Urinary Excretion Of Metabolites Research Articles

Productive performance and urinary excretion of mimosine metabolites by hair sheep grazing in a silvopastoral system with high densities of Leucaena leucocephala

The aim of this study was to evaluate daily weight gain (DWG), total dry matter (DM) intake, rumen degradability of forage, and urinary excretion of mimosine metabolites by hair sheep in a silvopastoral system with high densities of Leucaena leucocephala. A completely randomized design was carried out with two treatments: treatment 1 (T1) silvopastoral system with leucaena at a density of 35,000 plants/ha and treatment 2 (T2), leucaena at a density of 55,000 plants/ha. Leucaena was associated with tropical grasses Panicum maximum and Cynodon nlemfluensis. Twenty-four male Pelibuey lambs of 23.2 ± 3.4 kg live weight (LW) were used (12 lambs per treatment). Results showed differences (P < 0.05) in DWG of T1 (106.41 ± 11.66 g(-1) sheep(-1)) with respect to that of T2 (81.33 ± 11.81 g(-1) sheep). Voluntary intake was higher in lambs from T1 (83.81 ± 04.07 g DM/kg LW(0.75)) with respect to that from T2 (71.67 ± 8.12 g DM/kg LW(0.75)). There was a difference in color of urine between sheep of T1 and T2, the latter giving positive results for the presence of metabolites derived from mimosine (3-4 dihydroxypyridine and 2-3 dihydroxy pyridone). Rumen degradability of DM of L. leucocephala was higher (P < 0.05) compared to that of P. maximum and C. nlemfluensis (72.94 ± 0.40 vs. 67.06 ± 1.50 and 63.25 ± 1.51 %, respectively). It is concluded that grazing at high densities of L. leucocephala affects daily weight gain of hair sheep, possibly due to ingestion of high amounts of mimosine which may exert an adverse effect on voluntary intake.

Variability on urinary excretion of chlorogenic acid compounds and metabolites in humans after overnight fasting and under controlled diets

Large intra‐ and inter‐individual variabilities have been observed in previous studies evaluating polyphenols bioavailability in humans. The present study evaluated the intra‐ and inter‐individual variations on the urinary excretion of chlorogenic acids (CGA) and metabolites in adults (n=12), in 5 separate days, after 10h fasting and a 48h controlled phenolic free‐diet. A total of 22 compounds (359.74 ± 197.90 μmol) were identified in urine by HPLC/MS, including 6 CGA and 16 phenolic acids, varying from 1 to 10 fold for the same subject intra‐day. Only 0.36 ± 0.35 μmol of total CGA were excreted in urine, varying from 1 to 7 fold for the same subject intra‐day. A large inter‐individual variation was also observed for all compounds. The largest variation was observed for p‐coumaric acid, followed by 4‐caffeoylquinic and 3‐(4’‐hydroxyphenyl) propionic acids, whereas benzoic, hippuric and 2,4‐dihydroxybenzoic acids showed the lowest variation. The patterns of CGA and metabolites excretion were also remarkably different among subjects, but remained similar in different days for the same subjects. Concluding, the inter‐individual variability on CGA metabolism seems to be more expressive when compared to intra‐individual variability. Our results also suggest the need for long washout periods for CGA and that their metabolization routs may vary according to individuals, which should be thoroughly investigated. Financial Support: CNPQ and FAPERJ.

Exposure and Kinetics of Polycyclic Aromatic Hydrocarbons (PAHs) in Cigarette Smokers

