摘要
BACKGROUND: The pharmacological action of opioid drugs is related to signal transduction of inhibitory guanine nucleotide binding protein. OBJECTIVE: To quantitatively and qualitatively analyze the influence of morphine on levels of type Ⅱ inhibitory guanine nucleotide binding protein (Gi2 protein) in primary cultured hippocampal neurons at different time points. DESIGN, TIME AND SETTING: A randomized controlled study, which was performed at the Department of Neurobiology, Changzheng Hospital, Second Military Medical University of Chinese PLA between September 2002 and March 2004. MATERIALS: Cerebral hippocampal neurons were obtained from newborn SD rats at 1 2 days of age. Biotin-antibody Ⅱ-avidin fluorescein isothiocyanate (Avidin-FITC) was purchased from Sigma Company (USA) and the Gi2 protein polyclonal antibody from Santa Cruz Biochemistry Company (USA). METHODS: Seven days after culture, mature hippocampal neurons were randomly divided into six groups: 4-, 8-, 16-, 24-, and 48-hour morphine groups, and a blank control group. Neurons in the morphine groups received morphine (10 μ mol/L), which could cause alterations of G-protein mRNA and cAMP expression in the prefrontal cortex. Neurons in the blank control group were given the same volume of saline. MAIN OUTCOME MEASURES: Gi2 protein levels were detected by an immunofluorescence technique, and were analyzed by the image analytic system with the use of green fluorescence intensity. RESULTS: Gi2 protein levels in hippocampal neurons gradually decreased in the 4-, 8-, 16-, 24-, and 48-hour morphine groups. In particular, Gi2 protein levels in the 16-, 24-, and 48-hour morphine groups were significantly lower than that in the blank control group (P 〈 0.05 0.01). CONCLUSION: Morphine may decrease Gi2 protein level in primary hippocampal neurons, and the decreasing trend is positively related to morphine-induced time.
BACKGROUND: The pharmacological action of opioid drugs is related to signal transduction of inhibitory guanine nucleotide binding protein. OBJECTIVE: To quantitatively and qualitatively analyze the influence of morphine on levels of type Ⅱ inhibitory guanine nucleotide binding protein (Gi2 protein) in primary cultured hippocampal neurons at different time points. DESIGN, TIME AND SETTING: A randomized controlled study, which was performed at the Department of Neurobiology, Changzheng Hospital, Second Military Medical University of Chinese PLA between September 2002 and March 2004. MATERIALS: Cerebral hippocampal neurons were obtained from newborn SD rats at 1 2 days of age. Biotin-antibody Ⅱ-avidin fluorescein isothiocyanate (Avidin-FITC) was purchased from Sigma Company (USA) and the Gi2 protein polyclonal antibody from Santa Cruz Biochemistry Company (USA). METHODS: Seven days after culture, mature hippocampal neurons were randomly divided into six groups: 4-, 8-, 16-, 24-, and 48-hour morphine groups, and a blank control group. Neurons in the morphine groups received morphine (10 μ mol/L), which could cause alterations of G-protein mRNA and cAMP expression in the prefrontal cortex. Neurons in the blank control group were given the same volume of saline. MAIN OUTCOME MEASURES: Gi2 protein levels were detected by an immunofluorescence technique, and were analyzed by the image analytic system with the use of green fluorescence intensity. RESULTS: Gi2 protein levels in hippocampal neurons gradually decreased in the 4-, 8-, 16-, 24-, and 48-hour morphine groups. In particular, Gi2 protein levels in the 16-, 24-, and 48-hour morphine groups were significantly lower than that in the blank control group (P 〈 0.05 0.01). CONCLUSION: Morphine may decrease Gi2 protein level in primary hippocampal neurons, and the decreasing trend is positively related to morphine-induced time.