Meiergerd S M, Schenk J O, Sorg B A
Department of Chemistry, Washington State University, Pullman 99164-4630, USA.
Brain Res. 1997 Oct 31;773(1-2):203-7. doi: 10.1016/s0006-8993(97)00926-8.
The effects of repeated footshock stress or cocaine on the kinetics of dopamine clearance in the medial prefrontal cortex (mPFC) were measured by rotating disk electrode voltammetry (RDEV). Five groups of rats were used: animals were either naive (non-handled), pre-treated with five daily saline (1 ml/kg i.p.) or cocaine (15 mg/kg i.p.) injections, or pre-treated with five daily 20-min sessions of sham shock or footshock (0.05 mA/200 ms/s). Dopamine clearance was measured after a 1-week withdrawal period. No difference in Km values was present among the treatment groups, with the mean Km value at approximately 0.5 microM for all groups. However, Vmax values were approximately 50% higher in daily sham shock-, footshock- and cocaine-pre-treated animals compared to naive rats. The increased ability to remove dopamine in these animals suggests that altered dopamine clearance may serve an adaptive mechanism in the mPFC.
通过旋转圆盘电极伏安法（RDEV）测量重复足部电击应激或可卡因对内侧前额叶皮质（mPFC）中多巴胺清除动力学的影响。使用了五组大鼠：动物要么是未处理的（未处理过的），要么预先每天腹腔注射生理盐水（1 ml/kg）或可卡因（15 mg/kg）五次，要么预先每天进行五次20分钟的假电击或足部电击（0.05 mA/200 ms/次）。在1周的撤药期后测量多巴胺清除率。各治疗组之间的Km值没有差异，所有组的平均Km值约为0.5 microM。然而，与未处理的大鼠相比，每天接受假电击、足部电击和可卡因预处理的动物的Vmax值大约高50%。这些动物中多巴胺清除能力的增加表明，多巴胺清除的改变可能是mPFC中的一种适应性机制。