Our study objectives were (1) to investigate the selectivity of polycyclic aromatic hydrocarbon (PAH) metabolites for tobacco smoke exposure and (2) to determine half-lives of PAH metabolites in smokers. There were 622 participants from the United States (US) and Poland, and of these, 70% were smokers. All subjects provided spot urine samples, and 125 smokers provided blood samples. Urinary PAH metabolite half-lives were determined in 8 smokers. In controlled hospital studies of 18 smokers, the associations between various measures of nicotine intake and urinary excretion of PAH metabolites were investigated. Plasma nicotine was measured by GC. LC-MS/MS was used to measure the plasma levels of cotinine and trans-3'-hydroxycotinine, and urine levels of nicotine and its metabolites, total 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) and PAH metabolites (2-naphthol, 1-, 2-, and 3-hydroxyfluorenes, 1-, 2-, 3-, and 4-hydroxyphenanthrenes, and 1-hydroxypyrene). Regardless of smoking status, PAH metabolite excretion was higher in Polish subjects than in US subjects (p-values <0.001). 1-Hydroxyfluorene exhibited the greatest difference between smokers and nonsmokers, with a 5-fold difference in Polish subjects and a 25-fold difference in US subjects, followed by 3- and 2-hydroxyfluorenes, 2-naphthol, and 1-hydroxypyrene. The differences for hydroxyphenanthrenes were small or nonsignificant. 1-Hydroxyfluorene had the highest correlation with urine nicotine equivalents (r = 0.77) and urine NNAL (r = 0.64). While the half-lives of PAH metabolites were <10 h in smokers, 1-hydroxyfluorene had the largest ratio of initial to terminal urine concentration (58.4 ± 38.6, mean ± SD) after smoking. Receiver Operating Characteristic (ROC) analysis of PAHs among Polish and US subjects further showed that hydroxyfluorenes are most highly discriminative of smokers from nonsmokers followed by 2-naphthol and 1-hydroxypyrene. In conclusion, hydroxyfluorenes, particularly 1-hydroxyfluorene, and 2-naphthol are more selective of tobacco smoke than 1-hydroxypyrene and hydroxyphenanthrenes. Characterization of hydroxyfluorene and 2-naphthol metabolites in urine may improve the characterization of PAHs from tobacco smoke and related disease risks among smokers and nonsmokers.

Preoperative Embolization Reduces the Risk of Cathecolamines Release at the Time of Surgical Excision of Large Pelvic Extra-Adrenal Sympathetic Paraganglioma

A 30-year-old woman with severe hypertension was admitted to the hospital with a history of headache, palpitations, and diaphoresis following sexual intercourse. Twenty-four hour urinary excretion of free catecholamines and metabolites was markedly increased as was serum chromogranin A. Computed tomography scan revealed a large mass in the left adnex site and magnetic resonance imaging confirmed the computer tomography finding, suggesting the presence of extra-adrenal sympathetic paraganglioma. I-metaiodobenzyl guanidine scintigram revealed an increased uptake in the same area. Transcatheter arterial embolization of the mass resulted in marked decreases in blood pressure and urinary excretion of free catecholamines and metabolites. Surgical excision of the mass was then accomplished without complication. Preoperative embolization is a useful and safe procedure which may reduce the risk of catecholamines release at the time of surgical excision in large pelvic extra-adrenal sympathetic paraganglioma.

褐色細胞腫に対する腹腔鏡下手術の臨床的検討―手術時間と術中高血圧に影響する術前の臨床パラメーターの解析―

We retrospectively analyzed the preoperative clinical parameters which influence operative time and intraoperative maximum systolic blood pressure in patients undergoing laparoscopic adrenalectomy for pheochromocytoma. Between January 1992 and September 2010, we performed 28 laparoscopic adrenalectomies for pheochromocytoma at Hamamatsu University School of Medicine. These 28 cases were characterized based on the following parameters: body mass index (BMI), tumor size, history of hypertension, preoperative blood pressure, serum concentration of catecholamine, and 24-h urinary excretion of catecholamine metabolite. We retrospectively analyzed whether or not these parameters influenced operative time or intraoperative maximum systolic blood pressure. All 28 cases of laparoscopic adrenalectomy were performed safely and without intraoperative complications and needed neither blood transfusion nor conversion to laparotomy. The median operative time was 203 minutes, and intraoperative hypertension (systolic blood pressure > 200 mmHg) occurred in 46% (13/28) of cases. Median day of discharge in all patients was post-operative day 5. Significant positive correlation was shown between tumor size and operative time and between intraoperative maximum systolic blood pressure and serum concentration of catecholamine or 24-h urinary excretion of catecholamine metabolite (p < 0.05). The lengthened operative time for large tumors and elevated intraoperative blood pressure for tumors with high preoperative catecholamine activity necessitate careful perioperative management in patients receiving laparoscopic adrenalectomy for pheochromocytoma.

