Male Wistar rats were divided into three groups, a control group (CO) and two OFO-fed groups (OF and OFE). The diet of the OFE group was supplemented with an extra 50 mg/kg of alpha-tocopherol acetate and thus contained twice as much vitamin E as that of the OF group. After six weeks on these
diets, liver alpha-tocopherol levels in the OF group were selleck chemicals the significantly lowest among the three groups. Excretion of the alpha-tocopherol metabolite, alpha-carboxyethyl hydroxychroman (alpha-CEHC) in the urine was significantly lower in the OF group than in the other two groups. There were no significant differences in protein levels of alpha-tocopherol transfer protein (alpha-TTP) and multidrug resistance protein among the three groups. Protein levels of cytochrome P450 monooxygenase (CYP) 3A, CYP4A, and catalase were markedly increased in both groups on the OFO diet. This suggests that an OFO diet may RG-7388 clinical trial interfere with medicine metabolism and needs further investigation.”
“Background: Fesoterodine is a new antimuscarinic agent developed for the treatment of overactive bladder. Fesoterodine itself is
inactive and is rapidly and extensively converted by ubiquitous esterases to its principal active moiety, 5-hydroxymethyl tolterodine (5-HMT). 5-HMT is formed via biotransformation of both fesoterodine and tolterodine, albeit by different metabolising enzymes, viz. esterases and CYP2D6 respectively. Tolterodine is a potent muscarinic receptor Selisistat clinical trial antagonist and has been used for the treatment of overactive bladder for over ten years. The objective of this study was to establish the pharmacokinetic profile of fesoterodine and to highlight its potential pharmacokinetic advantages over tolterodine.
Design: Single-centre, open-label, randomised, 4-way crossover study in a total of 24 healthy male volunteers. Single oral doses of 4, 8, or 12 mg fesoterodine were administered after an overnight fast. In addition, the 8 mg dose was also administered after a standard high-fat and high-calorie break-fast. Blood and
urine samples for the analysis of 5-HMT were collected before and multiple times after drug administration for pharmacokinetic analysis.
Results: The mean peak plasma concentration of 5-HMT and the mean area under the time versus concentration curve (AUC) increased proportionally with the fesoterodine dose. These two parameters were some 2-fold higher in CYP2D6 poor metabolisers, whereas the time to peak plasma concentration (t(max)) and half life (t(1/2)) were not influenced by the dose or the CYP2D6 metaboliser status. If fesoterodine was taken following a high-fat break-fast, we observed small increases in C(max) and AUC. In spite of these modest genetic influences and food effects on the pharmnacokinetics of fesoterodine, the overall interindividual variability in C(max) levels was relatively little compared to previously published reports using tolterodine.