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Objective:To explore the disturbance of metal element balance in mice after exposure to radon.Methods:Mice were randomly divided into control group, radon exposure of 30 WLM group, 60 WLM group and 120 WLM groups, with 10 mice in each group. After radon exposure with the cumulative dose, the lung function of mice was detected by a non-invasive pulmonary function testing instrument. Mice blood was taken from eyeballs. The lungs, heart, liver, kidney and spleen were also collected. HE staining was used to observe the pathological changes of lung tissue. Inductively coupled plasma mass spectrometry (ICP-MS) was used to detect the content of metal elements, including essential trace elements in the body: chromium (Cr), molybdenum (Mo), cobalt (Co), selenium (Se), copper (Cu), zinc (Zn), manganese (Mn), nickel (Ni), and potentially toxic elements: arsenic (As), tin (Sn), lead (Pb), aluminum (Al), mercury (Hg), cadmium (Cd), and silver (Ag).Results:Compared with the control group, lung ventilation function of the radon-exposed mice was decreased, alveolar structure was destroyed, and the contents of pulmonary metal elements Cr, Al, Pb, Sn( F=0.34, 0.66, 3.14, 1.16, P<0.05) and essential trace elements Mn, Cr, Zn, and Mo in the blood were decreased( F=0.65, 1.44, 0.97, 2.08, P<0.05), while the elements of Cu, Mo, Se and As in the lungs were increased( F=1.31, 1.26, 0.81, 2.04, P<0.05), and the element contents in other tissues also fluctuated. Conclusions:Inhalation of a certain cumulative dose of radon can reduce the lung ventilation function of mice and induce lung inflammation, as well reduce the content of essential trace elements in the lung and blood so that the content of metal elements in the body fluctuates.
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PEP06 is a novel endostatin-Arg-Gly-Asp-Arg-Gly-Asp(RGDRGD)30-amino-acid polypeptide featuring a terminally fused RGDRGD hexapeptide at the N terminus.The active endostatin fragment of PEPO6 directly targets tumor cells and exerts an antitumoral effect.However,little is known about the kinetics and degradation products of PEP06 in vitro or in vivo.In this study,we investigated the in vitro metabolic stability of PEP06 after it was incubated with living cells obtained from animals of different species;we further identified the degradation characteristics of its cleavage products.PEP06 underwent rapid enzymatic degradation in multiple types of living cells,and the liver,kidney,and blood play important roles in the metabolism and clearance of the peptides resulting from the molecular degradation of PEP06.We identified metabolites of PEP06 using full-scan mass spectrometry(MS)and tandem MS(MS2),wherein 43 metabolites were characterized and identified as the degradation metabolites from the parent peptide,formed by successive losses of amino acids.The metabolites were C and N terminal truncated products of PEP06.The structures of 11 metabolites(M6,M7,M16,M17,M21,M25,M33,M34,M39,M40,and M42)were further confirmed by comparing the retention times of similar full MS spectrum and MS2 spectrum information with reference standards for the synthesized metabolites.We have demonstrated the metabolic stability of PEP06 in vitro and identified a series of potentially bioactive downstream metabolites of PEP06,which can support further drug research.
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Objective To establish a rapid LC-MS/MS method for the simultaneous quantitative determination of lopinavir (LPV)and ritonavir(RTV)in human plasma. Methods Plasma samples were prepared by protein precipitation and separated by a Thermo Hypersil GOLD column(2.1 mm×100 mm,5 mm)with the mobile phase consisting of methanol and water(0.1%formic acid) at a flow rate of 0.2 ml/min. Detection of LPV,RTV and the internal standard(IS)MS 275 was performed using selected reaction moni?toring(SRM)of the transitions m/z 629.3→155.0,m/z 721.3→268.0 and m/z 377.1→359.2 in positive ion mode,respectively. Re?sults The calibration curve was linear in the range of 20-1000 ng/ml(r>0.994)for LPV and RTV. The intra and inter-day precision and accuracy values met the set acceptance criteria. Conclusion The method is rapid,sensitive and accurate for the therapeutic drug monitoring of LPV and RTV simultaneously in clinic and pharmacokinetic studies.
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Objective To establish a chemiluminescent immunoassay method for the determination of cathelicidin-BF(BF-30)in rat serum,to provide a fast and simple analytical method for its pharmacokinetic studies,then to investigate the pharmacokinet?ic characteristics of BF-30 in vivo. Methods A chemiluminescent immunoassay method was developed and the matrix effect,preci?sion,accuracy,stability and the dilution effect were evaluated,then the method was used to determine the concentration of BF-30 in rat serum. Results The linear range of BF-30 in rat serum was 0.5-40 ng/ml,and the lowest limit of determination was 0.5 ng/ml. No matrix effect was observed. The RSD of inter-and intra-day precisions were 8.76%-14.15%and 4.91%-11.11%,respectively,and ac?curacy was-1.27%--7.71%. The stability of samples for 13 days and stock solution for 30 days at-20℃were good,and the stability of serum samples after 2 cycles of freeze-thaw met the requirements. There was no dilution effect noted after 40 times sample dilution. Conclusion We heve developed a simple,accurate and reliable method which can be applied to the determination of BF-30 in rat se?rum and following pharmacokinetic study.