Urinary excretion of bilirubin oxidative metabolites in arsenite-treated mice

Human exposure to inorganic arsenic (iAsIII), a potent oxidative stressor, causes liver injuries, which can lead to cancer. It is known that induction of haem oxygenase-1 (HMOX1) reduces arsenite-induced cytotoxicity in the liver. In a two-step reaction HMOX1 generates BR from haem and BR, in turn is oxidised to its oxidative metabolites by radical oxygen species (ROS). Bilirubin oxidative metabolites (BOMs), such as tripyrroles and propentdyopent have been identified and measured in rat and human urine. Additionally, two novel dipyrroles (with m/z values 333 and 315) have recently been identified in vitro (Abu-Bakar et al. (2011). Toxicol. Appl. Pharmacol., 257, 14-22) but their presence in biological samples has yet to be demonstrated. The aim of the present study was to identify the novel dipyrroles in urine of control and iAsIII treated mice. Acute iAsIII exposure generated transient oxidative stress in the liver, which associated with temporal induction of hepatic HMOX1, the rate-limiting enzyme of BR biosynthesis. The increase in the total BR levels was modest compared to the strong induction of HMOX1. Additionally, urinary dipyrroles (m/z values 333 and 315) escalated after iAsIII exposure. The results suggest that dipyrrolic BOMs can be used as marker for oxidative stress.

Subtotal nephrectomy plus coronary ligation leads to more pronounced damage in both organs than either nephrectomy or coronary ligation

Coexistence of chronic kidney disease (CKD) and heart failure (HF) in humans is associated with poor outcome. We hypothesized that preexistent CKD worsens cardiac outcome after myocardial infarction, and conversely that ensuing HF worsens progression of CKD. Subtotally nephrectomized (SNX) or sham-operated (CON) rats were subjected to coronary ligation (CL) or sham surgery in week 9 to realize four groups: CON, SNX, CON + CL, and SNX + CL. Blood pressure and renal function were measured in weeks 8, 11, 13, and 15. In week 16, cardiac hemodynamics and end-organ damage were assessed. Blood pressure was significantly lower in SNX + CL vs. SNX. Despite this, glomerulosclerosis was more severe in SNX + CL vs. SNX. Two weeks after CL, SNX + CL had more cardiac dilatation compared with CON + CL (end-diastolic volume index: 0.28 ± 0.04 vs. 0.19 ± 0.03 ml/100 g body wt; mean ± SD, P < 0.001), although infarct size was similar. During follow-up in SNX + CL, ejection fraction declined. Mortality was only observed in SNX + CL (2 out of 9). In SNX + CL, end-diastolic pressure (18 ± 4 mmHg) and tau (29 ± 9 ms), the time constant of active relaxation, were significantly higher compared with SNX (13 ± 3 mmHg, 20 ± 4 ms; P < 0.01) and CON + CL (11 ± 5 mmHg, 17 ± 2 ms; P < 0.01). The diameter of small arterioles in the myocardium was significantly decreased in SNX + CL vs. CON + CL (P < 0.01). Urinary excretion of NO metabolites was significantly lower in SNX + CL compared with both CL and SNX. This study demonstrates the existence of more heart and more kidney damage in a new model of combined CKD and HF than in the individual models. Such enhanced damage appears to be separate from systemic hemodynamic changes. Reduced nitric oxide availability may have played a role in both worsened glomerulosclerosis and cardiac diastolic function and appears to be a connector in the cardiorenal syndrome.

