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J Chromatogr B Analyt Technol Biomed Life Sci. 2005 Nov 5;826 (1-2):238-43 16183337 (P,S,G,E,B,D)
Department of Biopharmaceutics, School of Pharmaceutical Sciences, Central South University, Changsha, Hunan 410013, PR China.
This study describes an high-performance liquid chromatographic (HPLC)-UV method for the simultaneous determination of 6beta-hydroxycortisol (6beta-OHF) and cortisol (F) in human urine and plasma. The within-day relative standard deviation of the three concentrations for both analytes was less than 6.2%. Accuracy determined at three concentrations ranged between 95 and 107%. The extraction recoveries were 64.1+/-4.3 and 88.1+/-2.4% at three concentrations for 6beta-OHF and F in urine, respectively. The extraction recoveries were 88.7+/-1.4% at three concentrations for F in plasma. This is the first HPLC method that can simultaneously determine 6beta-OHF and F in human urine and plasma and is suitable for routine assessment of the CYP3A activity expressed as 6beta-hydroxylation clearance.

Other papers by authors:

Zhong Nan Da Xue Xue Bao Yi Xue Ban. 2007 Oct ;32 (5):855-861 18007084 (P,S,G,E,B)
Objective To determine the pharmacokinetic interaction between cefalor and bromhexine in healthy Chinese volunteers. Methods Twelve subjects received a cefaclor (CEF) treatment, a bromhexine (BHX) treatment, and a co-treatment of CEF and BHX with a 3*3 Latin square design. The wash-out time between periods was 14 days. The plasma and urine drug concentrations of CEF and BHX were detected by HPLC-UV and LC/MS, respectively. Results All the 12 volunteers completed the study. There were no significant differences in AUC(0-t) and C(max) of CEF in logarithm between the single administration group of CEF and the co-administration group of CEF with BHX. Two one sided t-test showed that CEF was bioequivalent in the 2 groups. There were no significant differences in t(max), MRT, t(1/2), and Clr between the 2 groups. V(d)/F was significantly lower in the single CEF group than in the co-administration group of CEF and BHX. There were no significant differences of AUC(0-t) and C(max) of BHX in logarithm between the single administration group of BHX and the co-administration group of BHX with CEF. Two one sided t-test showed that BHX was bioequivalent in the 2 groups. There were no significant differences in t(max), MRT, t(1/2), V(d)/F, and Clr between the 2 groups. Conclusion There is no significant pharmacokinetic parameter change in the drug absorption, metabolism, and excretion, but V(d)/F of CEF significant increases in the co-administration of CEF with BHX. The co-administration of CEF and BHX has no adverse drug interaction. The increase of V(d)/F may be a favorable drug interaction, which may be the mechanism of the synergistic effect of the 2 drugs.
Zhong Nan Da Xue Xue Bao Yi Xue Ban. 2006 Dec ;31 (6):858-61 17213583 (P,S,G,E,B)
School of Pharmaceutical Sciences, Central South University, Changsha 410013, China.
OBJECTIVE: To explore the inhibitive effects of 1,3,8-trihydroxy-5-methoxyxanthone (TMX) on cytochrome P450s (CYP450s) in human liver microsomes. METHODS: Probe drugs were incubated with and without adding TMX to determine the changes of enzyme activities. The concentration ratio of metabolites to probe drugs was used to present enzyme activities. Concentrations of the probe drugs and their metabolites in the incubated mixture were detected by high performance liquid chromatography. RESULTS: The variations (mean, 95%CI) of the activities of CYP1A2, CYP2C9, CYP2C19, CYP2E1 and CYP3A4 were 2.95 x 10(-3)(2.03 x 10(-3), 3.88 x 10(-3)), 3.14 x 10(-2)(1.87 x 10(-2), 4.42 x 10(-2)), 2.27 x 10(-3)(-1.4 x 10(-2),1.81 x 10(-2)), 7.72 x 10(-2)(-0.83 x 10(-2), 0.2374), and -0.2548 (-2.9802, 2.4707), respectively. The activities of CYP1A2 and CYP2C9 were significantly reduced in the present of TMX. CONCLUSION: TMX (10 micromol/L) has significant inhibitive effect on the activities of CYP1A2 and CYP2C9, but no significant inhibitive effect on the activities of CYP2C19, CYP2E1 and CYP3A4.
