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Objective To investigate the effect of neuromuscular electrical stimulation(NMES) on muscle atrophy and muscle fiber type conversion in quadriceps muscles of rats with chronic obstructive pulmonary disease(COPD).Methods Forty-eight male SPF Wistar rats were randomly divided into three groups:the healthy control group,COPD model group and NMES treatment group,with sixteen rats in each group.Rats in the NMES treatment group were given alternating electrical stimulation at 100 Hz and 2 Hz,with each stimulation time of 30 min,7 days per week,for 4 weeks.The control group and the COPD model group were only treated with electrode sheets.After the intervention,the endurance running distance measurement,the pathological changes of rat quadriceps muscle detected by HE staining,the mRNA and protein content of MSTN,MyHC(Myosin Heavy Chain)-Ⅰ,MyHC-Ⅱ a and MyHC-Ⅱ x in quadriceps muscles determined by Realtime PCR and Western Blot were performed.Results Compared with the healthy control group,the cross-sectional area,endurance running distance and MyHC-Ⅰ mRNA and protein expressions in the quadriceps muscles were decreased[(654.7±53.7) μm2 vs.(1079.8±117.2) μm2,(396.7±42.4) m vs.(607.4 ±56.3) m,0.407 ± 0.054 vs.0.997 ± 0.069,0.884 ± 0.102 vs.1.723 ± 0.156,t =4.642,3.785,24.723 and 18.640,P =0.008,0.033,0.000 and 0.000,respectively],while MSTN,MyHC-Ⅱ a and MyHC-Ⅱx mRNA and protein expressions were increased in the COPD model group (all P ＜ 0.01)Compared with COPD model,the cross-sectional area (997.5 ± 92.4 μm2),endurance running distance(597.2±65.8 m)and the expression levels of MyHC-Ⅰ mRNA(0.884±0.097)and protein (1.534±0.182)in the quadriceps muscles were increased(t =3.734,3.602,19.988 and 13.666,P =0.035,0.043,0.000,0.000),and the mRNA and protein expression levels of MSTN,MyHC-Ⅱ a and MyHC-Ⅱ x were decreased in the NMES treatment group(all P ＜0.01).Further correlation analysis found that the protein expression of MSTN in the quadriceps muscles was negatively correlated with muscle cross-sectional area,MyHC-Ⅰ protein levels and endurance running distance(r =-0.724,0.426 and-0.536,P =0.002,0.036 and 0.007,respectively),and positively correlated with the protein expressions of MyHC-Ⅱ a and MyHC-Ⅱ x(r=0.408 and 0.392,P =0.042 and 0.048).Conclusions The expression of MSTN is increased in quadriceps muscle of COPD rats,and NMES can inhibit the expression of MSTN in quadriceps muscles.MSTN is associated with muscle atrophy and muscle fiber conversion in COPD.Inhibition of MSTN expression can improve muscle atrophy and reverse muscle fiber transformation.
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AIM:To investigate the maturation of mice immature myeloid dendritic cells (mDCs) induced by antigen(Ag)85B of mycobacterium tuberculosis, and the expression of TSLPR and OX40L mediated by TSLP in vitro. METHODS:Recombinant mouse GM-CSF ( rmGM-CSF) and rmIL-4 were used to induce bone marrow precursor cells of C57BL/6 mice to differentiate into immature mDCs in vitro.mDCs were identified followed by purification using CD 11c binding magnetic beads .The morphological characteristic of mDCs was observed under inverted phase-contrast microscope and scanning electron microscope .The surface phenotypes of mDCs were determined by flow cytometry .To obtain the opti-mal concentrations of Ag85B and TSLP, immature mDCs were cultured with different concentrations of Ag 85B or TSLP at 0 (control group), 50, 100 and 200 μg/L for 24 h, and the expression of cell surface molecules CD 80, CD86, TSLPR and OX40L was detected by flow cytometry.In addition, the expression of TSLPR and OX40L in Ag85B and TSLP-co-stimula-ted mDCs was determined by flow cytometry .RESULTS:After 7 d of culture in vitro, the cells showed irregular dendritic protrusions under the inverted-phase contrast microscope , and had wrinkles and dendritic splits under scanning electron mi-croscope , conformed to the morphological characteristics of immature mDCs .The mDCs cells expressed higher level of spe-cific marker CD11c, lower level of co-stimulatory molecules CD80 and CD86, which conformed to the phenotype of imma-ture mDCs.The CD80 +and CD86 +cell ratios of mDCs displayed significant increases in 50, 100 and 200μg/L Ag85B or TSLP groups compared with control group (P<0.05).The ratios of TSLPR +and OX40L+cells did not differ among dif-ferent concentrations of Ag 85B groups.The ratios of TSLPR +and OX40L+cells were significantly increased in 100 μg/L and 200μg/L TSLP groups compared with control group and 50μg/L TSLP group (P<0.05).Under the circumstance of optimal Ag85B or TSLP treatment concentration at 200 μg/L, there was significantly decreased in TSLPR and OX 40L cell ratio of mDCs in Ag85B group or Ag85B combined with TSLP group when compared with TSLP group (P<0.05), and no significant difference among Ag85B group, Ag85B combined with TSLP group and control group was observed .CONCLU-SION: Ag85B enhances mDCs maturation by up-regulating the expression of co-stimulatory molecules CD80 and CD86, and inhibit the expression of pro-inflammatory specific molecules TSLPR and OX40L on TSLP-activated mDCs, indicating that Ag85B modifies the development of asthmatic airway inflammation through the pathway of TSLP -activated mDCs.
