No abstract

In vivo microdialysis is a technology to measure the concentration of a target substance in extracellular fluid at a localized site by collecting the substance through a dialysis membrane. In the brain, the dialysate enables us to assess real-time changes in neurotransmitters. Therefore, the technique is a useful method for the pharmacological action of central nervous system compounds. In order to fully support researchers, we would like to present an example of the antidepressant evaluation systems using the dialysate from various brain regions in rodents. 【Methods & Results】 A microdialysis probe was inserted into each of the hippocampus or the medial prefrontal cortex (mPFC) in C57BL/6J mice. After 2hour of pre-perfusion, the dialysate was collected at 20-minute intervals at a flow rate of 1µL/min. Then, mice were treated with intraperitoneal injection of R-fluoxetine, a selective serotonin reuptake inhibitor for the treatment of depression, and the dialysate was recollected. The next day, dopamine and serotonin levels were measured by HPLC-ECD. As a result of the study, serotonin release was significantly increased in the hippocampus compared to pre-administration. On the other hand, dopamine release was significantly increased in mPFC compared to pre-administration. 【Conclusions】 In this study, we confirmed the effects of a single antidepressant administration on brain monoamines in wild-type mice. We will continue to introduce a wide range of technologies and evaluation systems to provide value-added preclinical testing services.

Oyster (Crassostrea gigas) contains abundant nutritional elements, including glycogen, vitamine, zinc and taurine. It is reported that oyster extract exhibited several physiological activities．In this study, the symptom relieving effects of oyster extracts on 5-fluorouracil (5-FU) induced toxicity in rats was examined mainly on gastrointestinal toxicity and myelotoxicity.Male SD rats were used in this study. Test groups were as follow, control, 5-FU, 5-FU and oyster extract (200 and 500 mg/kg/days). Oyster extracts were administrated for 21 days in rats. 5-FU was administrated for 5 days after 14 days of oyster extracts administrated. After termination of administration of oyster extracts, recovery period was established for 3 days, and autopsy was performed. No deaths were observed throughout the study period. Regarding body weight and food intake, significant reduction suppression and dose-dependent reduction tendency was observed. In the hematological examination, influence was observed on the white blood cell count, red blood cell count, hemoglobin amount and hematocrit value due to administration of 5-FU. Evaluation of intestinal mucosa by histopathological examination, mucosal thickness, villous height and crypt thickness were dose -dependent or high trend without dose -dependence. In addition, a suppression tendency was also observed for mucosal atrophy of the duodenum due to administration of 5-FU. From the above results, it was suggested that oyster extract is effective in alleviating gastrointestinal toxicity by 5-FU. LBS