Predication of plasma concentration of remifentanil based on Elman neural network

Due to the nature of ultra-short-acting opioid remifentanil of high time-varying,complex compartment model and low-accuracy of plasma concentration prediction,the traditional estimation method of population pharmacokinetics parameters,nonlinear mixed effects model(NONMEM),has the abuses of tedious work and plenty of man-made jamming factors.The Elman feedback neural network was built.The relationships between the patients’plasma concentration of remifentanil and time,patient’age,gender,lean body mass,height,body surface area,sampling time,total dose,and injection rate through network training were obtained to predict the plasma concentration of remifentanil,and after that,it was compared with the results of NONMEM algorithm.In conclusion,the average error of Elman network is 6.34%,while that of NONMEM is 18.99%.The absolute average error of Elman network is 27.07%,while that of NONMEM is 38.09%.The experimental results indicate that Elman neural network could predict the plasma concentration of remifentanil rapidly and stably,with high accuracy and low error.For the characteristics of simple principle and fast computing speed,this method is suitable to data analysis of short-acting anesthesia drug population pharmacokinetic and pharmacodynamics.

Measurements of 5-FU Plasma Concentrations in Patients with Gastrointestinal Cancer: 5-FU Levels Reflect the 5-FU Dose Applied

Introduction: 5-Fluorouracil (5-FU) is the basis of most combination chemotherapies for gastrointestinal tumors. It is generally well tolerated, but side-effects might require dose-adjustment. As adverse events are not specific to the 5-FU component of the chemotherapy-combination, i.e. neutropenia, diarrhea or cardiotoxicity, the knowledge of 5-FU serum levels might help to attribute these side effects to the 5-FU compound. The optimal concentration-range (AUC, area under the curve) has been described to be within 20-25 mgh/l. The aim of this study was to analyse the intra- and interindividual variability of 5-FU AUC-levels in patients with 5-FU infusion therapy. Methods: 230 blood samples were obtained from 31 different gastrointestinal cancer patients (esophagus (8), stomach (10), ileum (1), colorectum (12)) treated with 5-FU-infusional regimes, based on a 24- or 48-hour AIO treatment-schedule. 5-FU plasma concentrations were measured using an immunolinked Elisa assay (Saladax 5-FU PCMTM). Intra- and interindividual differences were analysed before (0 h;n = 115), at 2 - 3 hours after the start of infusional 5-FU treatment (n = 19) (early sampling) and towards the end of the infusion (n = 96) (late sampling). Results: Early blood sampling resulted in low 5-FU plasma concentrations (541 ± 127 g/ml) due to saline prefilling (2 - 3 ml) of the Baxter pump. Blood sampling at the later time-point resulted in reproducible values (971 ± 81 ng/ml). 5-FU concentrations were dose-dependent with low intra- and interindividual variability. However, care has to be taken, as the results can be influenced by inaccurate blood sampling: too early or late sampling (when the folfusor-pump is empty), delayed centrifugation of the tube or hemolysis. Conclusions: With critical analysis of the measurements and correct performance of blood sampling, the measurement of 5-FU plasma concentrations with the immunoassay may in the future allow to optimize 5-FU dosing and to identify the cause of toxicity. Changes of 5-FU clearance in long-term therapy still have to be studied.

Over Exposure to Efavirenz Plasma Concentrations among Beninese HIV Patients Treated by A 600 mg Daily Dose

Therapeutic plasma concentrations of EFV （efavirenz） are between 1,000 ng/mL and 4,000 ng/mL. Concentrations below 1000 ng/mL are associated with higher risk of treatment failure, and concentrations above 4,000 ng/mL are associated with toxicity. The aim of the study was to appreciate EFV plasmas concentrations profile and the association between plasma levels and various characteristics in Beninese patients treated by a 600 mg standard daily-dose. Blood samples were collected and EFV plasma levels were measured by liquid chromatography coupled with mass spectrometry detection in HIV-infected patients receiving EFV in combination with other antiretroviral drugs for at least 14 days. Adverse effects occurring during treatment were collected through a questionnaire. An over-exposure to EFV among Beninese HIV patients were observed, with 46.4% of patients presenting EFV concentration above 4,000 ng/mL, although adverse effects were tolerated indicating that antiretroviral treatment is safe. The measurement of plasma concentration at the steady-state could contribute to early detection of treatment failure and adapt treatment in subjects presenting serious adverse effects within context of therapeutic drug monitoring.