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The DNA damage, caused by cigarette smoking, can cause airway cell apoptosis and death, which may be associated with the development of chronic obstructive pulmonary disease (COPD). However, just 20%-30% smokers develop COPD, which suggests that different degrees of DNA repair cause different outcomes in smokers. X-ray repair cross-complementing group 1 (XRCC1), a base excision repair protein, has multiple roles in repairing ROS-mediated, basal DNA damage and single-strand DNA breaks. The present study investigated the association between polymorphism in XRCC1 (Arg399Gln) and susceptibility of COPD. A total of 201 COPD cases and 309 controls were recruited and frequency-matched on age and sex. XRCC1 genotype was determined by PCR-restriction fragment length polymorphism analysis. Overall, compared with those with the XRCC1 Arg/Arg genotype, the risk for COPD had no significant difference among individuals with Trp/Trp genotype. However, after stratifying by smoking status, in former smokers, compared with those with the XRCC1 Arg/Arg genotype, the risk for COPD was significantly reduced among individuals with Trp/Trp genotype (adjusted OR=0.22, 95% CI 0.06-0.85, P=0.028); after stratifying by smoking exposure, in light smokers, compared with those with the XRCC1 Arg/Arg genotype, the risk for COPD was significantly reduced among individuals with Arg/Trp genotype and Trp/Trp genotype (adjusted OR=0.39, 95% CI 0.16-0.94, P=0.036; 0.24, 95% CI 0.07-0.79, P=0.019, respectively). In conclusion, XRCC1 Arg194Trp genotype is associated with a reduced risk of developing COPD among former and light smokers.
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Pulsatile blood flow plays an important role in maintaining normal vascular endothelial function. Quantitative measurement of pulsatility of artery blood pressure and blood flow in dogs and effects of enhanced external counterpulsation (EECP) on the pulsatility were taken in this study. Common carotid artery blood pressure and blood flow were measured in 6 beagle dogs that had suffered from an acute myocardial infarction 6 weeks before. A 6F tip transducer catheter was inserted into the right common carotid artery to measure blood pressure, and blood flow was measured in the left common carotid artery by an electromagnetic blood flow probe under anesthesia before and during EECP. Blood pulse pressure, pulsatility index (ratio of peak pressure to end diastolic pressure) and standard deviation of blood pressure were calculated to evaluate the pulsatility of arterial blood pressure. Blood pulse flow, pulsatility index (ratio of peak flow to trough flow) and standard deviation of blood flow were calculated to evaluate the pulsatility of blood flow. Mean vascular resistance (MVR) was calculated as MVR = mean blood pressure/mean blood flow. Blood pulse pressure, pulsatility index and standard deviation of blood pressure were elevated from 30 +/- 9 mmHg, 1.26 +/- 0.05 and 8.7 +/- 2.5 mmHg to 43 +/- 8 mmHg (P < 0.05), 1.54 +/- 0.13 and 12.4 +/- 2.0 mmHg (P < 0.05) before and during EECP, respectively. Blood pulse flow, pulsatility index and standard deviation of blood flow were elevated from 317 +/- 48 ml/min, 2.85 +/- 0.21 and 96 +/- 21 ml/min to 447 +/- 88 ml/min, 4.56 +/- 0.90 and 131 +/- 39 ml/min before and during EECP (P < 0.05). MVR was decreased from 578 +/- 72 before EECP to 476 +/- 85 Wood units during EECP(P < 0.05). These data demonstrate that EECP gives an elevation of pulsatility to blood pressure and blood flow, thus it may lead to the decrease of vascular resistance.
