OBJECTIVE: The stability of ketamine in biological samples was studied under different storage temperature and time. METHODS: The rabbits were given intragastric administration of ketamine with a dose of 150 mg/kg and were sacrificed after 30 minutes. Blood, liver, kidney and brain of the rabbits were stored at room temperature (between 18 degrees C and 24 degrees C) and -20 degrees C. The specimens were analyzed at different times by GC-MS and GC-NPD. RESULTS: At -20 degrees C, the concentration of ketamine decreased in all of samples (P < 0.05) within 30 days. The concentration of ketamine increased in all of samples stored at room temperature after 5 days(P < 0.05). CONCLUSION The stability of ketamine in biological samples stored at -20 degrees C was better than that at room temperature. The samples suspected containing ketamine should be stored at -20 degrees C and should be tested as soon as possible.
Animals ; Brain/metabolism* ; Cryopreservation ; Disease Models, Animal ; Drug Stability ; Female ; Forensic Toxicology ; Gas Chromatography-Mass Spectrometry/methods* ; Hydrogen-Ion Concentration ; Ketamine/poisoning* ; Kidney/metabolism* ; Liver/metabolism* ; Male ; Rabbits ; Specimen Handling/methods* ; Temperature ; Time Factors

OBJECTIVE: To study the effect of chronic poisoning of ketamine on brain cell apoptosis in adult mouse under different duration and doses. METHODS: The mouse model of chronic poisoning of ketamine was established on adult mouse by tail vein injection of ketamine twice every week with different doses (4, 10, 20 and 30 mg/kg). The mice were sacrificed after continuous injection of ketamine of 1, 2, 4, 8 and 12 weeks. The qualitative assessment of apoptosis was made by transmission electron microscope and the quantitative assessment was made by Caspase-3 immumofluorescence staining method and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) to estimate the time point of apoptosis. All the experimental results were statistically analyzed. RESULTS: The neuron apoptosis was observed in hippocampus and corpus striatum by transmission electron microscope one week after administration, and continued for eight weeks. High level of Caspase-3 expression was observed one week after administration, but with a low level expression after 4 weeks. The number of TUNEL positive cells obviously increased one week after administration and maintained in a high number at 4 weeks. CONCLUSION Ketamine by tail vein injection could induce neuron apoptosis in adult mouse.
Animals ; Apoptosis/drug effects* ; Behavior, Animal/drug effects* ; Brain/pathology* ; Caspase 3/metabolism* ; Disease Models, Animal ; Dose-Response Relationship, Drug ; Female ; Forensic Pathology/methods* ; Hippocampus/pathology* ; In Situ Nick-End Labeling ; Injections, Intravenous ; Ketamine/poisoning* ; Male ; Mice ; Neurons/pathology* ; Time Factors