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Objective: To explore the association between serum levels of osteopontin (OPN) and systolic pulmonary artery pressure (sPAP) in healthy men following acute high altitude exposure. Methods: According to the inclusion and exclusion criteria, this observational study included 94 male subjects (aged from 18 to 30 years, dwelling in lowland<500 m) who ascended to Litang (4 100 m) from Chongqing (400 m) by bus with a stair-like journey within 7 days in June 2013. Data including basic information, OPN, superoxide dismutase (SOD), and malondialdehyde (MDA) and echocardiographic derived sPAP were collected within 48 hours before ascent and within 2-7 hours after arrival. Accordingly, subjects were divided into 3 groups based on the tertiles of sPAP after acute high altitude exposure: low sPAP group (26.8-32.3 mmHg (1 mmHg=0.133 kPa)) (n=31), middle sPAP group (32.4-37.4 mmHg) (n=32) and high sPAP group (37.5-55.6 mmHg) (n=31). Associations of serum OPN and SOD levels with sPAP were analysed by univariate and multivariate linear regression analysis. Results: After acute high altitude exposure, the levels of sPAP were significantly increased (P<0.001). There were no differences in age, height, weight, body mass index, percent of Han nationality and smoking among 3 subgroups. However, following acute high altitude exposure, the levels of heart rate, systolic and diastolic blood pressure elevated (all P<0.05), whereas the levels of oxygen saturation were reduced in the total subjects and all subgroups (all P<0.05). Moreover, systolic blood pressure of subjects in the high sPAP group was higher than that in low and middle sPAP groups (both P<0.05), and diastolic blood pressure of subjects in high sPAP group was higher than that in low sPAP group (P<0.05). The serum levels of OPN were increased in total cohort(27.9 (22.5,34.0) μg/L vs. 25.6 (18.4, 33.1) μg/L, P<0.05)， and high sPAP group (P<0.05), whereas no differences were found in serum SOD and MDA levels among groups. Furthermore, the serum level of OPN in high sPAP group was higher than that in low sPAP group at high altitude (P<0.05), and there was a trend for decline in SOD level with increasing sPAP (P>0.05). Results from univariable linear regression analysis showed that the serum levels of OPN (r=0.32, P=0.002) and SOD (r=-0.22，P=0.032) were linearly correlated with sPAP in total cohort after high altitude exposure. Multivariate regression analysis showed that the serum levels of OPN(β=0.310，P=0.002) and SOD (β=-0.199，P=0.043) were independently associated with the levels of sPAP at high altitude. Conclusion: After acute high altitude exposure, the serum level of OPN is positively associated with sPAP, suggesting that OPN may be a novel bio-marker for predicting the increase of pulmonary pressure in response to acute high altitude exposure.
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Adolescent , Adult , Humans , Male , Young Adult , Altitude , Blood Pressure Determination , Osteopontin , Pulmonary Artery , SystoleABSTRACT
Objective To investigate the effects on myocardial mitochondria-related indexes in rats after rapid elevation to 3 400 m altitude and myocardial protection effects with metoprolol.Methods Male Wistar rats were randomly divided into three groups with 12 rats in each group as follows,group A(normal group,55 m above sea level),group B(hypoxia group, 3 400 m above sea level),group C(metoprolol group,3 400 m above sea level).Heart rate and blood pressure were measured during the rapid transfer from the plain(Shanghai 55 m)to plateau of 3 400 m.Then,the rats were anesthetized with chloral hydrate.The blood was collected from the abdominal aorta and blood gas indexes were measured.The heart tissue was homog-enized.The oxidativee stress related parameters,such as superoxide dismutase(SOD),malondialdehyde(MDA)and nitric ox-ide(NO)were assayed.The mitochondrial function related parameters,such as complexes-Ⅰ,Ⅱ,Ⅲ,Ⅳ,succinate dehydro-genase(SDH),malate dehydrogenase(MDH)and adenosine triphosphate(ATP)were measured.Results After the rats were exposed to high altitude,the blood oxygen tension and oxygen saturation in the metoprolol group were increased in com-parison with the hypoxia group.Compared with the normal group,the content of MDA in the hypoxia group was increased sig-nificantly,while the content of SOD and NO were decreased significantly(P<0.01),the mitochondrial complex Ⅰ,Ⅱ,Ⅲand Ⅳ were also decreased 44.49%,32.38%,34.43% and 20.16%.Compared with hypoxia group,the MDA was decreased by 13.72%,while SOD and NO were increased by 25.73% and 168.55%,the activity of mitochondrial complexes were also increased by 44.92%,33.73%,37.11% and 10.09% for metoprolol group.The respiratory chain SDH and MDH in hypoxic group were decreased by 29.51% and 42.79% and the activity of Na+-K+-ATPase,Ca2+-Mg2+-ATPase and T-ATPase were decreased by 20.24%,27.56% and 33.32% in comparison with the normal group.After intervention with metoprolol,SDH and MDH were increased by 47.36% and 88.57% separately,the activities of Na+-K+-ATPase,Ca2+-Mg2+-ATPase and T-ATPase were also increased by 31.92%,26.95%,44.93% in comparison with hypoxia group.Those results indicated that metoprolol can increase ATPase activity.Conclusion Under the condition of acute hypoxia at 3 400 m above sea level,myocar-dial injury is related to the changes of oxidative stress and mitochondrial-related enzyme activity.Metoprolol helps to normalize the related indicators and provides the protection for myocardial injury caused by hypoxia.
