ABSTRACT
OBJECTIVE: To establish a method for the determination of norathyriol in rat plasma by HPLC and to study its characteristics of pharmacokinetics. METHODS: Ethyl formic acid(10:1) was used to precipitate protein in the plasma samples after the addition of internal standard, and then the concentration was analyzed by HPLC. All of the separations were carried out on a Platisil ODS(4.6 mm×250 mm, 5 μm) at room temperature. The mobile phase was consisted of formic acid(40:60:0.5, pH 2.74), and was pumped at flow rate of 0.8 mL·min-1. The UV detection wavelength was set at 312 nm. The rats were given norathriol by intragastric administration with a dosage of 400 mg·kg-1. The concentration of norathriol in plasma at different time points was determined. RESULTS: A good linear relationship was obtained in the concentration range of 0.54-162 μg·mL-1(r=0.998). The intra-day and inter-day RSD were less than 7.5%. The main pharmacokinetic parameters measured by Winnonlin 6.1 were showed as follows: tmax, t1/2, ρmax and AUC0-t were 0.5 h, (3.46±0.903) h, (26.9±3.17)μg·mL-1, (52.4±12.0) μg·h·mL-1, respectively. CONCLUSION: The HPLC method established is rapid and specific, and can be successfully applied in basic pharmacokinetic study in rat plasma.
ABSTRACT
<p><b>OBJECTIVE</b>To observe the functional magnetic resonance imaging (fMRI) data changes of default mode network (DMN) in chronic sciatica patients in the resting network state treated by acupuncture, and to study the correlation between DMN and the consisting effects after acupuncture analgesia.</p><p><b>METHODS</b>Weizhong (BL40) and Huantiao (GB30) of the patients' lower limbs were selected as the main points to acupuncture for ten times. The whole brain was scanned using fMRI. The independent component analysis (ICA) was adopted to get DMN information. The brain DMN function link was analyzed in the two groups of subjects.</p><p><b>RESULTS</b>The DMN images were obtained in all subjects after DMN fMRI data processing. The main DMN differences between the sciatica patients group and the healthy control group were demonstrated as decreased activities of DLPFC and anterior cingulate cortex (ACC). After acupuncture, activities of these regions basically recovered to normal. The DMN of healthy volunteers shown by fMRI data in the RNS mainly existed in the precuneus, BA7, BA10, and ACC.</p><p><b>CONCLUSION</b>MRI images of DMN in the RNS could reflect chronic pain, which was suitable for studies on the effects after acupuncture analgesia.</p>