microdialysis probe enables the study of the concentration of analytes in the bile in awake animals where the bile flow is intact (1-3). A diagram of the shunt microdialysis probe is shown in F1. The probe’s shunt, which carries the bile flow, is of appropriate dimensions for implantation into the bile duct of an adult rat. Suspended inside the shunt is a linear microdialysis probe that continu...

Using in vivo microdialysis, we measured hippocampal extracellular glucose concentrations in rats while they performed spontaneous alternation tests of spatial working memory in one of two mazes. Extracellular glucose levels in the hippocampus decreased by 32% below baseline during the test period on the more complex maze, but by a maximum of 11% on the less complex maze. Comparable decreases w...

fundamentally important to the brain in physiology and clinical pathologies, such as ischemia and hypoxia. The degree of interrelation of these compounds extends beyond physiology. This is illustrated by the fact that all three compounds are regularly assayed by the electrochemical measurement of H202, the product of the reaction of each of these compounds with their respective oxidase enzyme (...

Cerebral microdialysis is a chemical detection method capable of identifying and simultaneously sampling a wide range of substances in the micromilieu of the monitoring probe. The interstitial space of biological tissues and fluids is sampled through a thin fenestrated dialysis catheter inserted into the brain. The technique has been reported in patients with Parkinson's disease. However, the p...

The eye presents unique challenges in both the development of tools for elucidating drug disposition as well as for the development of modes of drug delivery for treatment of ocular diseases. In this paper, we present a discussion of the anatomical and physiological characteristics and limitations present in the eye for microdialysis sampling of endogenous substrates and xenobiotics. To date, o...

BACKGROUND Uremic toxins are typically measured in plasma and little is known of their interstitial concentrations. We undertook experiments to validate a microdialysis technique for simultaneous recovery of small and large uremic toxins in the subcutaneous interstitial fluid (ISF). METHODS Microdialysis catheters were inserted into the subcutaneous interstitium of 8 subjects (controls and ur...

Chip-level integration of microdialysis membranes is described using a novel method for in situ photopatterning of porous polymer features. Rapid and inexpensive fabrication of nanoporous microdialysis membranes in microchips is achieved using a phase separation polymerization technique with a shaped UV laser beam. By controlling the phase separation process, the molecular weight cutoffs of the...

The optimisation and evaluation of the microdialysis component of a prototype miniaturised total analysis system for application in the continuous monitoring of lactate and glucose is reported. The complete unit comprises a high efficiency microdialysis sampling system, a miniaturised microflow manifold with an integrated biosensor array, together with the hardware and software necessary for co...

Changes in the microenvironment are important in the development of cancer and further tumor growth. Although landmark discoveries have been made regarding genetic alterations in cancer at a cellular level very little is known about protein regulation in the extracellular space. In the microenvironment many growth factors are activated at a post-translational level by interactions of different ...

An on-line microdialysis/high-performance liquid chromatography method was developed for the simultaneous determination of melamine and cyanuric acid in non-dairy coffee creamer. To collect these analytes from aqueous samples, the microdialysis system featured a microdialysis probe incorporating a polyarylethersulfone membrane and employed 0.05 M HCl in 0.1% (v/v) MeOH as the perfusate, with o...