Relationship between plasma risperidone concentrations and clinical features in chronic schizophrenic patients in China

BACKGROUND Prior studies have noted great variability in the plasma levels of risperidone(RIS).Plasma concentrations of RIS and its active moiety are highly variable and depend on absorption,metabolism,and other predictors of metabolic dysregulation;however,these factors are poorly understood and the association between metabolic change and change in psychopathology is uncertain.AIM To ascertain the characteristics of chronic schizophrenic patients treated with RIS,and to assess their relationship with plasma RIS levels.METHODS This was a descriptive cross-sectional study of 50 patients with a diagnosis of schizophrenic psychosis treated with RIS in a psychiatric service.The plasma concentrations of RIS and its metabolite 9-hydroxyrisperidone were determined by high performance liquid chromatography.The patients’demographic and clinical characteristics,and psychopathologies were assessed,and the associations between clinical variables and plasma levels of RIS were explored.RESULTS Male patients received higher doses of RIS than female ones,but plasma concentrations of RIS and risperidone+9-hydroxyrisperidone(active moiety)were higher in female patients.Age and the mean scores of the general psychopathology subscale of the Positive and Negative Syndrome Scale(PANSS)were significantly positively correlated with plasma concentrations of risperidone+9-hydroxyrisperidone adjusted for weight and dose in all 50 subjects.In male subjects,we found a statistically significant positive correlation between the concentrations of risperidone+9-hydroxyrisperidone in plasma/(dose×kg)and age,mean PANSS negative subscale scores,mean PANSS general psychopathology subscale scores,and mean PANSS total scores.CONCLUSION Long-term use of RIS should be closely monitored in older patients and females to minimize the risk of high concentrations which could induce side effects.

Determination of Lycopene Concentration in Dog Plasma by RP-HPLC

A method for determination of lycopene concentration in dog plasma wasestablished. Methods RP-HPLC was used; the mobile phase consisted of methanol-acetonitrile-methylenechloride (40:30:30, V/V) , the wavelength of detection was 472 nm, the column temperature wasambient temperature, and the flow rate was 1.0 mL·min^(-1). Results The standard curve was linearin the range from 0.012 4 to 0.496 μg·mL^(-1) with r=0.9992. The average extraction recovery was97.6% +-4.2%. The intra-day and inter-day RSD were 1.52% -4.95% and 2.31% -7.38%, respectively.Conclusion This method is sensitive, rapid, reproducible, and of good selectivity for the analysisof lycopene in dog plasma.

Effects of dietary Selenomethionine supplementation on growth performance,antioxidant status,plasma selenium concentration,and immune function in weaning pigs

Background： This study was designed to evaluate the efficacy of DL-selenomethionine （DL^SeMet） supplementation on growth performance, antioxidant status, plasma selenium （Se） concentration, and immune function of weaning pigs. 216 weaning pigs were randomly allocated to 6 treatments with 6 replicates each according to a complete randomized block design. Each replicate had six pigs. Diet of group one was corn-soybean basal diet without any additional Se supplement. Group 2 was supplemented with 0.3 mg/kg of Se from sodium selenite. Groups 3-6 were supplemented with 0.1, 0.3, 0.5, and 0.7 mg/kg of Se from DL-SeMet, respectively. The trial lasted for 42 days. Results： Pigs supplemented with 0.3 and 0.7 mg/kg DL-SeMet obtained better feed gain ratio （P 〈 0.05）. The best antioxidant ability （serum, liver, and muscle） was shown in 0.1-0.3 mg/kg DL-SeMet groups （P〈 0.05）. The plasma Se concentration increased as the dietary DL-SeMet level elevated. The immunity among groups was not affected. Conclusions： DL-SeMet supplementation in the diet significantly improved the growth performance, antioxidant ability and plasma Se content of weaning pigs. DL-SeMet can replace sodium selenite in the diet of weaning pigs.

Study on the Relationship between Plasma very Low Density Lipoprotein Concentration and Egg Composition Traits in Layer Type Chickens

The chickens used in this study were from a pure line of brown shell egg-type (YAFA) female grandparents of 17-week-old. Plasma very low density lipoprotein (VLDL) concentration was measured with turbidimetric assay. The experimental results showed that there was a close relationship between plasma VLDL concentration and egg composition traits, and a positive phenotypic correlation trend was found between 29-week plasma VLDL concentration and 44-week yolk weight, and the genetic correlation coefficient was 0.234. Both the phenotypic and genetic correlations between 29-week plasma VLDL concentration and albumen weight were negative. Significant positive phenotypie correlations were, however, observed between yolk ratio, or the yolk/albumen ratio and 29-week plasma VLDL concentration, and their genetic correlation coefficients were 0.250 and 0.223, respectively.