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Objective To develop a new type of individual first aid kit for plateau conditions to treat acute high altitude reaction.Methods The theories of military preventive medicine as well as the practices of plateau medical protection and treatment were involved in the design and manufacturing of the kit with emphases on kit body architecture design and selection of equipped medicinal materials.Totally 2 100 servicemen had 1 000 ones divided into a control group and 1 100 ones into an observation group.The two groups both underwent conventional treatment,while the observation group applied the kit besides.The incidence rates and curative effects of acute high altitude reaction were compared in the two groups.Results The kit improved first aid of acute high altitude reaction in time consumed and speed.One week after entering the plateau the scores of headache,gastrointestinal symptom,fatigue and dizziness were (1.5±0.5),(1.7±0.4),(1.3±0.6) and (1.6±0.7) respectively in the observation group,and (2.3±0.6),(2.4±0.5),(2.2±0.5) and (2.4±0.6) respectively in the control group.One month after entering the plateau,the observation group had the recovery rate being 99.2％ and the mean therapy time being (8.1±3.3)d,and the control group had the recovery rate being 91.2％ and the mean therapy time being (15.2±6.4)d.The observation group behaved better than the control group in disease grading,therapy time,recovery rate significantly (P＜0.05).Conclusion The kit gains advantages in convenience,portability and curative effect when used to treat acute high altitude reaction,and thus is worthy promoting practically.
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Objective To develop a new type of individual first aid kit for plateau conditions to treat acute high altitude reaction.Methods The theories of military preventive medicine as well as the practices of plateau medical protection and treatment were involved in the design and manufacturing of the kit with emphases on kit body architecture design and selection of equipped medicinal materials.Totally 2 100 servicemen had 1 000 ones divided into a control group and 1 100 ones into an observation group.The two groups both underwent conventional treatment,while the observation group applied the kit besides.The incidence rates and curative effects of acute high altitude reaction were compared in the two groups.Results The kit improved first aid of acute high altitude reaction in time consumed and speed.One week after entering the plateau the scores of headache,gastrointestinal symptom,fatigue and dizziness were (1.5±0.5),(1.7±0.4),(1.3±0.6) and (1.6±0.7) respectively in the observation group,and (2.3±0.6),(2.4±0.5),(2.2±0.5) and (2.4±0.6) respectively in the control group.One month after entering the plateau,the observation group had the recovery rate being 99.2％ and the mean therapy time being (8.1±3.3)d,and the control group had the recovery rate being 91.2％ and the mean therapy time being (15.2±6.4)d.The observation group behaved better than the control group in disease grading,therapy time,recovery rate significantly (P＜0.05).Conclusion The kit gains advantages in convenience,portability and curative effect when used to treat acute high altitude reaction,and thus is worthy promoting practically.
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Objective To investigate the values of echocardiogram for evaluating the changes of left ventricular structure and cardiovascular function of the acute mountain sickness (AMS) patient before and after returning the plain.Methods A total of 33 light AMS patients returning to the plain in time underwent echocardiogram examinations on some cardiovascular indexes before and after returning the plain,including stroke volume (SV),cardiac output (CO),left atrial volume index (LAVI),left ventricular end-diastolic volume (LVEDV),early diastolic mitral flow velocity (E),late diastolic mitral flow velocity (A) and so on.Results The values of heart rate (HR),systolic blood pressure (SBP),diastolic blood pressure (DBP),CO,A and LAVI after going to the plateau were all significantly higher than those before going to the plateau (P＜0.05),while the values of SV,E,E/A and LVEDV were obviously lower (P＜0.05).The values of HR,SBP,DBP,CO,A,E and E/A recovered respectively 1 month after going to the plateau when compared with those before going to the plateau (P＜0.05),while did not restore to the ones before going to the plateau (P＜0.05),and the values of LVEDV,LAVI and SV reached the level before going to the plateau (P＜0.05).The values of LVEDV,SV,SBP,LAVI and E 1 week after returning to the plain came to the level before going to the plateau (P＜0.05),and the values of CO,HR,DBP and A were significantly higher (P＜0.05) while the value of E/A was statistically lower (P＜0.05).Conclusion Echocardiogram can be used to evaluate the left ventricular structure and cardiovascular function of the AMS patient,especially for those light AMS patients in acclimatization period or before and after returning to the plain.
