OBJECTIVETo 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.

METHODSForty 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) andvalue (<0.05).

RESULTSThe pain threshold and the local skin temperature in the model group were lower than those in the normal group (both<0.05). The pain threshold and the local skin temperature in the three acupuncture groups were higher than those in the model group after intervention (all<0.05), which were better in the HRN group than those in the RRN and TRN groups (all<0.05). The serum metabolites of carnitine, LysoPC (14∶0), LysoPC (18∶3), LysoPE (0∶0/20∶5), LysoPE (0∶0/22∶1), decylic acid, stearic acid and lactic acid in the model group increased compared with those in the normal group, and other metabolites decreased, including leucine, valine, glutamine, pyroglutamic acid, α-ketoglutaric acid, succinic acid, fumaric acid, malic acid, galactose, mannose. Those metabolites were correlated fatty acid, amino acid, citric acid cycle, and glucose metabolism. The metabolites above-mentioned in the three acupuncture groups were regulated in various degrees (all<0.05). Lactic acid decreased and succinic acid, fumaric acid, malic acid, galactose, mannose increased more obviously in the HRN group than those in the RRN and TRN groups.

CONCLUSIONThe specificity of heat-reinforcing needling for RA presents the regulation for citric acid cycle and glucose metabolism.