The Influence of Selection for Plasma very Low Density Lipoprotein Concentration upon Production Performance in Layer Type Chickens

The chickens studied were from a pure line of brown shell egg-type (YAFA) female grandparents of 17-week-old. Plasima very low density lipoprotein (VLDL) concentration was measured with turbidimetric assay. The experiment results showed that the phenotypic correlations between 29-week or 50-week plasma VLDL concentration and egg production (EP) were positive in the early stage of laying period, but those in the latter stage were negative. Selection for low plasma VLDL concentration will decrease the EP in the early stage of laying period but increase the one in the latter stage. There was a significant negative phenotypic correlation between the age at first egg (AFE) and 18-week body weight (BW). The phenotypic correlation between 29-week plasma VLDL concentration and the AFE was negative. AFE was influenced by BW and body fatness as well. There was significant positive phenotypic correlation between plasima VLDL concentration and body weights (BWs) at the same stage in laying period and the phenotypic correlation was also positive between 29-week plasma VLDL concentration and the BW at middle stage of laying period, indicating that selection for low plasma VLDL concentration would reduce BWs at various stages to different degree.

Studies on the Analytical Method for a New Antiarrhythmic Guanfu Base A in Rabbit Plasma

Guan-fu base A(GFA),a new antiarrhythmic alkaloid with a structure of C_(20)-diterpenoid could react rapidly and quantitatively with trifluoroacetic anhydride(TFAA) to produce GFA—TFAA of which the structure was identified by GC—MSD.There was a wide linear range of the GC-ECD method from 10 to 20000ng/ml(r=0.9984).The average recovery of GFA from the spiked plasma was 97.52%.The coefficients of variation of within-day and between-day were less than 7% and 9%,respectively.The method was used in the preclinical experiment of pharmacology of GFA and the results showed that GFA con- centrations in rabbits' plasma within 6 hours after the administration ranged from 0.338± 0.014 to 13.459±5.393μg/ml for dosage 10mg/kg,from 0.133±0.038 to 2.546±0.480 μg/ml for dosage 2mg/kg and from 45.25±10.34 to 535.86±24.36ng/ml for dosage 0.4 mg/kg.

Differences Between the Concentrations in Rabbit Body Fluid of Berberine Hydrochloride, Chlorogenic Acid, Baicalin, and Their Minimal Inhibitory Concentrations

To explore the relationship between the heat-clearing and detoxicating functions and the bacteriostatic actions of berberine hydrochloride （Ber. H）, chlorogenic acid （Chlo. A）, and baicalin （Bai）, their concentrations in rabbit body fluid were compared with their minimal inhibitory concentrations （MICs）. Their concentrations in rabbit blood and tissue fluid were determined by reversed-phase high performance liquid chromatography, and their MICs to Escherichia coli were determined by tube dilution method. The results showed that the peak concentrations of Ber. H, Chlo. A, and Bai in rabbit blood were 3.2, 5.03, and 7.63 μg mL^-1, and in rabbit tissue fluid were 0.12, 0.11, and 0.12 μg mL^-1, respectively. Their MICs to E. coli were, respectively, 1.0×10^3, 3.75 × 10^3, and 6.75 ×10^3μg mL^-1, which were far higher than the concentrations in rabbit body fluids. This study indicates that Ber. H, Chlo. A, and Bai have weak bacteriostatic actions and do not reach their effective inhibitory concentrations in rabbit body fluids, and their heat-clearing and detoxicating functions are independent on the bacteriostatic actions.

17α,20β-DIHYDROXY-4-PREGNENE-3-ONE SUPPRESSES PLASMA IgM LEVELS IN RAINBOW TROUT (Oncorhynchus mykiss)

The relationships between 17α,20β dihydroxy 4 pregnene 3 one (17α,20β DP) and plasma IgM and total protein levels were investigated in rainbow trout, Oncorhynchus mykiss .IgM and total protein levels decreased in both sexes of mature rainbow trout when 17α,20β DP levels increased during the spawning season,while the elevated 17α,20β DP suppressed IgM levels and reversibly enhanced total protein concentrations in immature trout.This represents the first report of the effect of 17α,20β DP on fish immunity.These data suggest that the increase of 17α,20β DP in spawning season may be related to infectious skin diseases.