Metabolomic analysis reveals differences in urinary excretion of kiwifruit-derived metabolites in a mouse model of inflammatory bowel disease

The interleukin-10-deficient (IL-10(-/-)) mouse, a model of inflammatory bowel disease (IBD), develops intestinal inflammation unless raised in germ-free conditions. The metabolic effects of consuming extracts from the fruits of yellow (Actinidia chinensis) or green-fleshed (A. deliciosa) kiwifruit that displayed in vitro anti-inflammatory activity were investigated in IL-10(-/-) mice by metabolomic analysis of urine samples. Kiwifruit-derived metabolites were detected at significantly higher levels in urine of IL-10(-/-) mice relative to those of wild-type mice, indicating that the metabolism of these metabolites was affected by IL-10(-/-)-wild-type genotypic differences. Urinary metabolites previously associated with inflammation were not altered by the kiwifruit extracts. This study demonstrates the use of metabolomic analysis to study dietary effects and the influence of genotype on food metabolism, which may have implications on the development of functional foods for the treatment of IBD.

Trends of the internal phthalate exposure of young adults in Germany—Follow-up of a retrospective human biomonitoring study

The exposure of the general population to phthalates is of increasing public health concern. Variations in the internal exposure of the population are likely, because the amounts, distribution and application characters of the phthalate use change over time. Estimating the chronological sequences of the phthalate exposure, we performed a retrospective human biomonitoring study by investigating the metabolites of the five most prominent phthalates in urine. Therefore, 24h-urine samples from the German Environmental Specimen Bank (ESB) collected from 240 subjects (predominantly students, age range 19-29 years, 120 females, 120 males) in the years 2002, 2004, 2006 and 2008 (60 individuals each), were analysed for the concentrations of mono-n-butyl phthalate (MnBP) as metabolite of di-n-butyl phthalate (DnBP), mono-iso-butyl phthalate (MiBP) as metabolite of di-iso-butyl phthalate (DiBP), mono-benzyl phthalate (MBzP) as metabolite of butylbenzyl phthalate (BBzP), mono-(2-ethylhexyl) phthalate (MEHP), mono-(2-ethyl-5-hydroxyhexyl) phthalate (5OH-MEHP), mono-(2-ethyl-5-oxohexyl) phthalate (5oxo-MEHP), mono-(2-ethyl-5-carboxypentyl) phthalate (5cx-MEPP) and mono-(2-carboxymethyl hexyl) phthalate (2cx-MMHxP) as metabolites of di(2-ethylhexyl) phthalate (DEHP), monohydroxylated (OH-MiNP), monooxidated (oxo-MiNP) and monocarboxylated (cx-MiNP) mono-iso-nonylphthalates as metabolites of di-iso-nonyl phthalates (DiNP). Based on the urinary metabolite excretion, together with results of a previous study, which covered the years 1988-2003, we investigated the chronological sequences of the phthalate exposure over two decades. In more than 98% of the urine samples metabolites of all five phthalates were detectable indicating a ubiquitous exposure of people living in Germany to all five phthalates throughout the period investigated. The medians in samples from the different years investigated are 65.4 (2002), 38.5 (2004), 29.3 (2006) and 19.6 μg/l (2008) for MnBP, 31.4 (2002), 25.4 (2004), 31.8 (2006) and 25.5 μg/l (2008) for MiBP, 7.8 (2002), 6.3 (2004), 3.6 (2006) and 3.8 μg/l (2008) for MBzP, 7.0 (2002), 5.6 (2004), 4.1 (2006) and 3.3 μg/l (2008) for MEHP, 19.6 (2002), 16.2 (2004), 13.2 (2006) and 9.6 μg/l (2008) for 5OH-MEHP, 13.9 (2002), 11.8 (2004), 8.3 (2006) and 6.4 μg/l (2008) for 5oxo-MEHP, 18.7 (2002), 16.5 (2004), 13.8 (2006) and 10.2 μg/l (2008) for 5cx-MEPP, 7.2 (2002), 6.5 (2004), 5.1 (2006) and 4.6 μg/l (2008) for 2cx-MMHxP, 3.3 (2002), 2.8 (2004), 3.5 (2006) and 3.6 μg/l (2008) for OH-MiNP, 2.1 (2002), 2.1 (2004), 2.2 (2006) and 2.3 μg/l (2008) for oxo-MiNP and 4.1 (2002), 3.2 (2004), 4.1 (2006) and 3.6 μg/l (2008) for cx-MiNP. The investigation of the time series 1988-2008 indicates a decrease of the internal exposure to DnBP by the factor of 7-8 and to DEHP and BzBP by the factor of 2-3. In contrast, an increase of the internal exposure by the factor of 4 was observed for DiNP over the study period. The exposure to DiBP was found to be stable. In summary, we found decreases of the internal human exposure for legally restricted phthalates whereas the exposure to their substitutes increased. Future investigations should verify these trends. This is of increasing importance since the European Commission decided to require ban or authorization from 1.1.2015 for DEHP, DnBP, DiBP and BzBP according to REACh Annex XIV.

