Implementation of the microdialysis method in the hamster dorsal skinfold chamber

The aim of this study was to implement the midrodialysis method, a well-est ablished technique for measuring the local concentration of neurotransmitte rs and metabolites in the brain, in the dorsal skinfold chamber of the awak e hamster. First, the effects of implanted, nonperfused microdialysis probe s on the microcirculation were examined. Skinfold chambers were prepared wi th and without probes. Two and 3 days later, the following parameters were assessed: diameter, red blood cell (RBC) velocity, macromolecular leakage, leukocyte rolling fraction, and adherent leukocytes in venules, diameter an d macromolecular leakage in arterioles, and functional capillary density (F CD). No significant differences between the animals of the two groups were observed in any of the parameters on either day. Second, the interstitial l actate concentration was measured at two perfusion rates in groups with and without a 4-h tourniquet ischemia. The induction of ischemia resulted in a significant increase in lactate concentration:over the control values in t he tissue within 1 h to 8000+/-860 mu M, where it remained until the reperf usion, at which point the concentration returned to control values within 1 h. The microdialysis method provides the opportunity to measure the concen tration of metabolites in the extravascular space of the hamster dorsal ski nfold chamber.