The Change of Plasm a very Low Density Lipoprotein Concentration Pre-or Post-Feeding and in Conrrelation with Body Fatness Traits in Broiler Chickens

Blood samples were taken from birds,from a commercial line of broiler chicken,being in a fully fed state and in fasting state for 2,4,6 hours respectively at 49 d of age and plasma very low density lipoprotein(VLDL) concentration was measured with turbidimetric assay.The experiment results showed that the variation coefficients of plasma VLDL concentration mersured at four different times were 58.11%,74.39%,69.70%,47.83%,respectively for male broilers,and 41.82%,60.87%.59.26%,50.0%for female broilers respectively.Plasma VLDL concentration decreased with the fasting time.There was a significant positive phenotypic correlation between abdominal fat weight,percentage of abdominal fat and plasma VLDL concentration for the birds being in fully feeding state,and the correlation decreased or no longer existed for the bired being in fasting state.The conclusion was that for practically application of plasma VLDL content selected in broiler chicken breeding,blood samples should be collected from birds being in feeding state.

Effects of dietary forage to concentrate ratio and wildrye length on nutrient intake, digestibility, plasma metabolites, ruminal fermentation and fecal microflora of male Chinese Holstein calves

Twenty-eight male, weaned Chinese Holstein calves（（156.8±33.4） kg） were used to investigate the effects of dietary forage to concentrate ratio（F：C） and forage length on nutrient digestibility, plasma metabolites, ruminal fermentation, and fecal microflora. Animals were randomly allocated to four treatments in a 2×2 factorial arrangement： whole-length forage（WL） with low F：C（50：50）; WL with high F：C（65：35）; short-length forage（SL） with high F：C（65：35）; and SL with low F：C（50：50）. Chinese wildrye was used as the only forage source in this trial. The grass in the SL treatments was chopped using a chaff cutter to achieve small particle size（-50% particles 〉19 mm）. Dry matter intake（DMI） and organic matter（OM） intake was increased by increasing both F：C（P〈0.01） and forage length（FL）（P〈0.05）, while acid detergent fiber（ADF） and neutral detergent fiber（NDF） intakes were only increased by increasing the F：C（P〈0.01）. The digestibility of NDF was increased as the FL increased（P〈0.01）, and it was also affected by interaction between F：C and FL（P〈0.05）. Cholesterol（CHO）（P〈0.01）, leptin（LP）（P〈0.05）, and growth hormone（GH）（P〈0.01） concentrations in plasma were increased as dietary F：C increased. A significant increase in plasma triglyceride（TG）（P〈0.01）, insulin（INS）（P〈0.05）, and GH（P〈0.01） levels was observed with decreasing dietary FL. Ruminal p H values of calves fed with low F：C diets were significantly lower than those in high F：C treatment（P〈0.05）. Increasing the F：C enhanced ruminal acetic acid（P〈0.05） and acetic acid/propionic acid（P〈0.01）. Fecal Lactobacillus content was significantly higher, while Escherichia coli and Salmonella contents were significantly lower in WL and high F：C groups（P〈0.05）. Lower fecal scores（higher diarrhea rate） were observed in calves fed with SL hay compared to WL hay（P〈0.05）. Denatured gradient gel electrophoresis（DGGE） bands and richness index（S） were significantly affected by the interaction between F：C and FL（P〈0.05）, under high F：C, band numbers and richness index from WL group were higher than that from SL group（P〈0.05）, whereas there were no differences between WL andSL groups under low F：C（P〉0.05）. Microflora similarity was 50–73% among the different treatments. It is concluded that the WL with high F：C（65：35） diet is suitable for weaned calves.

高效液相色谱-离子阱质谱法测定人血浆中的头孢拉定和青霉素G

目前,β-内酰胺类抗生素在临床抗感染药物中占有十分突出的地位[1],但在近年来的药品不良反应报告中,抗生素类药物引起的不良反应也占据了很高的比例,其中有我国生活环境影响、感染性疾病多的客观因素,但病人用药盲目性大、医生用药随意性多的问题也普遍存在.……

Growth rate,body composition, digestive enzymes and transaminase activities,and plasma ammonia concentration of different weight Jian carp(Cyprinus carpio var. Jian)