J Chromatogr B Analyt Technol Biomed Life Sci. 2006 Mar 9;: 16530492 (P,S,G,E,B,D)
Department of Biopharmaceutics, School of Pharmaceutical Sciences, Central South University, Changsha 410013, PR China.
An HPLC-UV method was developed and validated for the determination of AKF-PD in whole blood of rat. Phenacetin was chosen as the internal standard, and the separation was achieved on a C(18) column with methanol and 0.02M phosphate buffer (pH 3.2) as mobile phase. The obtained calibration graphs were linear (r=0.9999, n=9) in the range of 0.203-52.0mugml(-1). The low limit of quantitation was 0.203mugml(-1). This method can be used to study the pharmacokinetics of AKF-PD in rat.
Clin Pharmacol Ther. 2005 Sep ;78 (3):249-59 16153396 (P,S,G,E,B,D) Cited:12
Department of Genomics and Proteomics, Beijing Institute of Radiation Medicine, Beijing, China.
OBJECTIVE: This study was designed to better understand genetic variation in the cytochrome P450 (CYP) gene CYP1A2 and its impact on CYP1A2 activity in Chinese subjects. METHODS: CYP1A2 genetic polymorphisms were screened by direct sequencing in 27 selected Chinese subjects. Plasma 1,7-dimethylxanthine/caffeine ratios 5 hours after a 100-mg caffeine administration, used as an index of CYP1A2 in vivo activity, were determined in 422 healthy subjects. Five single-nucleotide polymorphism markers, including G-860A (CYP1A2*1C), T-3594G, G-3113A, A-163C (CYP1A2*1F), and C5347T (CYP1A2*1B), were selected and genotyped by either polymerase chain reaction-restriction fragment length polymorphism or direct sequencing. RESULTS: Thirteen polymorphisms and 2 linkage disequilibrium blocks with a boundary around -2467 were identified at this locus. The allele frequency for -3860A,-3594G,-3113A,-163C, and 5347T was 0.21, 0.15, 0.10, 0.36, and 0.14, respectively, in the CYP1A2-phenotyped cohort. A significant difference in CYP1A2 activity was observed among genotypes of polymorphism G-3113A (P =.038), and CYP1A2 activity in subjects carrying the AA genotype was lower than that in those carrying the GA (P =.096) and GG genotypes (P =.036):-0.45 +/- 0.05 (mean +/- SD),-0.32 +/- 0.16, and -0.29 +/- 0.16, respectively. Further analysis based on haplotype pairs found a 1.92-fold variation (95% confidence interval, 1.13-2.71) in mean CYP1A2 activity between haplotype pairs 13 and 15, and the difference was significant (-0.19 +/- 0.15 versus -0.45 +/- 0.05, P =.016). As compared with haplotype pair 10, haplotype pairs 9 and 15 and most haplotype pairs heterozygous for the haplotype with an A allele at -3113, including pairs 5, 8, and 12, also showed significantly lower CYP1A2 activity (P =.015,.048,.008,.024, and .014 for pairs 5, 8, 9, 12, and 15, respectively). In addition, haplotype pairs 5, 9, and 12 also showed significantly lower CYP1A2 activity than pair 13 (P =.034,.020, and .037 for pairs 5, 9, and 12, respectively). CONCLUSIONS: The G-3113A polymorphism is associated with decreased CYP1A2 activity, haplotype pairs 10 and 13 are responsible for high CYP1A2 activity, and haplotype pairs 5, 8, 9, 12, and 15 are responsible for low CYP1A2 activity in Chinese subjects.
Histochem Cell Biol. 2010 Jan 10;: 20063008 (P,S,G,E,B,D)
Institute of Health Sciences, Shanghai Jiao Tong University School of Medicine, 200025, Shanghai, China, wufenglan210@hotmail.com.
To determine the possible involvement of neutrophils in the pathogenesis of experimental autoimmune encephalomyelitis (EAE), we examined their infiltration pattern during the course of MOG(35-55)-induced EAE in the C57BL/6 mice. Using immunohistochemistry and flow cytometry, we found that the number of neutrophils was significantly increased during onset of disease, remained high at the peak stage and dramatically declined thereafter. Moreover, dual labeling provided anatomical evidence of a prominent accumulation of neutrophils in the center and vicinity of lesion areas of demyelination, axonal loss or axonal degeneration at early stages of EAE. These observations provide evidence that neutrophils are one of the major sources of inflammatory cells to initiate EAE, which suggest that neutrophils may contribute to demyelination and axonal degeneration in the acute phase of EAE and play a greater role than previously thought in the pathogenesis of EAE.
