ABSTRACT
OBJECTIVE: To observe the effect of chronic unpredicted sequence of mild stress on the expression of cAMP-dependent protein kinase A(PKA) and phosphorylated cAMP-responsive element binding protein (P-CREB) in hippocampus of rats and the antagonism of antidepressors (fluoxetine). METHODS: Thirty-six male Sprague Dawley rats were randomly and equally allocated to 3 groups: A normal control group, a model group, and a fluoxetine group. All rats except the control group were singly housed and exposed to an unpredicted sequence of mild stressors. The different distribution and expression of PKA and P-CREB in the hippocampus of rats in different groups were investigated with immunohistochemistry and Westernblot technique. RESULTS: The positive PKA and P-CREB cells in the hippocampus of normal controls were the pyramidal cells and the granule cells. The PKA and P-CREB protein expression levels in the hippocampus of model rats were significantly lower than those of the normal controls (P<0.05). The PKA and P-CREB protein expression levels in the hippocampus of the fluoxetine group were significantly higher than those of the model group (P<0.05). CONCLUSION: Chronic unpredicted mild stress can affect the PKA and P-CREB expression in hippocampus of rats and fluoxetine has antagonism against it.
Subject(s)
Cyclic AMP Response Element-Binding Protein/biosynthesis , Cyclic AMP-Dependent Protein Kinases/biosynthesis , Depression/metabolism , Fluoxetine/antagonists & inhibitors , Hippocampus/metabolism , Animals , Antidepressive Agents, Second-Generation/antagonists & inhibitors , Cyclic AMP Response Element-Binding Protein/genetics , Cyclic AMP-Dependent Protein Kinases/genetics , Depression/etiology , Male , Random Allocation , Rats , Rats, Sprague-Dawley , Stress, Physiological/metabolismABSTRACT
OBJECTIVE: To explore the effects of baisong tablets on the behavior and contents of norepinephrine and dopamine in the brain of stress rats. METHODS: Forty adult Sprague-Dawley male rats were randomly divided into 4 groups: the control group, the depression model group, the baisong tablet group and the fluoxetine group. The depression model was replicated by chronic unpredictable mild stress and single house in 21 days. Ten rats as a group were treated with baisong tablets or fluoxetine hydrochloride. Changes of behaviors were observed by open-field test and the volume of sugar-solution the rat drank in 24 hours. The weight increase was also observed. The levels of norepinephrine and dopamine in the brain in each group were detected with high-pergomance liquid chromatography. RESULTS: Compared with the model group, baisong tablets could improve the depressive behaviors significantly, and increase the levels of norepinephrine and dopamine in the rat brain. CONCLUSION: Baisong tablets can improve the depressive behaviors and increase the levels of 5-hydroxytryptaimne and dopamine in the brain of stress rats.