Human volunteer studies investigating the potential for toxicokinetic interactions between the pesticides deltamethrin, pirimicarb and chlorpyrifos-methyl following oral exposure at the Acceptable Daily Intake

ObjectivesTo determine whether there are metabolic interactions between deltamethrin or pirimicarb and chlorpyrifos-methyl in humans at dietary levels. Deltamethrin and pirimicarb are metabolised in-vivo by hydrolytic enzymes, which may be...

Effect of graded levels of niacin supplementation of a semipurified diet on energy and nitrogen balance, growth performance, diarrhea occurrence, and niacin metabolite excretion by growing swine1

Thirty-six crossbred barrows with an average initial age of 42 d and BW of 13.8 kg were placed in individual metabolism crates in a 35-d experiment to evaluate the supplementation of a semipurified diet with graded levels of crystalline niacin. Response criteria were energy and N balance, growth performance, occurrence of niacin deficiency diarrhea, and urinary excretion of the niacin metabolite N(1)-methyl-2-pyridone-5-carboxylamide (PYR). The basal diet met the true ileal Trp requirement of growing swine, and supplementation with 6, 10, 14, 18, 22, or 44 mg of niacin/kg made 6 treatments. Pigs were observed for scours twice daily, and pig BW and feed consumption were determined weekly. Total urine collections and fecal grab samples were made twice daily from each pig from d 28 to 35. Pigs fed the diet containing 14 mg of niacin/kg absorbed and retained more (P < 0.05) grams of N/d, had a greater N digestibility (%, P < 0.05), a greater ADFI and ADG (P < 0.10), and no diarrhea (P < 0.05) compared with pigs fed the diet containing 6 mg of niacin/kg, and pigs fed the diet containing 10 mg of niacin/kg were intermediate in ADG. There were no additional improvements in the response criteria with niacin supplementation greater than 14 mg/kg. Urinary PYR criteria (mg/L and mg/d) were greater (P < 0.001) for pigs fed the diet containing 44 mg of niacin/kg than for pigs fed the diets containing 6 to 22 mg of niacin/kg. However, urinary PYR criteria for pigs fed the diets containing 6 to 22 mg of niacin/kg did not differ from each other, indicating that PYR was not a sensitive indicator of niacin status for growing swine. Niacin treatment did not affect the percentages of N retained/N absorbed, N retained/N intake, DE, or ME. In conclusion, 14 mg of crystalline niacin/kg of semipurified diet adequate in Trp was the minimum concentration of niacin that maximized N utilization and growth performance, and prevented niacin deficiency diarrhea of growing swine in the current experiment. Because practical feed ingredients may be sources of available endogenous niacin, supplementation of practical diets with 100% of the current NRC requirement for niacin should provide adequate niacin for growing swine.

Valproic acid utilizes the isoleucine breakdown pathway for its complete β-oxidation