Virology. 2010 Jan 9;: 20060995 (P,S,G,E,B,D)
Department of Epidemiology, School of Public Health, The Fourth Military Medical University, No.17, Changle west RD, Xi'an 710032, China.
The development of effective vaccines and antiviral prophylaxis against human enterovirus 71 (EV71) has been hampered by the extensive antigenic diversity of the virus. To gain new insights into the evolutionary processes that create this genetic diversity, the TreeOrder Scan Method and RDP program were employed to detect recombination events in the genome, and then parsimony-based and maximum-likelihood-based methods were used to detect natural selection effects on viral proteins. Recombination analysis provided strong evidence for recombination events in the majority of the sequences analyzed. Recombination events were found to be distributed nonrandomly with the highest frequency at the 3D region. Furthermore, positive selection was only detected at site 145 of VP1 by the maximum likelihood-based method. These results reveal that EV71 proteins are extensively influenced by stabilizing selection. We conclude that recombination may play a more important role than positive selection in the formation of genetic diversity.
Int J Biol Macromol. 2009 Nov 23;: 19941888 (P,S,G,E,B,D)
Department of Pharmacology, School of Pharmacy, the Fourth Military Medical University, Xi'an, Shaanxi 710032, China.
In this study, three acidic polysaccharides (APS-3a, APS-3b and APS-3c) were obtained from Angelica sinensis(Oliv.) Diels. They displayed different structural features and anti-tumor activities. APS-3b and APS-3c significantly inhibited the growth of S180 tumors and increased the life spans of S180 tumor-bearing mice, whereas APS-3a had no significant effect. The further experiments showed that APS-3b and APS-3c could cause a concentration-dependent proliferation of the splenocytes, up-regulate IFN-gamma, IL-2 and IL-6 mRNA expression in splenocytes and stimulate the productions of NO and TNF-alpha in peritoneal macrophages. Taken together, the three acidic polysaccharides displayed different anti-tumor activities which were associated with their different structural characteristics.
J Gen Appl Microbiol. 2009 ;55 (5):381-393 19940384 (P,S,G,E,B)
Department of Biotechnology, Graduate School of Agricultural and Life Sciences, The University of Tokyo.
Computational approaches provide valuable information to start experimental surveys identifying glycosylphosphatidylinositol (GPI)-anchored proteins in protein sequence databases. We developed a new sequence-based identification system that uses an optimized classifier based on a support vector machine (SVM) algorithm to recognize appropriate COOH-terminal sequences and uses a classifier implementing a simple majority voting strategy to recognize appropriate NH(2)-terminal sequences. The SVM classifier showed high accuracy (96%) in 5-fold cross-validation testing, and the majority voting classifier showed high recall (98.88%) when applied to a test dataset of eukaryote proteins. When applied to S. cerevisiae protein sequences, the new identification system showed good ability to classify "unseen" data. Applying our system to protein sequences of three aspergilli, we identified 115 GPI-anchored proteins in Aspergillus fumigatus, 129 in Aspergillus nidulans, and 136 in Aspergillus oryzae. Sequence-based conserved domain search found nearly half of these proteins to have conserved domains that covered a wide range of functions.
Nan Fang Yi Ke Da Xue Xue Bao. 2009 Nov ;29 (11):2291-4 19923090 (P,S,G,E,B)
Laboratory Animal Center, Xi'an Jiaotong University College of Medicine, Xi'an 710061, China.E-mail: linyan506@163.com.
OBJECTIVE: To establish a convenient method for preparing rabbit models of ischemic cerebral infarction using autologous clot embolism. METHODS: Ischemic cerebral infarction was induced in rabbits by embolizing the middle cerebral artery using autologous clot emboli. Clinical and histological observations were carried out to evaluate the validity of the animal model. RESULTS: Hemiplegia of different severities was observed in the rabbits after the operation. TTC and HE staining of the brain sections confirmed ischemic cerebral infarction 6 h after obstructing the middle cerebral artery with the autologous clot emboli. CONCLUSION: Embolizing the middle cerebral artery using the autologous emboli is convenient to induce focal ischemic cerebral infarction in rabbits. This model has practical value in the study on the mechanism of ischemic cerebrovascular disease and in developing new strategies for prevention and treatment of the relevant diseases in human.
