No abstract available.
Microdialysis* ; Myocardium*

Microdialysis ; Pharmaceutical Preparations ; metabolism ; Pharmacokinetics

Liver ; metabolism ; physiopathology ; Microdialysis ; methods

OBJECTIVE: In general, it is known that repetitive regular stimuli induce tolerance and repetitive irregular stimuli induce sensitization. We sought to determine the dopamine response in the rat prefrontal cortex under the repetitive regular and repetitive irregular stimuli. METHODS: After giving irregular and regular electrical stimuli repetitively to rats, we measured the dopamine levels of prefrontal cortex. We compared these results with the dopamine levels of prefrontal cortex of rats which were given just one electrical stimulus. Samples were obtained using in vivo brain microdialysis. Dopamine levels in the samples were measured by high pressure liquid chromatography with electrochemical detection. RESULTS: 1) Dopamine levels of prefrontal cortex of both repetitive regular stimuli group and repetitive irregular stimuli group increased after electrical stimuli. 2) Dopamine levels of prefrontal cortex also significantly increased after just one electrical stimulus. 3) Among the repetitive regular stimuli group, repetitive irregular stimuli group and one stimulus group, the dopamine response was most significant in the repetitive irregular stimuli group. CONCLUSIONS: Repetitive irregular electrical stimuli induce sensitization of prefrontal cortex and repetitive regular electrical stimuli don't induce tolerance of prefrontal cortex.
Animals ; Brain ; Chromatography, Liquid ; Dopamine* ; Microdialysis ; Prefrontal Cortex* ; Rats*

Microdialysis (MD), as a living bio-sampling technique, can be utilizable in different tissues,organs or different parts of the same organs, in order to clarify the drug's pharmacokinetics, mechanism, and provide a basis for targeting. This article describes a number of points in recent years, the microdialysis technique in pharmacokinetic studies in the field of application of the status and significant progress.
Animals ; Humans ; Microdialysis ; Pharmaceutical Preparations ; analysis ; Pharmacokinetics ; Tissue Distribution

No abstract available.
Brain Ischemia* ; Glutamic Acid* ; Microdialysis ; Nitric Oxide Synthase* ; Nitric Oxide*

OBJECTIVETo establish the mothod to dectect the microdialysis recovery of HCPT and to investigate the influencing factors, thus to supply experimental basis for in-vivo microdialysis of HCPT.

METHODThe in vitro recovery of HCPT was detected by concentration difference method (increment method and decrement method). The influence of flow rates, medium concentration and temperature on the HCPT recovery and the stability were studied.

RESULTThe recovery detected by increment method was the same as by decrement method. The recovery was independent of HCPT concentrations in the medium. The hydroxycamptothecine recovery had good stability and increased as the temperature rose.

CONCLUSIONMicrodialysis sampling can be used for the pharmacokinetic study of HCPT. Retrodialysis can be used for the determination of the HCPT in vivo recovery.

Camptothecin ; analogs & derivatives ; chemistry ; isolation & purification ; Drug Stability ; Microdialysis ; Temperature

Metabonomics is the branch of systems biology. It has been widely used in the fields of diagnostic markers discovery, disease prognosis, drug action mechanism, drug efficacy and toxicity evaluation, traditional Chinese medicine syndromes differentiation. There are shortcomings in the conventional metabonomics research. Microdialysis technology is a new type of biosampling technology, and metabonomics research based on microdialysis technology is in the ascendant. In view of the particularity of microdialysis technology and its great differences from traditional sampling and pretreatment methods, the metabonomics process based on microdialysis technology has certain similarities with traditional metabonomics research, and its basic process has some particularity. Advantages and basic strategies of metabonomics research by microdialysis technology are systematically summarized for researchers' reference.
Medicine, Chinese Traditional ; Metabolomics ; Microdialysis ; Research Design ; Systems Biology

OBJECTIVETo establish the model of microdialysis, and study the ocular pharmacokinetics of puerarin in anesthetic rabbits.

METHODImplanted the probe into anterior chamber of anesthetic rabbit by surgery. After balanced for 2 h, 1% puerarin eye drop (100 microL) was applied into the cul-de-sac with micropipette. Immediately the dialysate was collected at different time and detected by HPLC with the detection wavelength of 249 nm. The mobile phase was methanol and 0.1% citric acid solution (30:70); the flow rate was 1.0 mL x min(-1).

RESULTAfter the administration, puerarin can be absorbed into aqueous humor quickly. The peak concentration of puerarin appeared at about 1 h and then reduced gradually. The peak concentration(C(max)) is (2.52 +/- 0.31) mg x L(-1). The other lower peak was shown at 3.5 h during the eliminate phase. This might be attributed to the inhibition of aqueous humor production by the puerarin and resulted in a high drug concentration. The area under concentration-time curve (AUC(0-t)) is (5.04 +/- 0.21) mg x h x L(-1) and the eliminate half life (t1/2) is (0.38 +/- 0.13) h.

CONCLUSIONThe microdialysis technique can be used to detect the ocular pharmacokinetics of puerarin, and support the valuable pharmacokinetics parameter for the clinical applications of puerarin eye drop.

Anesthesia ; Animals ; Eye ; metabolism ; Female ; Isoflavones ; pharmacokinetics ; Male ; Microdialysis ; methods ; Ophthalmic Solutions ; Rabbits

To research the pharmacokinetic of Danshensu in brain via microdialysis method and automated blood technique. A microdialysis probe was inserted into the left lateral ventricle, and then dialysate samples and blood samples were continuously collected after iv Danshensu. LC-MS/MS was used to determinate for Danshensu in the dialysate samples. The in vivo recovery was used for the calibration of probe. WinNonlin was used for analyzing all pharmacokinetic data. Pharmacokinetic parameters of DSS in blood and in brain showed that Ke, t1/2,, AUC0-t, MRT were 0.04, 0.018 min(-1), 16.64, 58.76 min, 812.59, 51.19 min x mg x L(-1), 15.28, 79.97 min, respectively. The results were indicated that the study was successfully established LC-MS/MS detection method for Danshensu. Microdialysis combined with automated blood technique could better reflect the dynamic characteristics of Danshensu in the rat brain, and it provides a new perspective for pharmacokinetic study.
Animals ; Brain ; metabolism ; Brain Chemistry ; Lactates ; blood ; pharmacokinetics ; Male ; Microdialysis ; Rats ; Rats, Sprague-Dawley