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AIM: To investigate the effect of hypercapnia on hypoxia-induced pulmonary hypertension and the changes of lysyl oxidase (LOX) and extracellular matrix collagen cross-links in the rat.METHODS: Sprague-Dawley rats were randomly divided into 4 groups: normoxia group, hypoxia group, hypercapnia group and hypoxia+hypercapnia group.LOX activity was detected by fluorescence spectrophotometry.LOX protein expression was detected by immunohistochemistry and Western blot.The mRNA expression of LOX in the pulmonary artery was detected by real-time PCR.RESULTS: The levels of mean pulmonary artery pressure (mPAP), RV/(LV+S) and WA/TA in hypoxia group were significantly higher than those in normoxia group (P<0.01).Moreover, the levels of mPAP and RV/(LV+S) in hypoxia+hypercapnia group were significantly lower than those in hypoxia group (P<0.01).However, no significant difference of mPAP and RV/(LV+S) between hypercapnia group and normoxia group was observed.In hypoxia group, the collagen cross-links in the lung tissue was significantly higher than that in normoxia group and hypercapnia group (P<0.01).Importantly, collagen cross-links in the lung tissue of hypoxia+hypercapnia group was significantly lower than that in hypoxia group (P<0.01).There was no significant difference in collagen cross-links between hypercapnia group and normoxia group.The expression of LOX at mRNA and protein levels and its activity in the pulmonary arteries of hypoxia group were significantly increased as compared with normoxia group (P<0.01).Furthermore, the expression of LOX at mRNA and protein levels and its activity in the pulmonary arteries in hypoxia+hypercapnia group were lower than those in hypoxia group (P<0.01).CONCLUSION: Hypoxia not only up-regulates LOX but also promotes collagen cross-linking in the rat lung, which contributes to the development of pulmonary hypertension.Hypercapnia inhibits hypoxia-induced LOX expression and collagen cross-linking, therefore impairing the progress in hypoxia-induced pulmonary hypertension.
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Objective To observe the effect of sevoflurane and target controlled infusion (TCI)propofol on the oculocardiac reflex (OCR) in patients with paediatrie strabismus surgery.Methods One hundred and thirty-eight patients ASA Ⅰ-Ⅱ undergoing strabismus surgery were randomly allocated to six greups(propofol groups:P_1,P_2,P_3 group; sevoflurane groups:S_1,S_2,S_3 group,23 cases for each) according to target bispectral index (BIS) of 60,50 and 40.In propofol groups continuous infusion of propofolremifentanil [0.2μg/(kg·min)] was adjusted towards target BIS value.The sevoflurane-remffentanil [0.2μg/(kg·min) ] concentration with 50% N2O/O2 was adjusted toward target BIS too.The incidence of OCR and the lowest heart rate(HR) and BIS were recorded.Results The incidence of OCR were 73.9%(17/23),39.1%(9/23),17.4%(4/23),56.5%(13/23),26.1%(6/23),8.7%(2/23)in P_1,P_2,P_3,S_1,S_2,S_3 soup,P_2 and P_3 group were lower than P_1 group,S_2 and S_3 soup were lower than S_1 group,P_3,S_3,S_2,P_2 group were lower than S_1 and P_1 soup,S_1 soup was lower than P_1 group,S_2 soup was lower than P_2 group,S_3 group was lower than P_3 group,there was significant difference(P < 0.05 ).The densities of TCI propofol in P_2 and P_3 soup were higher than that in P_1 group [ (4.3 ±0.2),(5.5±0.1 ) mg/L vs (3.2±0.1 ) mg/L ] (P <0.05),and the densities of sevoflurane in S_2 and S_3 group were higher than that in S_1 group [ ( 1.8±0.3 )%,(2.3±0.2 )% vs(1.3±0.2 )% ] (P<0.05 ).The end-tidal concentration was different with difference of BIS too.Conclusions OCR is relevant to the depth of anesthesia.BIS values of 40-50 seem adequate for the inhibition of OCR.The results suggest that BIS may be a valuable tool during propofol-remifentanil or sevoflurane-remifentanil anesthesia for strabismus surgery in children.The incidence of OCR is higher in propofol than in sevoflurane at the same BIS.