Neurosci Lett. 2009 Nov 13;: 19922770 (P,S,G,E,B,D)
Forensic Department, Xi'an Jiaotong University School of Medicine, 76# West Yanta Road, Xi'an 710061, P.R. China; The Key Laboratory of Health Ministry for Forensic Sciences, 76# West Yanta Road, Xi'an 710061, P.R. China.
Mitogen-activated protein kinases (MAPK) can be activated by opioids such as morphine via opioid receptor, and their activations have been observed in synaptic plasticity, learning, memory and addiction. Long-term exposure to morphine may induce physical dependence, manifested as somatic withdrawal symptoms such as diarrhea, body weight loss, jumping and headshaking, when drug is deprived. Though morphine dependence and withdrawal have been extensively studied, their molecular mechanisms have not been fully elucidated. In the present study, the physical dependence on morphine was developed in mice by an intermittent, escalating procedure of morphine injections, and was measured by the body weight loss and the behavioral signs (jumping and headshaking). We found that the mice with chronic morphine administration experienced dramatic body weight loss, compared with the saline-treated controls. Naloxone-precipitated withdrawal led to more body weight loss, compared with spontaneous withdrawal. Naloxone-precipitated withdrawal mice showed significantly aggravated morphine-withdrawal symptoms (including jumping and heading shaking), compared with spontaneous withdrawal mice. MAPK pathway activities in the frontal association cortex (FrA), accumbens nucleus (Acb) and caudate putamen (CPu) were examined to probe into molecular mechanism for morphine dependence and withdrawal. Compared with saline-treated mice,morphine-dependent mice and spontaneous withdrawal mice, naloxone-precipitated withdrawal mice showed a significantly increased ERK phosphorylation in FrA and Acb, but not in CPu. However, the activities of other protein kinases in the MAPK pathway, including p38 and JNK, showed no changes in FrA, Acb and CPu of the mice during the chronic morphine dependence and withdrawal phases. These results suggest that the ERK phosphorylation in FrA and Acb may be associated with naloxone-precipitated withdrawal syndrome.

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J Chromatogr B Analyt Technol Biomed Life Sci. 2009 Dec 1;: 19959402 (P,S,G,E,B,D)
Department of Toxicology, University of Würzburg, 9 Versbacher St., D-97078 Würzburg, Germany.
Drug-drug and food-drug interactions are often due to an inhibition or induction of drug-metabolizing cytochrome P450 (CYP) enzymes and may result in non-response or adverse reactions. Hence, phenotypic biomarkers of CYP activity appear as useful tools for individualized pharmacotherapy. The metabolic ratio (MR) of the concentration of 6beta-hydroxycortisol (6beta-OHC) to cortisol (MR 6beta-OHC/cortisol) in human urine had been proposed as an endogenous marker for CYP3A activity. Here, we report on the improvement of published LC-MS/MS methods for the simultaneous quantification of cortisol and 6beta-OHC, using on-line sample cleanup by column switching and isotope-labeled analogues as internal standards.[(2)H(2)]6beta-OHC was prepared by incubation of human recombinant CYP3A4 with commercially available [(2)H(2)]cortisol. Analytical sensitivity could be increased about 10-fold. The first morning urine of 69 female and 27 male healthy volunteers was analyzed for cortisol and 6beta-OHC. Concentrations ranged from 1.0 to 142 and 24 to 670ng/mL, respectively. Individual MR 6beta-OHC/cortisol varied more than 20-fold and we were able to show for the first time for a Caucasian population significantly higher MR values in females as compared to males. This non-invasive biomarker for CYP3A activity lends itself for the study of genetic differences as well as enzyme induction or inhibition in the clinical setting without the need of using a probe drug.
Acta Pharmacol Sin. 2009 Aug 24;: 19701237 (P,S,G,E,B,D)
Research Institute of Drug Metabolism and Pharmacokinetics, School of Pharmaceutical Sciences, Central South University, Changsha 410013, China.
