To explore heat-reinforcing needling for the metabolite profiling changes in serum of rheumatoid arthritis (RA) rabbits with liquid chromatograph-mass spectrometer (LC-MS) technique, and to investigate its mechanisms.
Forty clean purple blue rabbits were randomized into a normal group, a model group, a reinforcing-reducing needling (RRN) group, a twirling-reinforcing needling (TRN) group, and a heat-reinforcing needling (HRN) group, 8 cases in each group. RA rabbits with cold syndrome were made with ovalbumin and freezing except those in the normal group. No treatment was given in the normal and model groups. The corresponding manipulations for 7 days were applied at "Zusanli" (ST 36) in the three acupuncture groups, 30 min a time, once a day. After intervention the pain threshold and the local skin temperature of each group were observed. Fresh serum from heart was collected for metabonomics detection. Principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA) were adopted. Several metabolites were screened by the variable importance in the projection values (VIP>1) and 
The pain threshold and the local skin temperature in the model group were lower than those in the normal group (both 
The specificity of heat-reinforcing needling for RA presents the regulation for citric acid cycle and glucose metabolism.