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ObjectiveTo investigate the effect of Gegen Qinliantang on glucose and lipid metabolism in the rat model of catch-up growth （CUG） induced by a high-fat diet and the underlying mechanism. MethodA total of 60 SD rats were randomized into a normal control group （n=18） and a modeling group （n=42）. The rat model of CUG was established with a restricted diet followed by a high-fat diet， and the changes of general status and body weight were observed. The levels of fasting blood glucose （FBG）， fasting insulin （FINS）， triglyceride （TG）， and total cholesterol （TC） were measured in 6 rats in each group at the end of the 4th and 8th week， respectively. The homeostasis model assessment of insulin resistance index （HOMA-IR） was calculated， and the insulin sensitivity and body composition changes of CUG rats were evaluated. The successfully modeled rats were assigned into 6 groups： normal control， model， high-， medium-， and low-dose Gegen Qinliantang （2.5， 5， 10 g·kg-1）， and pioglitazone （3.125 mg·kg-1）. The rats were administrated with corresponding drugs by gavage for 6 weeks， and the normal control group and model group were administrated with the same amount of normal saline. During the experiment period， the changes of body weight were recorded， and the FBG， FINS， HOMA-IR， TG， and TC were determined at the end of the experiment. Hematoxylin-eosin （HE） staining was employed to observe the pathological changes of skeletal muscle in rats. The levels of reactive oxygen species （ROS） and malondialdehyde （MDA） in the skeletal muscle were measured strictly according to the manuals of the reagent kits. Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） was performed to measure the mRNA levels of silencing information regulator 1 （SIRT1）， peroxisome proliferator-activated receptor-gamma coactivator1α （PGC1α）， and nuclear respiratory factor 1 （Nrf1） in the skeletal muscle. Western blot and immunohistochemistry were employed to assess the expression of SIRT1， PGC1α， and Nrf1 in the skeletal muscle. ResultCompared with the normal control group， the model group presented elevated levels of FBG， FINS， TG， and TC （P<0.05， P<0.01）， increased HOMA-IR （P<0.01）， increased diameter of muscle fibers and adipocytes between muscle cells in the skeletal muscle， rising levels of ROS and MDA in the skeletal muscle （P<0.01）， and down-regulated mRNA and protein levels of SIRT1， PGC1α， and Nrf1 （P<0.05， P<0.01）. Compared with the model group， Gegen Qinliantang （especially the medium and high doses） and pioglitazone decreased the body weight， FINS， HOMA-IR， and TG （P<0.05， P<0.01） and reduced interstitial components such as intermuscular fat in the skeletal muscles and the diameter of muscle fibers. Furthermore， the drugs lowerd the levels of ROS and MDA （P<0.05， P<0.01） and up-regulated the mRNA and protein levels of SIRT1， PGC1α， and Nrf1 （P<0.05， P<0.01） in the skeletal muscle. ConclusionGegen Qinliantang can ameliorate the glucose and lipid metabolism disorders and insulin resistance in CUG rats by regulating the SIRT1/PGC1α/Nrf1 signaling pathway.
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Objective To investigate the expression of peroxisome proliferator?activated receptorγcoactivator?1α(PGC?1α),nuclear respiratory factor 1(NRF?1),mitochondrial transcription factor A(TFAM)and mitochondrial structural and functional alterations under different concentra?tions of ethanol. Methods MTT assay was used to determine the survival rate of AC16 cells under different concentrations of ethanol,and the ap?propriate concentration of ethanol used for subsequent experiments was selected. Mitochondrial membrane potential of AC 16 cells was measured by flow cytometry using fluorescent probe JC?1. The ultrastructural changes of different groups of cells was observed under the electron microscope. The expressions of PGC?1αand its target proteins NRF?1 and TFAM were detected by real?time PCR and Western blotting. Results The number of mitochondrion,mitochondrial membrane potential,and the expressions of PGC?1α,NRF?1,and TFAM were increased in low?concentration eth?anol group(50 mmol/L). While in high?concentration ethanol group(200 mmol/L),they were all decreased,some mitochondria were larger than normal size;the cristae in some mitochondria were disordered,and some mitochondria had no cristae,appearing as circular or elongated vesicles. Conclusion The effect of ethanol on cardiovascular disease is mainly by regulating the expressions of PGC?1αand its downstream proteins NRF?1 and TFAM,which are the key factors in regulating mitochondrial biogenesis.
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Objective To evaluate the changes in the expression of NRF-1 in the spinal cord during remifentail-induced hyperalgesia in a rat model of incisional pain.Methods Forty-eight Sprague-Dawley rats,weighing 180-220 g,were randomly divided into 4 groups (n =12 each) using a random number table:control group (C); incisional pain group (group Ⅰ); remifentanil group (group R); incisional pain + remifentanil group (group Ⅰ + R).All the rats were anesthetized with sevoflurane.A 1-cm longitudinal incision was made through skin,fascia and muscle of the plantar aspect of the right hindpaw in I and I + R groups.In C and I groups,normal saline was subcutaneously infused for 30 min.In group I + R,remifentanil (0.04 mg/kg,0.4ml) was subcutaneously infused for 30 min starting from the onset of skin incision.Paw withdrawal threshold to mechanical stimulation (PWMT) was measured at 24 h before operation and at 2,6,12,24 and 48 h after operation.After measurement of PWMT at 48 h,the rats were sacrificed and L4,5 segments of the spinal cord were removed rapidly to detect the expression of nuclear respiratory factor 1 (NRF-1) by immunofluorescence and Western blot.Results Compared with group C,PWMT was significantly decreased at each time point after operation,and the expression of NRF-1 in the spinal cord was up-regulated in I and I + R groups (P ＜ 0.05).Compared with group I,PWMT was significantly decreased at each time point after operation,and the expression of NRF-1 in the spinal cord was up-regulated in group I + R (P ＜ 0.05).Conclusion Up-regulation of NRF-1 expression in the spinal cord may be involved in the development of remifentail-induced hyperalgesia in a rat model of incisional pain.