Subject(s)
Animals , Dogs , Blood Pressure , Carotid Arteries , Physiology , Counterpulsation , Hemodynamics , Pulsatile Flow , Regional Blood Flow , Vascular ResistanceABSTRACT
Pulsatile blood flow plays an important role in maintaining normal vascular endothelial function. Quantitative measurement of pulsatility of human arterial blood pressure and the influence of enhanced external counterpulsation (EECP) on the pulsatility were investigated in this study. Eight healthy young male volunteers aged 22 to 35 were included. A 4F tip transducer catheter was inserted under local anaesthesia into the radial artery up to the aortic arch. Intraarterial blood pressure was recorded before and during EECP. Blood pulse pressure, pulsatility index (ratio of peak pressure to end diastolic pressure) and standard deviation of blood pressure in 5 cardiac cycle was calculated to evaluate the pulsatility of arterial blood pressure. The results showed that blood pulse pressure, pulsatility index and standard deviation of blood pressure were elevated from 47 +/- 5 mmHg, 1.64 +/- 0.11 and 13.6 +/- 1.5 mmHg to 77 +/- 3 mmHg, 2.46 +/- 0.25 and 19.3 +/- 2.2 mmHg before and during EECP respectively (P < 0.05). Decreasing of systolic pressure and increasing of diastolic pressure during counterpulsation were also observed. EECP gives an elevation of pulsatility to human blood pressure.
Subject(s)
Adult , Humans , Male , Blood Pressure , Physiology , Blood Pressure Determination , Counterpulsation , Pulsatile FlowABSTRACT
AIM: To investigate the binding characteristics of cholecystokinin receptors in rat pulmonary interstitial macrophages (PIMs). METHODS: The PIMs were isolated from rat lung tissues, purified using the collagenase digestion method combined with alveolar lavage and pulmonary vessel perfusion. The PIM membrane was obtained by supercentrifuge. Receptors for CCK in PIMs were examined using [~3H] labeled CCK-8S as ligand. The specificity of [~3H]-CCK-8S binding to PIMs membrane and the subtypes of CCK receptors were determined by competitive inhibition experiments with CCK-8S, CCK-A and CCK-B receptors selective antagonists (CR1409 and CR2945). The effects of time and incubation temperature on the specific binding were also observed. RESULTS: The specific binding of [~3H]-CCK-8S was not detected in normal rat PIMs, but was detected in the rat administrated with LPS for 48 h. The capacity of ligand-receptor binding was dependent on the incubation temperature and time. Scatchard analysis of the saturation curves suggested that the presence of CCK receptors with high affinity [Kd=(0.68?0.28)mmol/L] and low binding capacity [Bmax=(32.50?2.70) pmol?g~(-1) protein] in PIMs. By means of competitive inhibition studies, the specific binding of [~3H]-CCK-8S to rat PIMs was inhibited by unlabelled CCK-8S [IC_(50)=(3.20?1.13) nmol/L], CCK-AR specific antagonist CR 1 409 [IC_(50)=(0.19?0.06)?mol/L] and CCK-BR specific antagonist CR 2945[IC_(50)=(2.30?0.80)nmol/L]. CONCLUSION: These results suggest the presence of two subtypes of CCK-AR and CCK-BR and provide a structural basis for CCK to play a pivotal role in PIMs.
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AIM: To examine the effect of cholecystokinin-octapeptide (CCK-8) on focal cerebral ischemia/reperfusion injury and its underlying mechanisms. METHODS: By using the suture model of focal cerebral ischemia and reperfusion, the effects of intracerebroventricular (icv) injection of CCK-8 and proglumide, nonselective CCK receptors antagonist, on the infarct size, regional cerebral blood flow (rCBF), and the levels of nitric oxide (NO), malondialdehyde (MDA) were observed in different brain regions of rats subjected to 1 h focal cerebral ischemia followed by 24 h reperfusion. RESULTS: (1) pretreatment with different doses of CCK-8 (0.3 ?g,1.0 ?g,2.0 ?g or 4.0 ?g) could attenuate the infarct size, but the statistically significant effects of CCK-8 were obtained only at the doses of 1.0 ?g and 2.0 ?g(P
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Cholecystokinin(CCK) is one of the first discovered gastrointestinal hormones and one of the most abundant neuropeptides in the brain. CCK , as a neurotransmitter or modulator, is involved in many different biological processes. This review presents an updated overview of the anatomical distribution of CCK in brain, the changes of cerebral CCK gene expression and CCK level during brain injury, the neuroprotective effects of CCK and its underlying mechanisms.