AbstractAim:Currently, there is considerable debate as to which method is more accurate for measuring the activity of CYP3A in vivo: cortisol 6beta-hydroxylation clearance (Cl(m(6beta))) or the urinary ratio of 6beta-OHF to F (6beta-OHF/F). Furthermore, the value of measuring endogenous levels of cortisol over a 24 h period (AUC(F)) needs to be confirmed. The aim of the present study was to determine which method was most effective at measuring changes in the in vivo activity of CYP3A: AUC(F), Cl(m(6beta)), or 6beta-OHF/F.Methods:A two phase, cross-over design was adopted in this study. A total of 24 subjects (12 males and 12 females) were randomly assigned to one of two groups: the test group subjects were given 250 mg clarithromycin tablets twice a day for a period of 4 d, whereas the control group received a placebo twice daily for a similar period. On d 5 of the study, the last dose of either clarithromycin or placebo was supplemented with an oral dose of 7.5 mg midazolam (MDZ); blood and urine samples were then collected at various times. All samples collected at the same sampling times on d 4 were used to evaluate the effects of MDZ administration on cortisol levels and metabolism. The ratio of 1-hydroxymidazolam (1-OHMDZ) concentration to MDZ concentration at 1 h (MR) was taken as a measure of the in vivo CYP3A activity. AUC(F), Cl(m(6beta)), and 6beta-OHF/F were also used as biomarkers for CYP3A activity.Results:No correlations were found (either before or after inhibition) between CYP3A activity and any of the following measures: AUC(F), Cl(m(6beta)), or 6beta-OHF/F (r<0.4, P>0.05). After 4 d of clarithromycin administration, CYP3A activity (MR) decreased by 75%(P=0.000), whereas AUC(F) increased by 19%(P=0.040), and Cl(m(6beta)) and 6beta-OHF/F decreased by 54.2%(P=0.000) and 50%(P=0.003), respectively. No significant changes in AUC(F)(P=0.178), or in the amount of urinary 6beta-OHF (P=0.169), or in F (P=0.391) were found over a 24 h time period, either with or without MDZ administration.Conclusion:Although Cl(m(6beta)) and 6beta-OHF/F can reflect the decline in CYP3A activity, the impression they provide is neither accurate nor complete. AUC(F) is completely ineffective for evaluating variations in CYP3A activity. MDZ administration had no evident effects on either cortisol metabolism or excretion over a period of 24 h.Acta Pharmacologica Sinica advance online publication, 24 August 2009; doi: 10.1038/aps.2009.116.
Anal Chim Acta. 2007 Mar 14;586 (1-2):228-232 17386716 (P,S,G,E,B,D) Cited:1
Dipartimento di Sanità pubblica Patologia comparata e Igiene veterinaria, Facoltà di Medicina Veterinaria, Università di Padova, Viale dell’Università 16, 35020 Legnaro, Padova, Italy.
Dexamethasone (DXM) is often illegally used as a growth promoter. To identify indirect biomarkers of illicit treatments, the urinary ratio between 6beta-hydroxycortisol (6beta-OHF) and cortisol (F) was measured in urines obtained from bulls experimentally treated per os and intramuscularly (im) with different DXM dosages. Dexamethasone, given per os at low doses elicited an early and lasting significant reduction of 6beta-OHF/F. No significant variations were seen in urines from bulls given DXM intramuscularly. These results suggest 6beta-OHF/F as a rapid, non-invasive, screening test for oral, low-dose, long-term corticosteroid treatment in cattle. Further studies are required to go deep inside the biochemical and molecular events underlying such an effect.
Br J Clin Pharmacol. 2006 Nov 10;: 17094779 (P,S,G,E,B,D)
Martin Fenske
Department of Animal Physiology, University of Bayreuth, Bayreuth, Germany.
Br J Clin Pharmacol. 2006 Nov 10;: 17094778 (P,S,G,E,B,D)
Daiichi Asubio Pharmaceuticals Inc, Rochelle Park, NJ.
Br J Clin Pharmacol. 2006 Aug ;62 (2):187-95 16842393 (P,S,G,E,B)
University of North Carolina, School of Pharmacy, Chapel Hill, NC 27599, USA.
