Comparison of recovery and delivery in vitro for calibration of microdialysis probes

Zhao, Yeping; Liang, Xiaozhong; Lunte, Craig E.

doi:10.1016/0003-2670(95)00379-e

Cited by 54 publications

(31 citation statements)

References 10 publications

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“…The temporal profiles for the loss of tacrine and 9-aminoacridanone were nearly identical after the 9-aminoacridine pretreatment and independent of the collection time after 30 min (data not shown). Since the diffusion of tacrine is likely to be identical regardless of the direction of drug movement across the probe (Zhao et al, 1995), the calculated F value would be expected to be similar to that obtained for the in vivo recovery of tacrine and loss of the retrocalibrator (Bouw and Hammarlund-Udenaes, 1998). The mean F value of 0.79 was used throughout the study to calculate the concentration of tacrine in the ECF from the dialysate concentration.…”

Section: Resultsmentioning

confidence: 59%

Saturable Distribution of Tacrine Into the Striatal Extracellular Fluid of the Rat: Evidence of Involvement of Multiple Organic Cation Transporters in the Transport

Sung¹,

Yu²,

Park³

et al. 2004

Drug Metab Dispos

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ABSTRACT:The kinetics and mechanism by which tacrine is distributed in the rat brain were examined. Tacrine levels in plasma and striatal extracellular fluid were used to evaluate the pharmacokinetics of this process. The K D,brain was decreased with the dose for tacrine, indicating that the distribution to the brain is saturable. The uptake of organic cations such as choline, 1-methyl-4-phenylpyridinium (MPP), tetraethylammonium (TEA), and carnitine was inhibited by the addition of tacrine to cultures of mouse immortalized brain capillary endothelial cells. In addition, the apical to basal transport and basal to apical transport of tacrine were inhibited by the addition of organic cations to cultures of LLC-PK1 cells, suggesting that tacrine transport across the blood-brain barrier (BBB) is mediated by organic cation transport system(s). Consistent with the in vitro results, a standard reverse transcription-polymerase chain reaction procedure was able to amplify the message of mOCT2 and mOCTN2, but not mOCT1, in MBEC4 (mouse brain microvessel endothelial cell line 4) cells. Similarly, mRNAs for rOCT2 and rOCTN2 were present in representative rat brain samples. To determine whether OCT2 and/or OCTN2 transport tacrine, these transporters were cloned and then transfected in SK-HEP1 and HEK 293 cells. The uptake of choline, MPP, and TEA was inhibited by the presence of tacrine in rOCT2-expressing SK-HEP1 cells, whereas the uptake of carnitine was inhibited by the presence of tacrine in rOCTN2-expressing HEK 293 cells. Collectively, these observations suggest that the transport of tacrine across the BBB is mediated, at least in part, by multiple organic cation transport systems in rats.Cholinesterase inhibitors, such as tacrine (Fig. 1A) and donepezil, are clinically useful in the treatment of Alzheimer's disease (Summers et al., 1986;Dooley and Lamb, 2000;Jann et al., 2002). Although these drugs are believed to be pharmacologically active as the result of their ability to stabilize neurotransmitters in the brain (Ogura et al., 2000;Jann et al., 2002), alternate mechanisms, e.g., the inhibition of ␤-amyloid precursor protein secretion, may participate in the enhancement of memory in patients with Alzheimer's disease (Lahiri, 1994).Since the site of action for the cholinesterase inhibitors would be the brain, an understanding of the kinetic process(es) involved in the brain distribution would be essential for therapeutic optimization. Unfortunately, however, only limited literature information is available regarding the neuropharmacokinetics of these cholinesterase inhibitors. For example, in a study involving the administration of radiolabeled tacrine to the rat, the radioactivity associated with the brain was found to be at least comparable to or higher than that found in the plasma (McNally et al., 1989), suggesting that carrier-mediated transport system(s) may be involved in the penetration of tacrine across the BBB. However, since radioactivity does not necessarily represent intact tacrine levels in the plasma a...

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Section: Resultsmentioning

confidence: 59%

Saturable Distribution of Tacrine Into the Striatal Extracellular Fluid of the Rat: Evidence of Involvement of Multiple Organic Cation Transporters in the Transport

Sung¹,

Yu²,

Park³

et al. 2004

Drug Metab Dispos

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show abstract

“…Therefore, to obtain absolute concentrations in interstitial fluid from concentrations in the dialysate, MD probe calibration was assessed by the retrodialysis method (8,11). This method is based on the assumption that the diffusion process is quantitatively equal in both directions through the semipermeable membrane (15). Thus, during retrodialysis, fosfomycin on May 12, 2018 by guest http://aac.asm.org/ was added to the perfusion medium, and the rate of disappearance through the membrane was taken as the in vivo recovery value.…”

mentioning

confidence: 99%

Penetration of Fosfomycin into Inflammatory Lesions in Patients with Cellulitis or Diabetic Foot Syndrome

Legat¹,

Maier

Dittrich

et al. 2003

Antimicrob Agents Chemother

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“…Changes in any of these parameters can have a large influence on the extraction efficiency. Higher flow rates (0.5-2 µL/min) of the perfusate will generally result in lower concentration extraction efficiencies than will lower rates (0.05-0.5 µL/min) (Stenken, 1995;Zhao et al, 1995;Stenken, 1999). If very low flow rates are employed, such as 50 nL/min, equilibrium across the membrane can be achieved, leading to 100% recovery (Menacherry et al, 1992).…”

Section: Recovery/extraction Efficiencymentioning

confidence: 99%

“…Each membrane has a unique set of chemical properties, including the charge and hydrophobicity. Charged membranes can help (or hinder) diffusion of an analyte through the membrane, depending on the coulombic attraction (or repulsion), thus increasing (or decreasing) the recovery of an analyte (Zhao et al, 1995;Sun and Stenken, 2003). Analyte recovery can also be increased by length ening the microdialysis membrane.…”

Section: Recovery/extraction Efficiencymentioning

confidence: 99%

Separation-Based Methods Combined With Microdialysis Sampling for Monitoring Neurotransmitters and Drug Delivery to the Brain

Saylor¹,

Thomas²,

Lunte³

2017

Compendium of in Vivo Monitoring in Real-Time Molecular Neuroscience

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Comparison of recovery and delivery in vitro for calibration of microdialysis probes

Cited by 54 publications

References 10 publications

Saturable Distribution of Tacrine Into the Striatal Extracellular Fluid of the Rat: Evidence of Involvement of Multiple Organic Cation Transporters in the Transport

Saturable Distribution of Tacrine Into the Striatal Extracellular Fluid of the Rat: Evidence of Involvement of Multiple Organic Cation Transporters in the Transport

Penetration of Fosfomycin into Inflammatory Lesions in Patients with Cellulitis or Diabetic Foot Syndrome

Separation-Based Methods Combined With Microdialysis Sampling for Monitoring Neurotransmitters and Drug Delivery to the Brain

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