Valproic acid (VPA) is a simple branched medium-chain fatty acid with expanding therapeutic applications beyond its prime anticonvulsant properties. Aims (1) To resolve the underlying basis for the interference of valproate with the isoleucine degradative pathway and (2) to shed new light on the enzymology of the β-oxidation pathway of valproate. Methods Urine organic acids were analyzed by gas chromatography/mass spectrometry. In vitro studies were performed with heterologously expressed human 2-methyl-3-hydroxybutyryl-CoA dehydrogenase (MHBD) and fibroblasts from controls and a patient with MHBD deficiency using 2-methyl-3-hydroxybutyryl-CoA and 3-hydroxyvalproyl-CoA as substrates. The respective enzymatic activities were measured using optimized HPLC procedures. Short-chain enoyl-CoA hydratase (ECHS1) immunoprecipitation in a human liver homogenate was performed and hydratase activity was measured in the supernatants by HPLC, using crotonyl-CoA and Δ 2(E)-valproyl-CoA as substrates. Results Patients on valproate therapy had a moderately increased urinary excretion of the isoleucine metabolite 2-methyl-3-hydroxybutyric acid. MHBD was found to convert 3-hydroxyvalproyl-CoA into 3-ketovalproyl-CoA. MHBD activity in control fibroblasts was comparable using both 2-methyl-3-hydroxybutyryl-CoA and 3-hydroxyvalproyl-CoA as substrates. In fibroblasts of a patient with MHBD deficiency, there was no detectable MHBD activity when 3-hydroxyvalproyl-CoA was used as substrate. Samples with immunoprecipitated crotonase had no detectable hydratase activity using both crotonyl-CoA and Δ 2(E)-valproyl-CoA as substrates. Discussion This work demonstrates for the first time, that MHBD is the unique enzyme responsible for the dehydrogenation of 3-hydroxyvalproyl-CoA. Furthermore, we show that crotonase is the major, if not the single hydratase involved in VPA β-oxidation, next to its role in isoleucine catabolism.

Effect of Simultaneous Consumption of Milk and Coffee on Chlorogenic Acids’ Bioavailability in Humans

Different studies have shown that milk may interact with polyphenols and affect their bioavailability in humans. The present study investigated the effect of the simultaneous consumption of coffee and milk on the urinary excretion of chlorogenic acids (CGA) and metabolites. Subjects were submitted to consumption of water, instant coffee (609 mmol of CGA) dissolved in water, and instant coffee dissolved in whole milk. Urine was collected for 24 h after consumption of each treatment for analysis of CGA and metabolites by HPLC/LC-MS. The amount of CGA and metabolites recovered after consumption of combined coffee-milk (40% ± 27%) was consistently lower in all subjects compared to that of coffee alone (68% ± 20%). Concluding, the simultaneous consumption of milk and coffee may impair the bioavailability of coffee CGA in humans.

Metabolism and Disposition of Isoflavone Conjugated Metabolites in Humans after Ingestion of Kinako

Isoflavone aglycones daidzein (Dein) and genistein (Gein) are present primarily as glucuronides and sulfates in human plasma; however, very little is known about the plasma pharmacokinetics of isoflavone conjugates after soy ingestion. The aim of this study was to investigate metabolism and disposition of the isoflavone conjugated metabolites glucuronide or sulfate or both after ingestion of kinako (baked soybean flour) by 10 volunteers. The quantifications of 16 metabolites in plasma and urine were performed by our previously reported high-performance liquid chromatography-UV-diode-array detector method. Plasma concentrations of total Dein and Gein metabolites reached maximal values of 0.64 ± 0.18 μM at 4.7 ± 2.5 h and 1.58 ± 0.55 μM at 5.4 ± 2.1 h, respectively. The area under the curve from 0 to 48 h demonstrated that daidzein-7-glucuronide-4'-sulfate (D-7G-4'S) (53.3%) was a major metabolite of Dein and that genistein-7-glucuronide-4'-sulfate (G-7G-4'S) (54.0%) and genistein-4',7-diglucuronide (G-4',7-diG) (26.6%) were major metabolites of Gein in plasma. The compositions of isoflavone metabolites in urine and plasma were greatly different. Approximately half of the 48-h urinary excretion of total Dein metabolites consisted of daidzein-7-glucuronide. The total amounts of genistein-7-glucuronide and genistein-4'-glucuronide were half the total amount of the urinary Gein metabolites. Excretion into urine of D-7G-4'S and G-7G-4'S accounted for only 16% each of the total Dein and Gein metabolites, respectively. The plasma and urine profiles of 16 metabolites of Dein and Gein demonstrate the involvement of desulfation and deglucuronidation of the conjugated metabolites D-7G-4'S, G-7G-4'S, and G-4',7-diG in the process of renal excretion.