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Objective To establish an ultra-high-performance liquid chromatograph(UHPLC)method for the determination of paclitaxel (PTX)in polydipeptide paclitaxel (PDP)preparation. Methods PDP preparation was dissolved in deionized water (DIW) and degraded by 2.0 mol/L sodium hydroxide solution. The concentration of paclitaxel was calculated indirectly by its degradation product. The separation was achieved on an Agilent SB C18 column(2.1 mm × 50 mm,1.8μm). Elution was carried out using a mobile phase consisting of acetonitrile-water (10 ∶ 90,V/V)at the flow rate of 0.2 ml/min. UV detection wavelength was performed at 240 nm and reference wavelength was 360 nm. The temperatures of autosampler and column were thermostated at 15℃(± 0.5℃)and 40℃(± 0.5℃),respectively. The injection volume was 2 μl. Results The relationship between the concentration of paclitaxel (0.31-5.00 mg/ml)and the peak area of its degradation product was in good linearity (r=0.9992,n=5). Total amount of paclitaxel in different batches of PDP preparation was in the range of 26.77-33.19 mg per vial. Conclusion The method is accurate, rapid,reproducible and suitable for the analysis of paclitaxel in PDP preparation.
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A rapid, sensitive and simple liquid chromatography-tandem mass spectrometric (LC-MS/MS) method was developed for the simultaneous determination of yogliptin and its metabolite in Wistar rat plasma. Linagliptin and dexamethasone were chosen as the internal standards of yogliptin and its metabolite, (R)-8-(3-hydroxypiperidine- -yl)-7-(but-2-yn-1-yl)-1-((5-fluorobenzo[d]thiazol-2-yl)methyl)-3-methyl- H-purine-2, 6 (3H, 7H)-dione, respectively. After a simple protein precipitation using acetonitrile as the precipitating solvent, both analytes and ISs were separated on a Grace Altima HP C18 column (2.1 mm x 50 mm, 5 microm) with gradient elution using methanol (containing 0.1% formic acid, 4 mmol x L(-1) ammonium acetate)-0.1% formic acid (containing 4 mmol x L(-1) ammonium acetate) as the mobile phase. A chromatographic total run time of 4.4 min was achieved. Mass spectrometric detection was conducted with electrospray ionization under positive-ion and multiple-reaction monitoring modes. Linear calibration curves for yogliptin and its metabolite were over the concentration range of 0.5 to 500 ng x mL(-1) with a lower limit of quantification of 0.5 ng x mL(-1). The intra- and inter- assay precisions were all below 14%, the accuracies were all in standard ranges. The method was used to determine the concentration of yogliptin and M1 in Wistar rat plasma after a single oral administration of yogliptin (27 mg x kg(-1)). The method was proved to be selective, sensitive and suitable for pharmacokinetic study of yogliptin and M1 in Wistar rat plasma.
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This paper is to report the study of the metabolism of forscolin in plasma and liver microsomes for guiding clinical therapy. Forscolin was quantified by HPLC-MS/MS. The metabolic stability of forscolin in rat, Beagle dog, monkey and human plasma and liver microsomes, mediated enzymes of forscolin and its inhibition on cytochrome P450 isoforms in human liver microsomes were studied. Results showed that forscolin was not metabolized in plasma of the four species but metabolized in liver microsomes of the four species. The t1/2 of forscolin in rat, Beagle dog, monkey and human liver microsomes were (52.0 +/- 15.0), (51.2 +/- 5.9), (6.0 +/- 0.2) and (11.9 +/- 1.8) min; CL(int) were (75.6 +/- 18.7), (60.9 +/- 6.8), (513.8 +/- 14.3) and (176.2 +/- 25.6) mL x min(-1) x kg(-1); CL were (34.8 +/- 4.5), (23.3 +/- 1.0), (40.3 +/- 0.5) and (17.9 +/- 0.3) mL x min(-1) x kg(-1), respectively. Forscolin was metabolized by CYP3A4 in human liver microsomes. There was definite inhibition on CYP3A4 at the concentrations of forscolin between 0.1 ng x mL(-1) and 5 microg x mL(-1). Therefore, forscolin is rapidly excreted from liver microsomes. Attention should be paid to the drug interaction when forscolin was used along with other drugs metabolized by CYP3A4 in clinics.
