Objective To observe the changes of renal protein expression after electroacupuncture (EA) of "Taixi" (KI 3) of the Kidney Meridian of Foot-Shaoyin in healthy rats so as to explore the relationship between KI 3 and the Kidney. Methods Twelve adult male Wistar rats were randomly divided into normal control group (n=6) and EA group (n=6). EA (2 Hz/100 Hz

2-4 mA) was applied to bilateral KI 3 for 20 min

once a day for 7 days. Under anesthesia

the rats were perfused transcardiacally with ice saline and their kidneys removed for extracting the total proteins and assaying the differentially expressed proteins with two-dimensional gel electrophoresis (2-DE)

Image MasterTM 2 D Platinum Software and matrix-assisted laser desorption ionization-mass spectrometry (MALDI-MS) MALDI-TOF-MS

respectively. Results Image MasterTM 2 D Platinum Software analysis showed that after EA

9 protein points of the kidney tissues expressed differentially above 3-fold in comparison with control group were upregulated

2 of which were identified to be NAD-dependent isocitrate dehydrogenase and Quinone reductase. No downregulated differentially expressed proteins were found in the kidney tissues. Conclusion EA of "Taixi" (KI 3) can increase the expression of NAD-dependent isocitrate dehydrogenase and Quinone reductase in the kidney tissue

suggesting an increase of energy metabolism after EA and a close correlation between the KI 3 (Source-point) and the Kidney.