BackgroundEndurance exercise is known to promote a substantial effect on the energy balance in rats and humans. However, little is known about the exact mechanisms for the appetite-suppressive effects of endurance exercise. We hypothesized that endurance training might activate signaling cascades in the hypothalamus known to be involved in leptin signaling.Methods16 male Wistar rats were randomly assigned to two groups: sedentary (n = 8) and exercise groups (n = 8). Animals in the exercise group started treadmill running at 30 m/min, 0% grade, for 1 min/bout. Running time was gradually increased by 2 min/bout every day. The training plan was one bout per day during initial two weeks, and two bouts per day during 3rd-9th week. At the end of nine-week experiment, blood was analyzed for low-density lipoprotein cholesterol (LDL-C), triglyceride (TG), total cholesterol (TC), free fatty acid (FFA), interleukin (IL)-6, and leptin in both groups. Activations of janus kinase 2-signaling transducer and activator of transcription 3 (JAK2-STAT3), protein kinase B (Akt), extracellular regulated kninase (ERKs), and suppressor of cytokine signaling 3 (SOCS3) in hypothalamus were measured in the end of nine weeks of exercise protocol.ResultsNine-week endurance exercise induced lower concentrations of LDL-C, TG, TC, FFA, and leptin in rats (P < 0.05 or P < 0.01). Nine-week endurance exercise significantly increased the circulating IL-6 concentration compared with sedentary group (239.6 ± 37.2 pg/ml vs. 151.8 ± 31.5 pg/ml, P < 0.01). Exercise rats showed significant increases in JAK2, STAT3, Akt, ERKs, and SOCS3 phosphorylations compared with sedentary rats (P < 0.01).ConclusionThe data suggest that endurance exercise is a leptin signaling mimetic in hypothalamus of Wistar rats.

Currently, it is unclear which index of haematological parameters could be used to most easily monitor iron deficiency during endurance training. To address this question, 16 male Wistar rats were randomly assigned to two groups: a sedentary group (n = 8) and an exercised group (n = 8). Initially, animals in the exercise group started running on a treadmill at a rate of 30 m/min, on a 0% grade, for 1 min/session. Running time was gradually increased by 2 min/day. The training plan was one session per day during the initial 2 weeks and two sessions per day during the third to ninth week. At the end of the 9-week experiment, we analysed the blood of the experimental animals for haemoglobin levels, erythrocyte numbers, haematocrit, serum iron levels, total iron binding capacity, transferrin saturation, serum ferritin levels and soluble transferrin receptor (sTfR) levels, and we calculated the ratio of sTfR/ferritin. Erythrocyte numbers, haemoglobin levels and haematocrit values were decreased after 9 weeks of exercise, but sTfR and sTfR/ferritin values were increased (P < 0.01 or P < 0.05). The training regime significantly increased TfR mRNA levels in the bone marrow cells of the exercised rats compared with the sedentary group (1.8 ± 0.5 vs. 1.1 ± 0.2, P < 0.01). These results revealed a significant correlation between TfR levels in the bone marrow cells and the ratio of sTfR/ferritin (r = 0.517; P < 0.01) and sTfR levels (r = 0.206; P < 0.05) in sedentary and exercised rats. In conclusion, we show that sTfR indices and the ratio of sTfR/ferritin could be useful indicators for monitoring iron deficiency during endurance training.

This study aims to investigate the relationship between serum macro- and trace element contents and the degree of disk degeneration in patients with intervertebral disk herniation (IDH). This study was carried out on 69 subjects (30 women and 39 men) diagnosed with IDH. Blood samples of the subjects were collected, and serum concentrations of the elements that include macroelements, such as calcium, phosphorus, potassium, sodium, and magnesium, and trace elements, such as zinc, iron, copper, and selenium, were determined using inductively coupled plasma-atomic emission spectrometry. Magnetic resonance imaging (MRI) examination of the entire lumbar region of the vertebral column was conducted using a 1.5-T MRI scanner. The degree of disk degeneration was classified into three categories. Correlation analysis between the degree of disk degeneration and the serum element was performed using SPSS 16.0. In the correlation analysis between the degree of disk degeneration and the element contents, only calcium was found to be negatively correlated with the degree of disk degeneration (r = -0.332, P < 0.01). Comparison results between male and female groups showed no significant difference in the element content and in the degree of disk degeneration (P > 0.05). Moreover, the serum calcium content showed a significant correlation with the degree of disk degeneration, suggesting that the serum calcium concentration can be used as an indicator of intervertebral disk degeneration prognosis.

Purpose To evaluate the repairment of graphene/β-tricalcium phosphate (G/β-TCP) composite scaffold on cartilage defect in rabbit knee joint. Method The G/β-TCP composite scaffold was prepared and the chemical morphology of G/β-TCP composite was observed by X-ray diffraction (XRD) and scanning electron microscope. The pore size analysis and biomechanical test were performed to test the properties of the material. The composite material containing BMSCs was surgically implanted into the femoral condyle of a full-thickness cartilage defect model in rabbits, and the β-TCP material was used as the control. The visceral tissues of the animals were collected at 2, 4, 8, and 16 weeks, and the pathological changes were observed by HE staining to evaluate the biocompatibility of the material. The G/β-TCP composite material containing BMSCs was implanted into the femoral condyle of rabbit full-thickness cartilage defect model, and β-TCP material was used as control. Creatinine (Cr), alanine aminotransferase (ALT), and C-reactive protein (CRP) were detected by ELISA, and the pathological changes were observed by HE staining. Immunohistochemistry assay was used to detect the expression of type I and II collagen in the transplanted cartilage tissue. Toluidine blue staining was used to observe the growth of cartilage. Results XRD showed that no difference on the X-ray diffraction characteristics was observed between G/β-TCP and β-TCP. The biomechanical test showed that the graphene doped β-TCP material processed higher mechanical strength. Scanning electron microscopy showed that the surface of G/β-TCP material was smoother and the texture was denser. The scaffold combined with BMSCs was transplanted into the full-thickness cartilage defect rabbit model and the results showed that the serum CRP level increased only at 1 month after implantation, and the Cr level increased at 2 months after implantation, while G/β-TCP material showed rare significant pathological changes on the liver, spleen, kidney, brain, and soft tissue around the operation, which indicated a promising biocompatibility. The expression of type I and II collagen in the cartilage tissue of G/β-TCP treated rabbits was dramatically elevated compared to β-TCP at 2 and 3 months after implantation. Conclusion G/β-TCP composite scaffold facilitated the repairment of cartilage defect in rabbit knee joint.