A twenty-volunteer study using deuterium labelling to determine the kinetics and fractional excretion of primary and secondary urinary metabolites of di-2-ethylhexylphthalate and di-iso-nonylphthalate

This study has obtained estimates of the kinetics and fractional excretion factors of metabolism of DEHP and DINP to their main primary and secondary metabolites. Samples were obtained from an open-label, fixed sequence, single oral dose study in 10 male and 10 female subjects. The dosed substances were deuterated di-2-ethylhexylphthalate (D4-DEHP) and di-isononylphthalate (D4-DINP) at two dose levels. Urine samples were collected at intervals up to 48h post-dose. LC–MS/MS was used to measure metabolite concentrations. Excreted amounts were then calculated using urine volumes. Metabolite half-lives were estimated to be 4–8h with more than 90% of metabolites in the first 24h of urine collections and the remainder in the 24–48h period. The four metabolites of DEHP amounted to 47.1±8.5% fractional excretion on a molar basis. For DINP the identified metabolites totalled 32.9±6.4%. For both DEHP and DINP the metabolites were in the abundance order -monoester<-oxo<-carboxy<-hydroxy. These robust fractional excretion values for the main primary and secondary phthalate metabolites along with estimates of their uncertainty can be used in future surveys of human exposure to DEHP and DINP.

Regular consumption of cocoa powder with milk increases HDL cholesterol and reduces oxidized LDL levels in subjects at high-risk of cardiovascular disease

Background and AimsEpidemiological studies suggest that regular consumption of cocoa-containing products may confer cardiovascular protection, reducing the risk of coronary heart disease (CHD). However, studies on the effects of cocoa on different cardiovascular risk factors are still scarce.The aim of this study was too evaluate the effects of chronic cocoa consumption on lipid profile, oxidized low-density lipoprotein (oxLDL) particles and plasma antioxidant vitamin concentrations in high-risk patients. Methods and ResultsForty-two high-risk volunteers (19 men and 23 women, mean age 69.7 ± 11.5 years) were included in a randomized, crossover feeding trial. All received 40g of cocoa powder with 500 mL of skimmed milk/day(C + M) or only 500 mL/day of skimmed milk (M) for 4 weeks in a random order. Before and after each intervention period, plasma lipids, oxLDL and antioxidant vitamin concentrations were measured, as well as urinary cocoa polyphenols metabolites derived from phase II and microbial metabolisms. Compared to M, C + M intervention increases HDLc [2.67 mg/dL (95% confidence intervals, CI, 0.58–4.73; P = 0.008)] and decreases oxLDL levels [−12.3 U/L (CI,−19.3 to −5.2;P = 0.001)]. No changes between intervention groups were observed in vitamins B1, B6, B12, C and E, or folic acid concentrations. In addition, subjects who showed higher increments in urinary cocoa polyphenol metabolites exhibited significant increases in HDLc and significant decreases in oxLDL levels (P < 0.05; all). ConclusionsConsumption of cocoa power with milk modulates the lipid profile in high-risk subjects for CHD. In addition, the relationship observed between the urinary excretion of cocoa polyphenol metabolites and plasma HDLc and oxLDL levels suggests a beneficial role for cocoa polyphenols in lipid metabolism.

Abstract 5465: Modulation of DMS612 (BEN) pharmacokinetics and metabolism in mice by disulfiram, and aldehyde dehydrogenase inhibitor

