Lipopolysaccharide from Escherichia coli prevents indomethacin-induced gastric damage in rats: role of non-protein sulfhydryl groups and leukocyte adherence
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Objective and design
To investigate the role of non-protein sulfhydryl groups (NP-SH) and leukocyte adhesion in the protective effect of lipopolysaccharide (LPS) from Escherichia coli against indomethacin-induced gastropathy.
Materials or subjects
Male Wistar rats were divided into four groups: saline, LPS, saline + indomethacin and LPS + indomethacin, with six rats in each group.
Rats were pretreated with LPS (300 μg/kg, by intravenous) or saline. After 6 h, indomethacin was administered (20 mg/kg, by gavage).
Three hours after treatments, rats were killed. Macroscopic gastric damage, gastric NP-SH concentration, myeloperoxidase (MPO) activity and mesenteric leukocyte adhesion (intravital microscopy) were assessed. Statistical analysis was performed using one-way analysis of variance followed by the Newman–Keuls test. Statistical significance was set at P < 0.05.
LPS reduced the gastric damage, gastric MPO activity and increased gastric NP-SH concentration in indomethacin-induced gastropathy. LPS alone increased gastric NP-SH when compared to saline. Indomethacin increased leukocyte adhesion when compared to the saline, and LPS reduced indomethacin-induced leukocyte adhesion. In addition, LPS alone did not change leukocyte adhesion, when compared to the saline.
LPS protective effect against indomethacin-induced gastropathy is mediated by an increase in the NP-SH and a decrease in leukocyte–endothelial adhesion.
KeywordsLPS GI damage NSAIDs Leukocyte adhesion
Non-steroidal anti-inflammatory drugs
Nitric oxide synthase
Inducible nitric oxide synthase
Non-protein sulfhydryl groups
The authors gratefully acknowledge the technical assistance of Maria Silvandira Freire França. Grants from CNPq (Brazil) supported this work. Dr. Cunha and Dr. Souza are recipients of a CNPq fellowship. This work is part of the requirements to obtain a Master of Science degree in Pharmacology at the School of Medicine, Federal University of Ceara by one of us (A.S. Gomes).
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