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AIM: To investigate the effect of phosphatidylinositol 3-kinase (PI3K) inhibitor wortmannin on expression of inducible nitric oxide synthase (iNOS) in bronchiole epithelial cells of asthma rat.METHODS: 24 male Sprague-Dawley rats were randomly divided into 3 group, namely control group, asthma group and PI3K inhibitor wortmannin+asthma group. The numbers of total cells and eosinophil cells in bronchoalveolar lavage fluid (BALF) were counted. The expression of inducible nitric oxide synthase was detected by immunohistochemistry method, and iNOS mRNA was detected by reverse transcription-polymerase chain reaction (RT-PCR). The activity of PI3K, iNOS and content of NO in lung homogenates were tested by spectrophotometry.RESULTS: The numbers of eosinophils and the ratios of eosinophils to total cells in BALF in asthma group were significantly higher than those in control group, while those in wortmannin+asthma group were decreased compared to asthma group. The activity of PI3K, iNOS and content of NO in lung homogenats in asthma group were significantly higher than those in control group, while those in wortmannin+asthma group were decreased compared to asthma group. The expression of iNOS protein in bronchiole epithelial cells and mRNA in lung homogenates in asthma group were markedly increased compared to control group, while those in wortmannin+asthma group were decreased compared to asthma group.CONCLUSION: PI3K regulates the expression of iNOS in airway of asthma rat and affects inflammatory reaction in airway.
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AIM: To investigate the effect of roxithromycin on the NF-?B activity,the airway inflammation and bronchial hyperresponsiveness of asthma rats.METHODS: Thirty male adult Sprague-Dawley rats were randomly divided into the control group(Group C,n=10),asthma group(Group A,n=10) and roxithromycin group(Group R,n=10).The asthma model was induced by ovalbumin and Al(OH)3.The airway reactivity was detected and then rats in each group were sacrificed after 24 hours for the last provocation.The concentrations of IL-4,IL-5 and IFN-? in bronchoalveolar lavage fluid(BALF) were measured by ELISA,and the activity of NF-?B protein in bronchial epithelium was detected by immunohistochemistry.RESULTS: Compared with Group C,the airway reactivity in Group A was increased(P
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AIM: To investigate the expression of soluble guanylate cyclase protein and its mRNA in rat pulmonary artery after exposure to hypoxia and hypercapnia. METHODS: Male Sprague-Dawley rats were randomly split into 4 group, which were hypoxic hypercapnic (HH 1 week, HH 2 weeks, HH 4 weeks) group and control group, to copy pulmonary hypertensive animal model. The expression of sGC? 1 and ? 1 subunits protein of medial and small pulmonary artery was performed by immunohistochemistry with a polycolonal antibody. In situ hybridization was performed on the rat lung tissue using sGC oligonuclear probe to assay the expression of sGC? 1 subunit mRNA. RESULTS: The sGC? 1 and ? 1 subunits protein and sGC? 1 subunit mRNA were faint staining in the pulmonary small and medium artery in HH1 week, HH 2 weeks and HH 4 weeks groups compared with control group (all P
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AIM: To study the effect of hypoxia and hypercapnia on nitric oxide (NO) in plasma and superoxide dismutase (SOD), catalase (CAT), soluble guanylate cyclase (sGC), cyclic guanosine monophospholate (cGMP) in lung tissue in rats, and to explore the effect of NO- and H_2O_2-sGC pathway on the development of the pulmonary hypertension. METHODS: The model of hypoxic and hypercapnic 1, 2, 4-week group (HH 1 week, HH 2 weeks, HH 4 weeks) and control group was set up. NO content in plasma, CAT and SOD in rat lung were determined by spectrophotometry. The sGC activity in lung tissue was detected by enzyme kinetic analysis. cGMP content in lung tissue was examined with ~ 125 I-radioimmunoassay. RESULTS: The mean pulmonary artery pressure (mPAP) showed significantly higher in HH 1 week, HH 2 weeks and HH 4 weeks groups compared with control group (all P