Proton pump inhibitors, such as omeprazole (OPZ), lansoprazole and rabeprazole (RPZ), have been widely used as acid inhibitory agents for the treatment of upper gastrointestinal diseases. 1 OPZ is a substituted benzimidazole, which effectively inhibits gastric acid secretion by irreversibly binding to the proton pump (H + ,K + -ATPase) in gastric parietal cells, 2, 3 and is mainly metabolized by a genetically determined enzyme, S-mephenytoin-4¢-hydroxylase (CYP2C19), in the liver to hydroxyomeprazole (OH-OPZ). 4±8 OPZ is partially metabolized by CYP3A4 to omeprazole sulphone (OPZ-SFN), which is then metabolized to hydroxyomeprazole sulphone (OH-OPZ-SFN) by CYP2C19. 9 In individuals with a poor metabolizer (PM) phenotype or genotype of CYP2C19, the SUMMARY Background: Omeprazole is mainly metabolized in the liver by CYP2C19, a genetically determined enzyme, whereas rabeprazole is mainly reduced non-enzymatically and partially metabolized by CYP2C19. The therapeutic effects of rabeprazole are therefore assumed to be less affected by an individual's CYP2C19 status. Aim: To investigate the acid inhibitory effects and plasma levels of omeprazole and rabeprazole with reference to different CYP2C19 genotypes. Methods: Fifteen healthy volunteers took a daily dose of 20 mg of omeprazole or rabeprazole for 8 days. On postdose days 1 and 8, 24-h pro®les of intragastric pH were recorded and plasma concentrations of omeprazole, rabeprazole and their metabolites were determined.
Background-The circulating levels of secretory nonpancreatic type II phospholipase A 2 (sPLA 2 ) are increased in various chronic inflammatory diseases and the increase in the levels correlates with the disease severity. sPLA 2 may possibly play a role in atherogenesis and is highly expressed in atherosclerotic arterial walls that are known to have inflammatory features. Thus, this study prospectively examined whether circulating levels of sPLA 2 may have a significant risk and prognostic values in patients with coronary artery disease (CAD). Methods and Results-Plasma levels of sPLA 2 were measured in 142 patients with CAD and in 93 control subjects by a radioimmunoassay. The sPLA 2 levels had a significant and positive relations with serum levels of C-reactive protein, a marker of systemic inflammation, and with the number of the traditional coronary risk factors associated with individuals. Multivariate logistic regression analysis showed that higher levels of sPLA 2 (Ͼ246 ng/dL; 75th percentile of sPLA 2 distribution in controls) were a significant and independent risk factor for the presence of CAD. In multivariate Cox hazard analysis, the higher levels of sPLA 2 were a significant predictor of developing coronary events (ie, coronary revascularization, myocardial infarction, coronary death) during a 2-year follow-up period in patients with CAD independent of other risk factors, including CRP levels, an established inflammatory predictor. Conclusions-The increase in circulating levels of sPLA 2 is a significant risk factor for the presence of CAD and predicts clinical coronary events independent of other risk factors in patients with CAD; these results may reflect possible relation of sPLA 2 levels with inflammatory activity in atherosclerotic arteries. (Circulation. 1999;100:1280-1284.)
The results indicate that vitamin E treatment improved endothelium-dependent vasodilation and decreased plasma TBARS levels in patients with CSA. Thus, increased oxidative stress may contribute to endothelial dysfunction and anginal attacks in patients with CSA.
Statins are cholesterol-lowering drugs that have been reported to promote bone formation. The purpose of this study was to investigate the effect of simvastatin on the enhancement of bone formation around titanium implants. Thirty-week-old female rats received pure titanium implants in both tibiae. The animals were intra-peritoneally administered 0, 0.125, 1, 5 or 10 mg kg(-1) of simvastatin daily. After 30 days, the animals were sacrificed, and specimens were prepared. The bone contact ratio of the implant, bone density in the medullary canal and percentage of cortical bone were obtained. Markers for bone turnover were also measured using sera collected at the time of euthanasia. In the medullary canal, a scanty amount of bone was observed in the 0, 0.125 and 1 mg kg(-1) groups. In contrast, in both the 5 and 10 mg kg(-1) groups, thicker bone trabeculae were abundant. Histometric observations showed that the bone contact ratio and the bone density of both groups were significantly greater than those of the other groups (anova, P < 0.01). However, no significant difference in the percentage of cortical bone was found between groups. Serum chemistry showed that statin increased bone formation markers and decreased bone resorption markers. In conclusion, although the dose equivalent to that used in human patients with hypercholesterolemia was not effective, a simvastatin dose of 5 mg kg(-1) or higher increased medullary bone formation around the titanium. In contrast, no effect of simvastatin on pre-existing cortical bone was indicated.
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