Objective:To investigate the protective mechanism of remote ischemic preconditioning (RIPC) on cerebral ischemia-reperfusion (I/R) injury in rats.Methods:Forty-eight SD rats were randomly divided into sham operation group, RIPC group, I/R group, RIPC+I/R group, and compound C group ( n=9 in each group). The neurological function score, cerebral infarction volume (TCC staining) and neuronal apoptosis rate (TUNEL staining) were measured. The activity of superoxide dismutase (SOD) 2 and malondialdehyde level in homogenate of brain tissue were detected. Expression levels of AMP-activated protein kinase (AMPK)/peroxisome proliferator-activated receptor-γ coactivator (PGC)-1α signaling pathway-related proteins in brain tissue were detected by Western blot. Results:The neurological deficit score, cerebral infarction volume and neuron apoptosis rate in the I/R group were significantly higher than those in the sham operation group (all P<0.05). Compared with the I/R group, the neurological deficit score, cerebral infarction volume and neuron apoptosis rate in the RIPC+I/R group were significantly decreased (all P<0.05). Compared with the RIPC+I/R group, the neurological deficit score, cerebral infarction volume and neuron apoptosis rate in the compound C group were significantly increased (all P<0.05). Compared with the sham operation group, the SOD activity in the I/R group was significantly decreased, and the malondialdehyde content was significantly increased (all P<0.05). Compared with the I/R group, the SOD activity in the RIPC+I/R group was significantly increased, and the malondialdehyde content was significantly decreased (all P<0.05). Compared with the RIPC+I/R group, the SOD activity in the compound C group was significantly decreased, and the malondialdehyde content was significantly increased (all P<0.05). Compared with the sham operation group, the expressions of AMPK, p-AMPK, PGC-1α, nuclear respiratory factor (NRF)-1, mitochondrial transcription factor A (TFAM), SOD2, uncoupling protein 2 (UCP2), cytochrome C (CytC), and apoptosis-inducing factor (AIF) in the brain tissue of the I/R group were significantly increased (all P<0.05). Compared with the I/R group, the expressions of AMPK, p-AMPK, PGC-1α, NRF-1, TFAM, SOD2 and UCP2 in the ischemic brain tissue of the RIPC+I/R group were significantly increased, while the expressions of CytC and AIF were significantly decreased (all P<0.05). Compared with the RIPC+I/R group, the expressions of AMPK, p-AMPK, PGC-1α, NRF-1, TFAM, SOD2 and UCP2 in the brain tissue of the compound C group were significantly decreased, while the expressions of CytC and AIF were significantly increased (all P<0.05). Conclusions:RIPC has a protective effect on I/R injury. Its mechanism may be associated with the activation of AMPK/PGC-1α signaling pathway and maintaining mitochondrial biogenesis.

Objective To explore the possible correlation between serum highly sensitive C reactive protein (hs CRP) and blood glucose, insulin, lipids ,insulin sensitivity index (SI),acute insulin response(AIR), and adiponectin in subjects with impaired glucose tolerance (IGT) or newly diagnosed type 2 diabetes mellitus(DM). Methods SI and AIR were assessed by the reduced sample number of Bergman′s minimal model method by intravenous glucose tolerance test in subjects. Meanwhile body mass index (BMI), waist hip ratio (WHR), the serum lipid profile, hs CRP, adiponectin levels were measured. Results Compared with normal control (NC) group[SI(6.6?2.4) 10 -4 (min?mU/L) -1 ,adiponectin7.77(6.35 10.70 mg/L),hs CRP0.40(0.21 1.67mg/L)], the SI and serum adiponectin in IGT group [(1.5?1.1) 10 -4 (min?mU/L) -1 , 4.29(3.59 6.22 mg/L) respectively] and type 2 DM group [(1.5?1.0)?10 -4 (min?mU/L) -1 , 3.46(2.37 4.72 mg/L) respectively] were significantly decreased (all P