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OBJECTIVE: To investigate the effect of acute exposure to 4300 m altitude environments on the body pathophysiological, serum, TNF-α and IL-1β of Wistar rats and protective effect of methazolamide on Wistar rats. METHODS: Twenty-eight Healthy adult Wistar rats were randomly divided into plain (altitude of 55 m) control group, high altitude (altitude of 4300 m) model group, high altitude methazolamide group, and high altitude acetazolamide group. After being intragastric administration with 0.9% sodium chloride injection, methazolamide (2 times a day, 2.23 mg·kg-1) and acetazolamide (2 times a day, 22.33 mg·kg-1) for 5 consecutive days. The biochemical, blood gas, the pathological results of rats were analyzed. The TNF-α and IL-1β content were detected from the blood samples. RESULTS: Blood and biochemical results showed the high altitude might cause dehydration in rats. Compared with the plain control group, each index of the high altitude model group changed significantly (P<0.01), compared with the high altitude group, the aspartate transaminase (AST), alanine aminotransferase (ALT), pH value, bicarbonate concentration (cHCO3-), buffer base (BB), base excess (BE) of methazolamide and acetazolamide group were significantly decreased (P<0.01), indicated that methazolamide and acetazolamide had protective effect on rat liver.The total protein (TP), urea solution (UREA), partial pressure of carbon dioxide (PaCO2), sodium concentration (cNa+), chloride concentration (cCl-) were significantly increased (P<0.01), indicated that the high altitude group had metabolic acidosis and respiratory alkalosis, and liver and lung tissue had pathological damaged.Compared with the acetazolamide group, the methazolamide group damaged less.Compared with plain control group, serum TNF-α of high altitude groups significantly increased, IL-β of high altitude groups decreased significantly, which, serum TNF-a, IL-1β levels of acetazolamide and methazolamide group were significantly higher than high altitude model group (P<0.01). CONCLUSION: Methazolamide can improve acute high altitude physiological and biochemical status of rats, reduce inflammatory injury, with a good protective effect of hypoxia.
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AIM:This study continuously monitors the hemodynamic changes in conscious and anesthetic rats during rapid ascent to high altitude to investigate whether there is difference between the 2 conditions and discuss the rela-ted underlying mechanism.METHODS: Sprague-Dawley rats were randomly divided into conscious group, anesthetic group, anesthetic-5000-control ( A-5000-control) group, anesthetic-5000-aminoguanidine ( A-5000-AG) group, conscious-5000-control ( C-5000-control ) group and conscious-5000-aminoguanidine ( C-5000-AG ) group.The rats in anesthetic group and conscious group were kept in a hypobaric chamber, in which the simulated altitude was increased from 2 260 m to 5 000 m at 2 m/s, and the rats in other 4 groups were at 5 000 m.The system arterial pressure ( Psa) , central venous pressure ( CVP) , heart rate ( HR) and breathing rate ( BR) were directly and continuously displayed and digitally recorded by a high-performance data acquisition (PowerLab 16/35, AD Instruments) at 200 Hz.RESULTS: The HR and BR in the conscious rats were higher and MAP was lower than those in the anesthetic rats obviously.A significant decrease in mean arterial pressure ( MAP) in conscious and anesthetic groups was observed following the increase in the altitude levels, and the net decrease in MAP in conscious group was significantly greater.Additionally, HR in the conscious rats was sig-nificantly lower at 5 000 m than that of the initial level.The rats in C-5000-AG group and A-5000-AG group showed a sig-nificant increase in the arterial pressure after the intravenous injection of AG, a selective inhibitor of inducible nitric oxide synthase ( iNOS) , and no marked change of HR and BR was found.CONCLUSION: Blood pressure and HR decrease during rapid ascent to high altitude, while the change of BR is not obvious.The mechanisms of self-safety would be trig-gered in the early stage of hypoxia, which activates iNOS and then leads to a larger number of nitric oxide.Plentiful NO di-astolizes the vessels to improve the ventilation-perfusion mismatch and lower the blood pressure.When the altitude arise to 5 000 m, even more earlier, a decompensatory stage may occur in the body, leading to decreased HR and blood pressure further more than those in the anesthetic rats.Due to the effects of pentobarbital sodium, the depression of blood pressure requires a lag period and the net decrease in MAP is less than that in the conscious rats.Therefore, hemodynamic changes during rapid ascent to high altitude in conscious rats are more comprehensive and authentic.