AIMS: A non-invasive proposed method for measuring CYP3A activity is the urinary 6beta-hydroxycortisol:cortisol ratio. This ratio has been used as an indicator of CYP3A induction and inhibition, with mixed results. This investigation evaluated the relationship between a validated, biomarker, intravenous midazolam clearance and the urinary cortisol ratio under constitutive conditions and with the influence of a moderate CYP3A inhibitor. METHODS: This was a sequential, cross-over study design. Intravenous midazolam 0.025 mg kg(-1) was administered to 10 male and 10 female subjects once every 14 days for 4 months. Fluvoxamine 150 mg day(-1) was given to all subjects during the last two visits. Total body clearance of midazolam and urinary 6beta-hydroxycortisol:cortisol molar ratio were used as biomarkers of hepatic CYP3A activity. RESULTS: No significant correlations were found between these two markers (r(2)< 0.5, P > 0.05). Larger interindividual and intra-individual variability in CYP3A activity was observed in 6beta-hydroxycortisol:cortisol ratios compared with midazolam clearances. With fluvoxamine therapy, midazolam clearance values decreased approximately 1.5-fold and cortisol ratios decreased approximately 1.9-fold. CONCLUSIONS: The high intra-individual variability of the urinary cortisol ratio, compared with midazolam, makes this a suboptimal CYP3A phenotyping tool.
Physiol Res. 2006 Jun 22;: 16792464 (P,S,G,E,B)
Department of Pharmacology, Charles University in Prague, Faculty of Medicine in Hradec Kralove, PO Box 38, Simkova 870, 500 38 Hradec Kralove, Czech Republic; micuda@lfhk.cuni.cz.
The 24-hour urinary excretion of 6-beta-hydroxycortisol (6beta-OHC) and the urinary ratio of 6beta-hydroxycortisol/cortisol (6beta-OHC/UFC) have been proposed as noninvasive probes for human cytochrome P450 3A4 isoform (CYP3A4). In this study, we evaluated within- and between-day variability of 6beta-OHC excretion and 6beta-OHC/UFC ratio in nine Caucasian men with cardiac disease. Each study participant was asked to collect 24-hour urine specimens during four consecutive days in five standardized time intervals. Concentrations of UFC and 6beta-OHC were determined by immunoassay and high-performance liquid chromatographic (HPLC) method, respectively. The HPLC method was accurate and precise, as indicated by a recovery rate of 96.5-103.3% and less than 5.2% and 6.3% of coefficient of variation for within-run and between-run assay, respectively. In patients, diurnal variations in UFC and 6beta-OHC excretion were parallel. Consequently, 6 beta-OHC/UFC ratio remained stable during the day. Both, 6 beta-OHC excretion and 6 beta-OHC/UFC ratio showed significant relationship between 24-hour value and values measured in respective collection periods with best correlations obtained from night interval (22.00-06.00, r = 0.86-0.91). These results indicated that urinary 6 beta-OHC excretion and 6 beta-OHC/UFC ratio measured in overnight/morning urine could precisely reflect 24-hour values even in severely ill patients. In addition, a simple and sensitive HPLC method was described for determination of 6 beta-OHC in urine.
Br J Clin Pharmacol. 2006 May 2;: 16771823 (P,S,G,E,B)
University of North Carolina, School of Pharmacy, Chapel Hill, NC, USA.
Aims A non-invasive proposed method for measuring CYP3A activity is the urinary 6beta-hydroxycortisol:cortisol ratio. This ratio has been used as an indicator of CYP3A induction and inhibition, with mixed results. This investigation evaluated the relationship between a validated, biomarker, intravenous midazolam clearance and the urinary cortisol ratio under constitutive conditions and with the influence of a moderate CYP3A inhibitor. Methods This was a sequential, cross-over study design. Intravenous midazolam 0.025 mg kg(-1) was administered to 10 male and 10 female subjects once every 14 days for 4 months. Fluvoxamine 150 mg day(-1) was given to all subjects during the last two visits. Total body clearance of midazolam and urinary 6beta-hydroxycortisol:cortisol molar ratio were used as biomarkers of hepatic CYP3A activity. Results No significant correlations were found between these two markers (r(2)< 0.5, P > 0.05). Larger interindividual and intra-individual variability in CYP3A activity was observed in 6beta-hydroxycortisol:cortisol ratios compared with midazolam clearances. With fluvoxamine therapy, midazolam clearance values decreased approximately 1.5-fold and cortisol ratios decreased approximately 1.9-fold. Conclusions The high intra-individual variability of the urinary cortisol ratio, compared with midazolam, makes this a suboptimal CYP3A phenotyping tool.
