In Vivo Microdialysis Sampling of Cytokines from Rat Hippocampus: Comparison of Cannula Implantation Procedures

Abstract

Cytokines are signaling proteins that have been of significant importance in the field of immunology, since these proteins affect different cells in the immune system. In addition to their immune system significance, these proteins have recently been referred to as a third chemical communication network within the CNS. The role that cytokines play in orchestrating the immune response within tissues after a mechanical injury leads to potential complications if the source of cytokines (i.e., trauma vs disease) is of interest. Microdialysis sampling has seen wide use in collection of many different solutes within the CNS. Yet, implantation of microdialysis guide cannulas and the probes creates tissue injury. In this study, we compared the differences in cytokine levels in dialysates from 4 mm, 100 kDa molecular weight cutoff (MWCO) polyethersulfone membrane microdialysis probes implanted in the hippocampus of male Sprague− Dawley rats. Comparisons were made between animals that were dialyzed immediately after cannula implantation (day 0), 7 days post cannula implantation (day 7), and repeatedly sampled on day 0 and day 7. Multiplexed bead-based immunoassays were used to quantify CCL2 (MCP-1), CCL3 (MIP-1α), CCL5 (RANTES), CXCL1 (KC/GRO), CXCL2 (MIP-2), IL-1β, IL-6, and IL-10 in dialysates. Differences in cytokine concentrations between the different treatment groups were observed with higher levels of inflammatory cytokines measured in day 7 cannulated animals. Only CCL3 (MIP-1α), CXCL1 (KC/GRO), CXCL2 (MIP-2), and IL-10 were measured above the assay limits of detection for a majority of the dialysates, and their concentrations were typically in the low to high (10−1000) picogram per milliliter range. The work described here lays the groundwork for additional basic research studies with microdialysis sampling of cytokines in rodent CNS.

Bioanalytical chemistry of cytokines – A review

“…The ability to measure multiple cytokines simultaneously is extremely important in a variety of physiological conditions because the concentration fluctuations of one cytokine often induce changes in other networked cytokines. For these reasons, many microdialysis samples from both laboratory animals and humans have used either the multiplexed-bead based assay approach for quantitation or microarrays due to the low microliter sample volume needs combined with multiplexing capability [283–285]. …”

Assessment of Extracellular Cytokines in the Hippocampus of the Awake Behaving Rat Using Large‐Molecule Microdialysis Combined with Multiplex Arrays After Acute and Chronic Ethanol Exposure

“…Though several cytokines were unaffected by probe insertion, there was a distinctive pattern of changes observed in Experiment 1 and replicated again in Experiment 2 that warrants further comment. The issue of tissue damage inherent to cannulation surgery has been raised previously with a technique similar to that used here and yielding similar conclusions (Vasicek et al., ), but empirical studies on this topic are limited. Our findings report somewhat higher baseline levels of response than those shown by Vasicek and colleagues (2013), yet we report less variability across rats and provide a longer time course for a more detailed examination of cytokine changes following probe insertion.…”

Observation of Lidocaine‐suppressed Decrease of Magnesium in Salicylate‐induced Tinnitus with an Online Electrochemical System

“…Basta et al . investigated the direct effect of salicylate application on the spontaneous activity of mouse IC neurons in the brain slices . Wang et al .…”

“…Animals were positioned on a stereotaxic frame. The microdialysis guide cannulas were implanted in the left IC (AP=1.8, ML=2.0, DV=5) according to the subgroups using standard stereotaxic procedures . The guide cannula was kept in place with three skull screws and dental cement.…”