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Healthy Beagle dogs were administrated with batroxobin by intravenous infusion at high, medium and low doses. The study of pharmacodynamics and pharmacokinetics was intended to clarify the relevance of them and provided strong evidence for clinical use of batroxobin. The blood samples were collected after injection based on the time schedule and samples were tested by ELISA method to get the concentration of batroxobin. At the same time, changes of prothrombin time (PT), thrombin time (TT), activated partial thromboplastin time (APTT), fibrinogen (Fib) and D-dimmer were tested. The results showed that the concentration of D-D increased significantly after administration compared with that of before administration. The main pharmacokinetic parameters were as follows: t1/2 were (2.27 +/- 0.42) h, (10.65 +/- 2.19) h and (11.01 +/- 3.51) h; C(max) were (11.9 +/- 1.72) ng x mL(-1), (154.53 +/- 12.38) ng x mL(-1) and (172.14 +/- 47.33) ng x mL(-1); AUC(last) were (29.38 +/- 3.69) ng xh x mL(-1), (148.43 +/- 72.85) ng x h x mL(-1) and (599.22 +/- 359.61) ng x h x mL(-1). The elimination of batroxobin was found to be in accord with linear kinetics characteristics. The results of pharmacodynamics showed that D-dimmer level increased significantly after the administration of batroxobin, which was similar with the changes of batroxobin plasma concentration. Simultaneously, Fib concentrations in Beagle dog blood decreased significantly after the iv administration of batroxobin, while recovered to base level after 48 hours. PT, TT and APTT significantly became longer after administration, which returned to normal level after 48 hours. Especially, the D-dimmer levels and the batroxobin concentration in plasma after intravenous infusion of the drug were synchronized in Beagle dogs. Changes between PD/PK results had obvious correlation, and the D-dimmer levels in plasma can be one of the important monitoring indicators of batroxobin in thrombolytic medication.
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Objective To develop a sensitive liquid chromatography-tandem mass spectrometric (LC-MS/MS) method for the determination of forsklin in rat plasma.Methods After extraction with methyl tert-butyl ether,chromatographic separation was performed on a C18 column with the mobile phase consisting of water ( 0.1％ formic acid)-acetonitrile in a gradient elution mode.A tandem mass spectrometer equipped with electrospray ionization (ESI) source was used as detector in the positive ion mode.Quantification was performed using multiple reaction monitoring (MRM) with the precursor product combination ions of m/z 411→375.3 and 285→193 for forsklin and diazepam.Results Good linearity was obtained in the 0.5-1000 ng/ml range for the analyte and the analytical method was validated in terms of specificity,precision,accuracy,recovery,stability and matrix effect.These assays gave RSD values always lower than 14.4％ and RE values between -3.5 ％ and 3.8％.In addition,the specificity,extraction recovery,stability and matrix effect were satisfactory.Conclusion Due to its high sensitivity,specificity and simplicity,the method could be used for pharmacokinetic studies of forsklin.
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This paper is to report the study of the metabolism of lidamycin in vitro including in plasma and microsomes to guide clinical therapy. Lidamycin was quantified by detecting its active ingredient using HPLC-MS/MS. The metabolic stability of lidamycin in rat, Beagle dog, monkey and human plasma and liver microsomes, and its inhibition to cytochrome P450 isoforms in human liver microsomes were studied. Results showed that lidamycin was metabolized in the four species of plasma, and the sequence of metabolic rates in plasma were in rat > in dog > in human > in monkey. But among the four species of liver microsomes, lidamycin was metabolized only in monkey liver microsomes. There was almost no inhibition to cytochrome P450 isoforms at the concentrations of between 0.0005 and 10 ng x mL(-1). Therefore, the property of lidamycin metabolism in human is similar with that in dog, and metabolism of other drugs would not be decreased by cytochrome P450 as used along with lidamycin in clinic.
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Abstract: This study is to elucidate the metabolic pathway of 1,2-[bis (1,2-benzisoselenazolone-3 (2H)-ketone)]-ethane (BBSKE) in rats. Rats were administrated with a single dose of BBSKE 200 mg x kg(-1). The metabolites in rat urine, feces, bile and plasma were identified by LC-MSn analysis. The characterization of fragment ions from LC-MSn chromatography and mass spectrometry was applied to the investigation of structures of metabolites. Three phase I metabolites were detected in rat urine and feces. Two of them were also found in plasma and one existed in bile. These products were derived from oxidized, methylated and S-methylated BBSKE, separately. One phase II glucuronide of BBSKE was also found in bile. Therefore, it is possible that BBSKE was metabolized by oxidization, methylation and glucuronidation.