Eur J Clin Pharmacol. 2006 Jun ;62 (6):417-22 16758258 (P,S,G,E,B)
Department of Biochemistry, Postgraduate Institute of Medical Education and Research, Chandigarh, UT-160 012, India, kris_kohli2003@yahoo.com.
OBJECTIVES: To phenotype 200 healthy North Indians for cytochrome P450 3A (CYP3A) activity by measuring urinary ratio of 6beta-OH-cortisol/cortisol (6beta-OH-CS/CS) and to genotype the subjects demonstrating low and high CYP3A activity for the presence of CYP3A4*1B,*2,*4,*5,*6 and *10 alleles. METHODS: Morning spot urine samples were collected from 200 healthy North Indians. CS and 6beta-OH-CS were extracted and quantified by HPLC. Genotyping was performed by polymerase chain reaction (PCR) followed by restriction fragment length polymorphism (RFLP). RESULTS: Urinary 6beta-OH-CS/CS ratio demonstrated a mean of 52.0 +/- 46 (1.1-290). North Indians demonstrated unimodal distribution with respect to urinary 6beta-OH-CS/CS ratio. On the basis of phenotypes, the subjects were divided into three groups demonstrating low (n=50), intermediate (n=100) and high (n=50) CYP3A activity. These groups demonstrated 6beta-OH-CS/CS ratio of 13.4 +/- 5.2 (1.1-21.0), 40 +/- 11.9 (21.2-63.2) and 114 +/- 51.0 (66-290), respectively. One hundred subjects, 50 in the low and 50 in the high activity group, were genotyped for CYP3A4*1B,*2,*4,*5,*6 and *10. Only 2 heterozygotes with genotype CYP3A4*1/*1B were found in the high CYP3A activity group. CYP3A4*2,*4,*5,*6 and *10 were not found in the subjects studied. CONCLUSION: This is the first investigation establishing CYP3A phenotypes and demonstrating the absence of common CYP3A4 genotypes in North Indians.
Eur J Clin Pharmacol. 2006 Apr 21;: 16628436 (P,S,G,E,B,D) Cited:2
Department of Biochemistry, Postgraduate Institute of Medical Education and Research, Chandigarh, UT-160 012, India, kris_kohli2003@yahoo.com.
OBJECTIVES: To phenotype 200 healthy North Indians for cytochrome P450 3A (CYP3A) activity by measuring urinary ratio of 6beta-OH-cortisol/cortisol (6beta-OH-CS/CS) and to genotype the subjects demonstrating low and high CYP3A activity for the presence of CYP3A4*1B,*2,*4,*5,*6 and *10 alleles. METHODS: Morning spot urine samples were collected from 200 healthy North Indians. CS and 6beta-OH-CS were extracted and quantified by HPLC. Genotyping was performed by polymerase chain reaction (PCR) followed by restriction fragment length polymorphism (RFLP). RESULTS: Urinary 6beta-OH-CS/CS ratio demonstrated a mean of 52.0 +/- 46 (1.1-290). North Indians demonstrated unimodal distribution with respect to urinary 6beta-OH-CS/CS ratio. On the basis of phenotypes, the subjects were divided into three groups demonstrating low (n=50), intermediate (n=100) and high (n=50) CYP3A activity. These groups demonstrated 6beta-OH-CS/CS ratio of 13.4 +/- 5.2 (1.1-21.0), 40 +/- 11.9 (21.2-63.2) and 114 +/- 51.0 (66-290), respectively. One hundred subjects, 50 in the low and 50 in the high activity group, were genotyped for CYP3A4*1B,*2,*4,*5,*6 and *10. Only 2 heterozygotes with genotype CYP3A4*1/*1B were found in the high CYP3A activity group. CYP3A4*2,*4,*5,*6 and *10 were not found in the subjects studied. CONCLUSION: This is the first investigation establishing CYP3A phenotypes and demonstrating the absence of common CYP3A4 genotypes in North Indians.
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