Abstract Introduction: DMS612 (NSC 281612, BEN) is an alkylating agent in clinical trials based on its in vitro and in vivo activity against renal cell carcinoma. We previously reported that BEN is rapidly metabolized into its carboxylic acid (BA), and that BEN and BA undergo chemical degradation both in vitro and in vivo. In addition, we demonstrated that BEN is rapidly metabolized into at least 13 different analytes in vivo. We hypothesized that BEN is metabolized to BA by aldehyde dehydrogenase (ALDH). In an attempt to increase the exposure to BEN, we explored the effect of the ALDH inhibitor disulfiram on the pharmacokinetics of BEN in mice. Materials &amp; Methods: Female CD2F1 mice were dosed with either 20 mg/kg BEN i.v. alone or 24 h after the i.p. administration of 300 mg/kg disulfiram. Plasma and urine concentrations of BEN and its metabolites were quantitated by LC-MS/MS. Plasma pharmacokinetic parameters were calculated non-compartmentally. Urinary excretion of BEN and metabolites was calculated as percentage of the dose. Results: BEN was metabolized to at least 13 different products as previously reported. In the BEN alone study, BEN was metabolized quickly with a half-life &amp;lt;5 min. The half-lives of the metabolites were &amp;lt; 2 h. Pretreatment with disulfiram resulted in a 300-fold increase in exposure to BEN, from AUC0-inf 143 ng/mL*min to 40,515 ng/mL*min, while BA exposure remained similar, at AUC0-inf 254,280 ng/mL*min after BEN alone to AUC0-inf 274,947 ng/mL*min after disulfiram. In addition, the half-lives and AUCs of some of the metabolites in the BEN + disulfiram study appeared to be longer than when BEN was administered alone. Urinary excretion of BEN was increased 50% after disulfiram (from 1% to 1.5 % of the dose), BA excretion accounted for 5.8% of the dose after BEN alone and this was not markedly affected by disulfiram pretreatment. Conclusions: BEN is rapidly metabolized into many metabolites, which could affect the efficacy of BEN as an anti-neoplastic agent. We have demonstrated that by administering the ALDH inhibitor disulfiram the exposure to BEN is greatly increased, suggesting that ALDH is at least partly responsible for the rapid metabolism of BEN. However, the plasma exposure to BA increased only 8%. Our results will aid in the interpretation of ongoing clinical studies with BEN, which include genotyping for ALDH. Support: N01-CM07106, N01-CM52202, P30-CA47904. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 5465. doi:10.1158/1538-7445.AM2011-5465

The urinary excretion of tryptophan and tryptophan metabolites in the chronic ethanol-fed rat.

An investigation was made into the hypothesis that chronic ethanol ingestion disturbs the metabolism of tryptophan which is reflected by alterations in the urinary excretion of the metabolites 5-hydroxyindoleacetic acid (5-HIAA), anthranilic acid (AA) and indoleacetic acid (IAA). In particular, we investigated whether experimental chronic alcoholism is associated with a decrease in the tryptophan metabolite ratios as suggested in the literature. Male Wistar rats were chronically fed a nutritionally-complete liquid diet in which ethanol comprised 35% of total calories: controls were pair-fed identical amounts of the same diet in which ethanol was replaced by isocaloric glucose. At 6 weeks, 24 h urine samples were collected for the analysis of tryptophan, 5-HIAA, AA and IAA by HPLC. During ethanol-feeding there were reductions in the daily urinary excretion (i.e. mumol/24 h) of tryptophan (-57%, P = 0.026) and concomitant increases in 5-HIAA excretion (62%, P = 0.057). Expression of data in terms of lean tissue mass (i.e. urinary creatinine) revealed identical conclusions. An analysis was performed on the molar ratios of these urinary analytes. The tryptophan: total metabolite ratio was significantly decreased (by -53%), but the AA: total metabolite ratio was not significantly altered (P = 0.102). The ratios 5-HIAA/AA and 5-HIAA/IAA were slightly increased, but they did not attain statistical significance (P > 0.351). It was concluded that chronic ethanol feeding is associated with significant changes in the urinary excretion of tryptophan and its related metabolites.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of phenobarbitone pretreatment on disposition of amidopyrine and its metabolites in rat.

Plasma concentration-time profiles for amidopyrine and its primary desmethyl metabolite have been determined in control rats and in rats pretreated with phenobarbitone. The kinetics of both compounds indicate enhanced clearance following pretreatment. Metabolite excretion in urine, bile and breath support the plasma data. It would appear that pheno barbitone pretreatment results in quantitative but not qualitative changes in the metabolism of amidopyrine in rat.

Further study on the correlation of urinary excretion of a methadone metabolite with methadone metabolism and analgesia in the rat.

Further study on the correlation of urinary excretion of a methadone metabolite with methadone metabolism and analgesia in the rat.