treadmill 跑步与微透析结合可评估 6-OHDA 损伤大鼠多巴胺能移植后运动功能障碍和改善情况。

Treadmill running combined with microdialysis can evaluate motor deficit and improvement following dopaminergic grafts in 6-OHDA lesioned rats.

机构信息

Department of Orthopedics, Nagoya City University Medical School, Mizuho-ku, Nagoya 467, Japan Department of Physiology, Nagoya City University Medical School, Mizuho-ku, Nagoya 467, Japan.

出版信息

Restor Neurol Neurosci. 1993 Jan 1;6(1):65-72. doi: 10.3233/RNN-1993-6107.

DOI:10.3233/RNN-1993-6107

PMID:21551732

Abstract

To evaluate the physiological role of striatal dopamine (DA) during exercise and the mechanism of functional recovery mediated by grafted DAergic neurons, the locomotor ability (treadmill running) and DA turnover were investigated using treadmill running combined with in vivo microdialysis in the intact control rats, 6-hydroxydopamine (6-OHDA) lesioned rats (hemi-parkinsonian model rats) and DAergic cell grafted rats. The 3 groups of rats were trained to run on a straight treadmill at a speed of 1,800 cm/min for 20 min every day for 7 consecutive days. If the rats could not follow the speed they got electrostimulation (ES) from the grid behind the treadmill belt. The numbers of ES rats received during treadmill running were counted to quantify the locomotor ability. Control rats could keep up with the treadmill easily (0-1 ES/10 min), whereas lesioned rats could not follow the speed (80-100 ES/10 min). Most of the grafted rats received only a few ES, but a few received over 100 ES/10 min. Extracellular DA and its metabolites, dihydroxyphenyl acetic acid (DOPAC) and homovanillic acid (HVA), were measured by in vivo microdialysis and high-performance liquid chromatography (HPLC) during and after treadmill running. In control rats the basal levels of DA, DOPAC and HVA were 2.3 fmol/μl, 1,109.8 fmol/μl and 612.2 fmol/μl, respectively. They increased up to 130%, 140% and 160% by running. In 6-OHDA lesioned rats basal values of DA, DOPAC and HVA were less than 10% of controls. We did not perform microdialysis in these rats since they got too much ES during running. In grafted rats that showed good recovery in locomotor ability, DA returned to almost control level (1.9 fmol/μl), but those of DOPAC (127.8 fmol/μl) and HVA (100.2 fmol/μl) were still low. DA, DOPAC and HVA increased up to 130%, 130% and 150% by running in a similar pattern as in intact rats. These results suggest that grafted neurons can release and metabolize DA in the host striatum both tonically and phasically in relation with internal and external stimuli and also suggest that treadmill running ability is a good indicator of DA turnover in the striatum. Thus, the treadmill running test with microdialysis is useful for quantitative evaluation of motor function in grafted animals.

摘要

为了评估纹状体多巴胺（DA）在运动过程中的生理作用，以及移植 DA 能神经元介导的功能恢复的机制，我们在完整对照大鼠、6-羟多巴胺（6-OHDA）损伤大鼠（半帕金森模型大鼠）和 DA 能细胞移植大鼠中，通过跑步机跑步和体内微透析结合，研究了运动能力（跑步机跑步）和 DA 周转率。3 组大鼠每天以 1800cm/min 的速度在直道跑步机上训练 20 分钟，连续 7 天。如果大鼠跟不上速度，它们会从跑步机皮带后面的网格上接受电刺激（ES）。计数大鼠在跑步机跑步过程中接受的 ES 次数，以量化运动能力。对照大鼠很容易跟上跑步机（0-1ES/10min），而损伤大鼠则无法跟上速度（80-100ES/10min）。大多数移植大鼠只接受了几次 ES，但有少数大鼠接受了 100 多次 ES/10min。通过体内微透析和高效液相色谱（HPLC）在跑步机跑步期间和之后测量细胞外 DA 及其代谢物二羟苯乙酸（DOPAC）和高香草酸（HVA）。在对照大鼠中，DA、DOPAC 和 HVA 的基础水平分别为 2.3fmol/μl、1109.8fmol/μl 和 612.2fmol/μl。跑步后增加了 130%、140%和 160%。在 6-OHDA 损伤大鼠中，DA、DOPAC 和 HVA 的基础值低于对照大鼠的 10%。由于这些大鼠在跑步过程中接受了太多的 ES，我们没有在这些大鼠中进行微透析。在运动能力恢复良好的移植大鼠中，DA 恢复到几乎对照水平（1.9fmol/μl），但 DOPAC（127.8fmol/μl）和 HVA（100.2fmol/μl）仍较低。DA、DOPAC 和 HVA 的增加与完整大鼠相似，达到 130%、130%和 150%。这些结果表明，移植神经元可以在与内部和外部刺激有关的情况下，持续和阶段性地释放和代谢宿主纹状体中的 DA，也表明跑步机跑步能力是纹状体中 DA 周转率的良好指标。因此，结合微透析的跑步机测试对于定量评估移植动物的运动功能是有用的。