Medical School, Queen's Medical Centre, Clifton Boulevard, Nottingham, NG7 2UH, United Kingdom. E-mail: vera.ralevic{at}nottingham.ac.uk

This article has been cited by other articles:

				J.-J. Boffa and W. J. Arendshorst Maintenance of Renal Vascular Reactivity Contributes to Acute Renal Failure during Endotoxemic Shock J. Am. Soc. Nephrol., January 1, 2005; 16(1): 117 - 124. [Abstract] [Full Text] [PDF]

				J.-J. Boffa, A. Just, T. M. Coffman, and W. J. Arendshorst Thromboxane Receptor Mediates Renal Vasoconstriction and Contributes to Acute Renal Failure in Endotoxemic Mice J. Am. Soc. Nephrol., September 1, 2004; 15(9): 2358 - 2365. [Abstract] [Full Text] [PDF]

				T. Bennett, R. P. Mahajan, J. E. March, P. A. Kemp, and S. M. Gardiner Regional and temporal changes in cardiovascular responses to norepinephrine and vasopressin during continuous infusion of lipopolysaccharide in conscious rats Br. J. Anaesth., September 1, 2004; 93(3): 400 - 407. [Abstract] [Full Text] [PDF]