Panax notoginseng saponins inhibits early-stage cell apoptosis in steonecrosis of rabbit femoral head / 西安交通大学学报(医学版)

Objective To investigate the effects of panax notoginseng saponins (PNS) on early-stage apoptosis in steonecrosis of rabbit femoral head .Methods The 24 rabbits were randomly divided into three groups :normal control group ,model group ,and PNS group .In model group ,equine serum (10 mL/kg) and methylprednisolone (40 mg/kg) were injected alternatively to induce osteonecrosis of the femoral head .In PNS group ,PNS (50 mg/kg , i .v .) was administered continuously before methylprednisolone management .In control group ,the rabbits were fed routinely .TUNEL method was used to detect apoptotic cells .Caspase-3 activity in the femoral head was measured by caspase-3 assay kit . Immunohistochemistry method and Western blot analysis were applied to detect the expressions of Bcl-2 and Bax .Results In model group ,typical appearance of apoptotic cells was observed in the femoral head by TUNEL staining (P< 0 .05) .PNS treatment significantly inhibited cell apoptosis of the femoral head in model group .Furthermore ,pretreatment with PNS significantly reversed the inhibition of Bcl-2 expression , augmentation of Bax expression and caspase-3 activity ( P< 0 .05 ) . Conclusion PNS could up-regulate the expression of Bcl-2 ,down-regulate that of Bax ,reduce the activity of caspase-3 ,and inhibit cell apoptosis of the femoral head .

Effects of random food deprivation and refeeding on energy metabolism, behavior and hypothalamic neuropeptide expression in Apodemus chevrieri.

Maintaining adaptive control of behavior and physiology is the main strategy used by animals in responding to changes of food resources. To investigate the effects of random food deprivation (FD) and refeeding on energy metabolism and behavior in Apodemus chevrieri, we acclimated adult males to FD for 4weeks, then refed them ad libitum for 4weeks (FD-Re group). During the period of FD, animals were fed ad libitum for 4 randomly assigned days each week, and deprived of food the other 3days. A control group was fed ad libitum for 8weeks. At 4 and 8weeks we measured body mass, thermogenesis, serum leptin levels, body composition, gastrointestinal tract morphology, behavior and hypothalamic neuropeptide expression. At 4weeks, food intake, gastrointestinal mass, neuropeptide Y (NPY) and agouti-related protein (AgRP) mRNA expressions increased and thermogenesis, leptin levels, pro-opiomelanocortin (POMC) and cocaine- and amphetamine-regulated transcript (CART) expressions decreased in FD compared with controls. FD also showed more resting behavior and less activity than the controls on ad libitum day. There were no differences between FD-Re and controls at 8weeks, indicating significant plasticity. These results suggested that animals can compensate for unpredictable reduction in food availability by increasing food intake and reducing energy expended through thermogenesis and activity. Leptin levels, NPY, AgRP, POMC, and CART mRNA levels may also regulate energy metabolism. Significant plasticity in energy metabolism and behavior was shown by A. chevrieri over a short timescale, allowing them to adapt to food shortages in nutritionally unpredictable environments.

Seasonal changes in body mass, serum leptin levels and hypothalamic neuropeptide gene expression in male Eothenomys olitor.

The present study examined seasonal changes in body mass and energy metabolism in the Chaotung vole (Eothenomys olitor) and the physiological mechanisms underpinning these changes. Seasonal changes in the following parameters were measured in male E. olitor, body mass, food intake, thermogenesis, enzyme activity, masses of tissues and organs, hormone concentrations and expression of hypothalamic arcuate nucleus energy balance genes including neuropeptide Y (NPY), agouti-related protein (AgRP), pro-opiomelanocortin (POMC), and cocaine- and amphetamine-regulated transcript (CART). Body mass was constant over the year, but the masses of tissues and organs differed significantly between seasons. There were significant changes in body fat mass and serum leptin levels over the four seasons. E. olitor showed significant seasonal changes in food intake and thermogenesis, uncoupling protein 1 (UCP1) content, enzyme activity, and serum tri-iodothyronine (T3) and thyroxine (T4) levels. Moreover, mRNA expression in the hypothalamus showed significant seasonal changes. All of our results suggested that E. olitor had constant body mass over the year, which was inconsistent with the prediction of the 'set-point' hypothesis. However, body fat mass and serum leptin levels were significantly different among the four seasons, providing support for the 'set-point' hypothesis. The changes in leptin, NPY, AgRP, POMC, and CART mRNA levels may play a role in the regulation of energy intake in E. olitor. Furthermore, the role of leptin and hypothalamic neuropeptide gene in the regulation of energy metabolism and body mass may be different in animals that are acclimated to different seasons.