Microdialysis sampling for hepatic metabolism studies. Impact of microdialysis probe design and implantation...

Microdialysis sampling of liver tissue was performed using several probe geometries. The extent of tissue damage and response in vivo caused by implantation and indwelling of the probe was evaluated by histological examination of the tissue. A linear probe, implanted using fused silica tubing, was less damaging than other probe designs and implantation procedures tested. A series of time points up to 48 hr after implantation ere histologically examined. Infiltration of inflammatory cells, predominantly polymorphonuclear leukocytes (PMNs), was evident adjacent to the probe membrane after approximately 8 hr. Mixed inflammatory infiltration, mainly PMNs but including some macrophages, was observed in tissue slices 18 hr after implantation. At 48 hr, the mixed inflammatory infiltration was still present, with some degeneration of PMNs. In implantations of longer than 12 hr, some necrosis appeared at eh implantation site. The rate of delivery of phenol via the probe was stable for at least 30 hr, despite changes in the surrounding tissue.