The present study investigated the effect of body weight on body composition, digestive and absorptive capacity, transaminase activities in hepatopancreas and muscle, and plasma ammonia concentration of Jian carp(Cyprinus carpio var.Jian). A total of 750 Jian carps(18.0 ± 0.2 g) were randomly distributed into five groups with three replicates and fed the same diet for 56 days. Tissue and plasma samples were collected on days 14, 28,42, and 56. The results were used to develop a mathematical model for specific growth rate, body moisture and fat content, aspartate transaminase activity and alanine aminotransferase activity in hepatopancreas and muscle, plasma ammonia concentration, and trypsin, chymotrypsin, lipase, and amylase activities in hepatopancreas and intestine, activities of creatine kinase, Na^+/K^+-ATPase, alkaline phosphatase, and γ-glutamyl transpeptidase in intestine in Jian carp. There were linear relationships between natural logarithms of above indexes and body weight. The body moisture and fat content, digestive and absorptive enzymes activities, and transaminase activities showed negative allometry against body weight of Jian carp which were partial reasons to explain fish growth rate decreasing.

Diagnostic value of aldosterone to renin ratio calculated by plasma renin activity or plasma renin concentration in primary aldosteronism: a meta-analysis

Background:Since the diagnostic value of aldosterone to renin ratio(ARR)calculated by plasma renin concentration(PRC)or plasma renin activity(PRA)is still inconclusive,we conducted a meta-analysis by systematically reviewing relevant literature to explore the difference in the diagnostic efficacy of ARR calculated by PRC or PRA,so as to provide guidance for clinical diagnosis.Methods:We searched PubMed,Embase,and Cochrane Library from the establishment of the database to March 2021.We included studies that report the true positive,false positive,true negative,and false negative values for the diagnosis of primary aldosteronism,and we excluded duplicate publications,research without full text,incomplete information,or inability to conduct data extraction,animal experiments,reviews,and systematic reviews.STATA 15.1 was used to analyze the data.Results:The pooled results showed that ARR(plasma aldosterone concentration[PAC]/PRC)had a sensitivity of 0.82(95%confidence interval[CI]:0.78-0.86),a specificity of 0.94(95%CI:0.92-0.95),a positive-likelihood ratio(LR)of 12.77(95%CI:7.04-23.73),a negative LR of 0.11(95%CI:0.07-0.17),and symmetric area under the curve(SAUC)of 0.982,respectively.Furthermore,the diagnostic odds ratio(DOR)of ARR(PAC/PRC)was 180.21.Additionally,the pooled results showed that ARR(PAC/PRA)had a sensitivity of 0.91(95%CI:0.86-0.95),a specificity of 0.91(95%CI:0.90-0.93),a positive LR of 7.30(95%CI:2.99-17.99),a negative LR of 0.10(95%CI:0.04-0.26),and SAUC of 0.976,respectively.The DOR of ARR(PAC/PRA)was 155.52.Additionally,we conducted a subgroup analysis for the different thresholds(<35 or≥35)of PAC/PRC.The results showed that the DOR of the cut-off≥35 groups was higher than the cut-off<35 groups(DOR=340.15,95%CI:38.32-3019.66;DOR=116.40,95%CI=23.28-581.92).Conclusions:The research results suggest that the determination of ARR(PAC/PRC)and ARR(PAC/PRA)was all effective screening tools for PA.The diagnostic accuracy and diagnostic value of ARR(PAC/PRC)are higher than ARR(PAC/PRA).In addition,within a certain range,the higher the threshold,the better the diagnostic value.

Specific acupuncture stimulation of Shenshu(BL23)affects sympathetic nervous activity-associated plasma renin concentration changes

OBJECTIVE:To examine whether specific stimulation of Shenshu(BL23)affects sympathetic nervous activity(SNA)-associated plasma renin concentration(PRC).METHODS:Eight healthy volunteers participated in three pattern conditions in random order:control(Cont),stimulation of Shenshu(BL23),and stimulation of sham point(Sham).All participants were initially in the supine position for>60 min,and then remained in the standing position during the experimental procedure to increase SNA.An electrocardiogram was used to calculate low frequency/high frequency(LF/HF)ratio;blood was collected to analyze PRC.RESULTS:The LF/HF ratio was significantly increased in the standing position when compared with the supine position(P<0.01).There was no difference in LF/HF ratio during or after stimulation of Shenshu(BL23)in the standing position when compared with before the stimulation in the supine position;however,the LF/HF ratio was significantly increased in Cont and Sham conditions(P<0.01).There was no difference in PRC after stimulation of Shenshu(BL23)in the standing position when compared with before the stimulation in the supine position;however,there was a significant increase in PRC in the Cont and Sham conditions(Cont P<0.05,Sham P<0.01).CONCLUSION:Our results demonstrated that specific acupuncture stimulation of Shenshu(BL23)in the standing position decreased SNA-associated PRC,which was not observed during acupuncture stimulation of the sham point.

