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.

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>

Influence of salidroside from Rhodiola Sachalinensis A. Bor on some related indexes of free radical and energy metabolism after exercise in mice / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To study the anti-fatigue mechanism of salidroside from Rhodiola SachalinensisA.Bor (SRS)in anti-oxidation and energy metabolic systems in mice , some related indexes of free radical and energy metabolism after exercise were measured.</p><p><b>METHODS</b>Forty male mice were divided into four groups (n = 10): SRS sport group(SS), SRS quiet group(SQ),sport control group(SC), quiet control group (QC). The mice of SS and SQ groups received SRS solution of 150 ml/kg body weight per day for two weeks, while the mice of SC and QC groups received the same volume of distilled water. 30 min after the last treatment, the mice of SS and SC groups were forced to swim for 120 min without loads. then the biochemical parameters related to fatigue were determined.</p><p><b>RESULT</b>SRS could increase liver superoxide dismutase (SOD) , glutathione peroxidase (GSH-Px) activity of antioxidant enzymes and reduce the malondialdehyde (MDA) content, which might increase the body activity of antioxidant enzymes to play the role of anti-oxidation; SRS had some effect of stabilizing blood sugar, increasing liver glycogen and muscle glycogen reserves, preventing blood sugar, liver glycogen and muscle glycogen levels from reducing in long time exercise on mice; SRS could increase plasma total cholesterol (TC), triglyceride (TG) and free fatty acid (FFA) levels in exercise mice, and it had some effect on metabolism of fat under different conditions, and promoted the use of the role of fat.</p><p><b>CONCLUSION</b>Influence of SRS on some related indexes of free radical and energy metabolism is one of the mechanisms of anti-exercise-induced fatigue of SRS.</p>

The development and application of a continuous passive motion instrument / 中华物理医学与康复杂志

Objective To validate if the continuous passive motion instrument we developed is practical and sta- ble for animal experiment.Methods Ten New Zealand male rabbits were used to establish the animal model of full- thickness defect of articular cartilage in the facies patellaris of femur with their both knees.The rabbits were then randomly divided into groups A and B(10 in each group).The rabbits in group A were administered with CPM of both knees daily for 4 weeks,while those in group B remained normal cage activity only.At the end of the treatment,all the animals were sacrificed,and their articular cartilage was harvested for HE staining and observation.Results It was found that group A had a significantly better repair of the full-thickness defects of articular cartilage than that of the group B,as reflected by the range of motion and morphological observation of the knees(P