Addressing feasibility of using microdialysis to monitor adenosine in Arctic ground squirrel (Spermophilus parryii)

Abstract

Both hibernation and anapyrexia are important physiological adaptations. In addition, there is a strong relationship between survival rate and hypothermia during metabolic trauma. Evidence shows that adenosine might be one of the mediators, both of hibernation and anapyrexia. Adenosine is an inhibitory neuromodulator that suppresses neuronal activity when energy stores are low. This inhibitory activity makes adenosine a good candidate for neuroprotection via the suppression of neural activity during metabolic trauma. The main objective of this study was to investigate the feasibility of using microdialysis to monitor extracellular adenosine in the brains of Arctic ground squirrels (AGS), Spermophilus parryii, throughout hibernation. To investigate this feasibility, the basal level of adenosine concentration in AGS was collected using an in vivo microdialysis method. Samples then were analyzed by high performance liquid chromatography (HPLC). Also, the effects of adding an adenosine transporter inhibitor, S-(p-Nitrobenzyl)-6-thioinosine (NBTI), on extracellular adenosine concentration and body temperature (Tb) of AGS were observed. The results of this study indicate that it is not feasible to observe extracellular adenosine concentrations in AGS during hibernation using these techniques.