Effects of endurance exercise on synaptic plasticity in cerebral cortex of aged rats and related regulatory mechanism / 中国应用生理学杂志

OBJECTIVE@#To understand and analyze the rules of endurance exercise on the cerebral cortex adaptive mechanism in aged rats.@*METHODS@#In this study, 3-month-old (n=20), 13-month-old (n=24) and 23-month-old (n=24) specific-pathogen free (SPF) male Sprague-Dawley Rat (SD) rats were divided into young (Y-SED), middle-aged (M-SED) and old-aged (O-SED) sedentary control group, and the corresponding Y-EX, M-EX and O-EX in the endurance exercise runner group. The 10-weeks of regular moderate-intensity aerobic exercise intervention were carried out in the endurance exercise runner group. The exercise mode is treadmill exercise (slope 0), and the exercise intensity gradually increases from 60%～65% of the maximum oxygen consumption (V·O) to 70%～75%, and the exercise time is 10 weeks. Hematoxylin and eosin (HE) staining was used to detect age-related morphological changes. The expressions of superoxide dismutase(SOD) and brain-derived neurotrophic factor (BDNF) and the expressions of synapsin 1 (SYN1) and Ca/calmodulin- dependent protein kinases IIα (CaMK IIα) / AMP-activated protein kinase α1(AMPKα1) / mammalian target of rapamycin (mTOR) pathway -related genes were detected.@*RESULTS@#The cerebral cortex structure of the rats in each group showed age-related aging changes, the expression of SOD in the cortex showed a gradual decline, the expression of BDNF showed an age-increasing trend, and the expression levels of SYN1 and CaMK IIα were increased with age. The changes in AMPKα1 and SirT2 and IP3R, AKT1 and mTOR mRNA levels were increased slightly in middle-aged rats and decreased in aged rats. Compared with the rats in each sedentary control group, the nucleus of the cerebral cortex was tightly arranged and the number of nuclei observed under the microscope was increased significantly in each exercise group. Exercise promoted the expressions of SOD, BDNF and synaptophysin SYN1 in the cortex of rats, and the expression levels of SOD and BDNF in aged rats were up-regulated significantly (P＜ 0.01). The expression level of SYN1 in rats was up-regulated significantly (P＜0.05) in the young and aged rats. The expression of CaMK IIα in the cortex of middle-aged and aged rats was up-regulated (P＜0.01), while the expression level of CaMK IIα in young rats was down-regulated (P＜0.01). Exercise could up-regulate the expression level of AMPKα1 in the cortex of young rats (P＜ 0.05), but not in middle-aged and old-age rats. Exercise could up-regulate the expression of SirT2 in the cortex of rats in all age groups (P＜0.05). Exercise up-regulated the expression of phosphoinositide 3-kinase (IP3R)/ protein kinase B 1(AKT1) /mTOR in the cortex of rats, among which young IP3R was significantly up-regulated (P＜0.01) in the young group, mTOR was significantly up-regulated in young and middle-aged group (P＜0.01), and mTOR was also significantly up-regulated in the aged group (P＜0.05).@*CONCLUSION@#Endurance exercise up-regulates BDNF expression, regulates CaMKIIα signaling, activates AMPK signaling pathway and IP3R / AKT1 / mTOR signaling pathway, and improves synaptic plasticity in the cortex.

A cross -sectional study on metabolic syndrome among rural adults / 预防医学

Objective To learn the epidemic characteristics of metabolic syndrome (MS)among rural adults in Changshan County and to provide evidence for developing control and prevention measures.Methods A total of 1 21 2 residents aged over 1 8 years old in four towns were selected by multi -stage stratified cluster random sampling method and an investigation including questionnaire,physical examination and blood biochemical examination was conducted.Results The crude prevalence rate of MS among rural adults in Changshan County was 30.61 % and the standardized prevalence rate was 26.32%.The MS prevalence rate was significantly higher in females than in males (P <0.01 ).The major risk factors for MS were female gender (OR =1 .98),elderly age (OR =1 .02)and family history of hypertension (OR =1 .60). Conclusion The prevalence rate of MS is considerably high in rural areas of Changshan County and effective measures should be taken at early stage.

The effects of eccentric exercise on the skeletal muscle apoptosis and proliferation in rats / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To reveal the effects of three days' repeated exhausted eccentric exercise on the skeletal muscle apoptosis and proliferation in rats.</p><p><b>METHODS</b>Fifty male SD rats aged at 8 week old were randomly divided into control group (C) and training groups (B1, B2, B3, B4) (n = 10), the training groups ran on a treadmill every day till exhausted. After they had been trained repeatedly for three days, their medial head of triceps brachii muscle cell apoptosis was detected in paraffin section by the TUNEL, expression of proliferating cell nuclear antigen (PCNA) protein was examined by immunohistochemistry.</p><p><b>RESULTS</b>(1) The apoptosis appeared sequential change, and it was consistent with the exercise-induced skeletal muscle micro-injury (EIMmI). The apoptosis index in the training group after exercise was much greater than that in the control group (P < 0.05), and it reached the peak at 24 h after exercise, then it reduced at 48 h after exercise. (2) The express of PCNA exhibited a sequential change after exercise, the proliferation index in the training group after exercise was greater than that in the control group (P < 0.05), it increased after exercise immediately, but it reduced at 3 h after exercise, then was reached the peak at 24 h after exercise, the proliferation index was moderately correlated with the apoptosis index (P < 0.05).</p><p><b>CONCLUSION</b>(1) Cell apoptosis can induce the delayed skeletal muscle damage. (2) Apoptosis may be a start factor of skeletal muscle regeneration.</p>

Study of the effects of mild hypothermia on cerebral PO2, PCO2 and pH and body temperature in patients with acute severe head injury / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To study the effects of mild hypothermia on cerebral oxygen partial pressure, carbon dioxide partial pressure, pH and body temperature (PbrO2, PbrCO2, pHbr and BT) in patients with acute severe head injury.</p><p><b>METHODS</b>Thirty-eight patients with acute severe head injury were treated with mild hypothermia, meantime PbrO2, PbrCO2, pHbr and BT were monitored in order to study the changes of PbrO2, PbrCO2, pHbr and BT.</p><p><b>RESULTS</b>In patients with acute head injury, mild hypothermia obviously increased PbrO2, decreased PbrCO2 and CO2 accumulation and acidosis in brain tissue. BT was 1-1.5 deg. higher than rectal temperature (RT) after injury. The BT and RT were decreased when the patients were treated with mild hypothermia, but at the same time the difference between BT and RT was increased.</p><p><b>CONCLUSIONS</b>In patients with acute severe head injury the direct monitoring of PbrO2, PbrCO2, pHbr and BT was safe and reliable, and is helpful in estimating prognosis and mild hypothermia therapy.</p>