Mechanism of hyperproteinemia-induced blood cell homeostasis imbalance in an animal model

Hyperproteinemia is a metabolic disorder associated with increased plasma protein concentration(PPC)and is often clinically complicated by malignant diseases or severe infections.At present,however,research on the molecular mechanism underlying high PPC(HPPC)is scant.Here,an animal model of primary hyperproteinemia was constructed in an invertebrate(Bombyx mori)to investigate the effects of HPPC on circulating blood cells.Results showed that HPPC affected blood cell homeostasis,leading to increased reactive oxygen species levels,and induced programmed cell death dependent on the endoplasmic reticulum-calcium ion signaling pathway.HPPC induced the proliferation of blood cells,mainly granulocytes,by activating the Janus kinase/signal transducer and activator of transcription(JAK/STAT)signaling pathway.Supplementation with the endocrine hormone active substance 20 E significantly reduced the impact of HPPC on blood cell homeostasis.Thus,we identified a novel signaling pathway by which HPPC affects blood cell homeostasis,which differs from hyperglycemia,hyperlipidemia,and hypercholesterolemia.In addition,we showed that down-regulation of gene expression of the hematopoietic factor Gcm could be used as a potential early detection indicator for hyperproteinemia.

Rapid determination of quercetin-3'-O-glucoside in rat plasma by high performance liquid chromatography-tandem mass spectrometry

A method for the quantification of quercetin-3’-O-glucoside in rat plasma by high-performance liquid chromatography-tandem mass spectrometry（HPLC-MS/MS） was developed and validated.Along with internal standard（carbamazepine）,quercetin-3’-O-glucoside was extracted from plasma samples by simple liquid-liquid extraction with ethyl acetate.The mass spectrometry detection was set in multiple reaction monitoring（MRM） mode via positive electrospray ionization（ESI）.The chromatographic run time was 3.5 min per sample.The calibration curves were linear（r^2 = 0.9992） with a lower limit of quantification（LLOQ） of 10.625 ng/mL,and the limit of detection（LOD） was 4.25 ng/mL.The intra-and inter-day precision and accuracy,in terms of relative standard deviation（RSD）,were all lower than 10.44%.The recovery rate of the analyte and internal standard were higher than 66.80%.After intravenous administration of 10 mg/kg quercetin-3’-O-glucoside,the t1/2 and AUC were（0.02±0.01） h and（1.22±0.28）×10^4 μg/L·h.The method is accurate,stable and sensitive,which is suitable for the pharmacokinetic study of quercetin-3’-O-glucoside in rats.

Rapid and sensitive HPLC-MS/MS method for quantitative determination of isochlorogenic acid B in rat plasma and its application in pharmacokinetic study

A sensitive LC-ESI-MS/MS method for determination of isochlorogenic acid B in rat plasma was developed and validated in the present study. Plasma samples were prepared by a simple protein precipitation with methanol containing resveratrol as internal standard (IS). The chromatographic separation was performed on a Zorbax SB-Cjg column (3.5 pm, 2.1 mmx 100 mm, Agilent, USA) at a flow rate of 0.2 mL/min using methanol/water containing 0.1% formic acid (v/v) as mobile phase. The detection was performed on a triple quadrupole tandem mass spectrometer equipped with Electronic Spray Ion by selected reaction monitoring (SRM) of the transitions at m/z 515.3->352.9 for isochlorogenic acid B and m/z 227.1-143.1 for IS, respectively. The calibration curve of the method was linear over the range of 5-2500 ng/mL (r^2= 0.9982). The intra- and inter-day precisions (R.S.D.%) were less than 12.46%, and the accuracy (R.E.%) was within ±5.80%. Isochlorogenic acid B was sufficiently stable under all relevant analytical conditions. The validated method was successfully applied to the plasma pharmacokinetic studies of isochlorogenic acid B in rats. It was found that isochlorogenic acid B had non-linear pharmacokinetic characteristics in rats within the dosage ranges from 5 to 20 mg/kg.