Changes In Prostaglandin E2 Levels Research Articles

Prostaglandin E2 mediates acid-induced heartburn in healthy volunteers

Prostaglandin E(2) (PGE(2)) plays a major role in pain processing and hypersensitivity. This study investigated whether PGE(2) levels are increased in the esophageal mucosa after acid infusion and whether increases in PGE(2) are associated with heartburn. Furthermore, expression of the PGE(2) receptor EP1 was investigated in human esophageal mucosa. Fourteen healthy male volunteers were randomized to 30-min lower esophageal acid (1% HCl) or saline perfusion. Before and after acid perfusion, endoscopic biopsies were taken from the distal esophagus. PGE(2) concentration (pg/mg protein) and EP1 mRNA and protein in biopsy samples were measured by ELISA, RT-PCR, and Western blotting. Symptom status of heartburn was evaluated with a validated categorical rating scale with a higher values corresponding to increasing intensity. PGE(2) levels in the esophageal mucosa significantly increased after acid infusion (before vs. after acid infusion: 23.2 ± 8.6 vs. 68.6 ± 18.3, P < 0.05), but not after saline infusion (before vs. after saline infusion: 9.3 ± 2.5 vs. 9.0 ± 3.2, NS). Time to first sensation (min) after acid infusion was less than after saline (saline vs. acid infusion: 22.1 ± 4.1 vs. 5.4 ± 1.5, P < 0.05). Intensity of heartburn in the acid-infusion group was also significantly greater compared with saline (saline vs. acid infusion: 54.3 ± 13.1 vs. 178.5 ± 22.8, P < 0.01). Changes in PGE(2) levels in the esophagus correlated with symptom intensity score (r = 0.80, P = 0.029). EP1 mRNA and protein expression were observed in the normal human esophageal mucosa. Esophageal PGE(2) expression is associated with mucosal acid exposure and heartburn.

Clinical findings and gingival crevicular fluid prostaglandin E2 and interleukin-1-beta levels following initial periodontal treatment and short-term meloxicam administration

Objective: To evaluate the effects of adjunctive meloxicam administration on clinical periodontal measurements and gingival crevicular fluid (GCF) prostaglandin E2 (PGE2) and interleukin-1-beta (IL-1β) levels in chronic periodontitis.Methods: Forty chronic periodontitis patients were randomized to receive either meloxicam 7.5 mg or placebo tablets for 10 days with scaling and root planing (SRP). GCF levels of PGE2 and IL-1β at baseline, day 10 of drug intake and 4 weeks after SRP were determined by enzyme-linked immunosorbent assay. Demographic, clinical periodontal data were analyzed using a repeated measures ANOVA and Bonferroni analysis. GCF PGE2 and IL-1β levels were compared between different evaluation times using the Friedman test. The Mann–Whitney test was used to compare biochemical data between the study groups. Pearson correlation analysis was used to relate clinical and biochemical data.Results: Study groups showed significant reductions in all clinical periodontal measurements and GCF volume (p < 0.05). In both groups, IL-1β was reduced significantly on day 10 and at week 4 compared with baseline (p < 0.01) without significant changes in PGE2 levels (p > 0.05). No significant differences were found between study groups in GCF IL-1β or PGE2 levels (p > 0.05).Conclusion: Adjunctive meloxicam does not seem to provide additional improvement in clinical parameters or GCF PGE2 and IL-1β levels. Larger-scale studies may better clarify potential usage of anti-inflammatory agents in periodontal therapy.

Abstract A29: Rectal mucosal polyamine and PGE2 levels and risk of colorectal adenomas in a phase IIb/III trial of combination difluoromethylornithine (DFMO) plus sulindac

