Uropathogenic Escherichia coli alters muscle contractions in rat urinary bladder via a nitric oxide synthase-related signaling pathway
Journal
Journal of Infectious Diseases
Journal Volume
194
Journal Issue
12
Pages
1774-1782
Date Issued
2006
Author(s)
Abstract
Background. Uropathogenic Escherichia coli (UPEC) is a common cause of urinary-tract infection. The mechanisms by which bacteria cause the symptoms of cystitis remain unclear. Methods. The contractions of isolated rat detrusor strips evoked by electrical field stimulations (EFS) or by exogenous agonists and immunoblotting for the detection of protein expression in the bladder were measured in the short (1 h) and long (24 h) term after the intravesical instillation of [96 (O4:K6) strain or UPEC isolated from patients with acute E. coli pyelonephritis or E. coli lipopolysaccharide (LPS). Results. One hour after the instillation of UPEC, the level of endothelial nitric oxide synthase (eNOS) and the contractile response, but not protein kinase C (PKC) and extracellular signal-regulated kinase (ERK)-1/2 activation, were higher. Twenty-four hours after UPEC treatment, detrusor contractions were decreased, and inducible (i) NOS protein expression and ERK1/2 phosphorylation, but not PKC activation, were observed. Both aminoguanidine and PD98059 treatment markedly reversed the decrease of EFS- and acetylcholine-evoked detrusor contractions induced by UPEC. The instillation of LPS triggered PKC activation but not ERK1/2 phosphorylation. Conclusions. Short-term intravesical instillation of UPEC enhances detrusor contractions through an eNOS-related pathway, but iNOS-regulated ERK1/2 signaling may be involved in long-term UPEC treatment-induced responses. There are different mechanisms involved in the responses induced by UPEC and EPS. ? 2006 by the Infectious Diseases Society of America. All rights reserved.
SDGs
Other Subjects
2 (2 amino 3 methoxyphenyl)chromone; acetylcholine; aminoguanidine; endothelial nitric oxide synthase; inducible nitric oxide synthase; lipopolysaccharide; mitogen activated protein kinase 1; mitogen activated protein kinase 3; n(g) nitroarginine methyl ester; nitric oxide synthase; protein kinase C; animal experiment; animal model; article; bacterial infection; bladder contraction; bladder muscle; controlled study; cystitis; detrusor muscle; enzyme phosphorylation; Escherichia coli; female; Gram negative infection; inflammation; nonhuman; nucleotide sequence; priority journal; protein expression; pyelonephritis; rat; reverse transcription polymerase chain reaction; signal transduction; urinary tract infection; urine level; Western blotting; Animals; Disease Models, Animal; Escherichia coli; Escherichia coli Infections; Female; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Muscle Contraction; Muscle, Smooth; Nitric Oxide Synthase; Phosphorylation; Rats; Rats, Wistar; Signal Transduction; Urinary Bladder; Urinary Tract Infections
Type
journal article