Abstract Background: The pharmacologic targeting of polyamines and prostaglandin E2 (PGE2) has proven efficacy for colorectal adenoma prevention. However, the contribution of these analytes as biomarkers of drug response has not been investigated. Methods: We analyzed the relationships between rectal mucosal levels of polyamines (spermidine, spermine, and putrescine) and PGE2, treatment, and risk of adenoma within the context of a phase IIb/III trial of combination difluoromethylornithine (DFMO) plus sulindac for the prevention of colorectal adenoma. Results: We detected no differences in the change in PGE2 levels between the two groups for any time points, but we show a statistically significant decrease in spermidine:spermine levels and in putrescine levels in the DFMO/sulindac group at 12 and 36 months compared to the placebo arm. When we asked whether or not change in polyamine or putrescine levels was associated with adenoma recurrence in the treatment arm only, we found no difference in the rate of metachronous events by change in polyamine or PGE2 levels in the treatment arm. We also found no evidence that polyamine or PGE2 levels were associated with risk of adenoma when we restricted the analysis to the placebo arm only. Of interest, we found that participants with low baseline spermidine:spermine levels who received DFMO/sulindac achieved a significantly greater benefit from treatment (RR = 0.15, 95% CI = 0.06 to 0.40) than those with high baseline spermidine:spermine receiving drug (RR = 0.50, 95% CI = 0.27 to 0.92). Conclusions: DFMO/sulindac significantly suppressed the production of rectal mucosal polyamines, but the magnitude of change was not predictive of response to intervention. This was likely due to the large effect of DFMO/sulindac on adenoma recurrence. We found no evidence in the placebo arm that baseline polyamine or PGE2 were associated with the risk of developing adenoma. The modulating effect of baseline spermidine:spermine levels on metachronous adenoma, in those individuals receiving the drug combination, provides evidence of differential agent-effectiveness by steady-state polyamine levels that should be investigated in future studies. Citation Information: Cancer Prev Res 2010;3(1 Suppl):A29.

Effects of quercetin and β‐carotene supplementation on azoxymethane‐induced colon carcinogenesis and inflammatory responses in rats fed with high‐fat diet rich in ω‐6 fatty acids

Chronic inflammation in gastrointestinal tract has been suggested as a risk factor for tumor formation. The effect of dietary supplementation of quercetin or beta-carotene on colon carcinogenesis and inflammatory response in rats fed with high-fat diet rich in omega-6 fatty acids was assessed. Animals were exposed to two weekly subcutaneous injections of AOM (azoxymethane) at a single dose of 15 mg/kg body weight. A portion of rats from each group was sacrificed at 8 weeks after the last AOM treatment to determine ACF (aberrant crypt foci) formation. Colonic mucosa expression of iNOS (inducible nitric oxide) and COX-2 (cyclooxygenase-2) protein, and blood PGE2 (prostaglandin E2) level were measured. The remaining groups of animals were sacrificed at 33 weeks after the last AOM treatment to examine colon tumor formation. Rats on high-fat diet developed more aberrant crypt foci (P<0.05) compared with those of rats on regular diet. In the same vein, but in contrast to the effect seen with regular diet, the high-fat diet induced a significant up-regulation of iNOS expression. There was no significant change in the extent of COX-2 expression or in the PGE2 levels. Quercetin or beta-carotene supplementation reduced the number of ACF only in animals fed high-fat diet (p<0.05), however, no significant difference in tumor incidence was found. At week 33, the expression of iNOS was reduced by quercetin without a statistical significance, and COX-2 expression was slightly reduced in rats on beta-carotene supplementation. No change in PGE2 levels was observed. Whilst dietary antioxidants are considered as effective suppressors for precancerous lesion formation in colons exposed to high-risk diet, it is clear that elucidating the role of individual antioxidants in colon tumor formation coupled with an understanding of the molecular mechanisms involved would benefit colon cancer prevention strategies.

P-400 - Change in prostaglandin E2 levels during ulcer formation induced by ischemia-reperfusion in rats

P-400 - Change in prostaglandin E2 levels during ulcer formation induced by ischemia-reperfusion in rats

Control of Fetal Membrane Prostaglandin E2 Production by Bacteria

The effect of bacteria on the production of prostaglandin E2 (PGE2) and PGE2 metabolites by fetal membranes has been investigated. Live bacteria stimulated a large increase in the levels of PGE2 metabolites, but only a small increase in the levels of PGE2 on the fetal side of the membranes. No significant changes in the levels of PGE2 or its metabolites were found on the maternal side. Bacteria may therefore stimulate PGE2 production by fetal membranes during short-term incubations, but it seems that the metabolic capacity of the chorion was so high that no change in PGE2 levels was detectable on the maternal side of the fetal membranes. This was confirmed by the finding that less than 1% of 3H-PGE2 added to the fetal side of the membrane reached the maternal side without being metabolized.