Relationship between erythrocyte rheological properties and RBC superoxide dismutase,plasma malondialdehyde level in patients with high altitude polycythemia

AIM:To study the relationship between erythrocyte rheological properties and lipid peroxidation in patients with high altitude polycythemia (HAPC). METHODS:Erythrocyte filtration index (EFI), RBC immune function, RBC superoxide dismutase (RBC-SOD) and plasma malondialdehyde(MDA) in 86 patients with HAPC and 88 healthy subjects at different altitudes (3300 m or 4080 m)were measured. RESULTS:EFI,RBC immune complex flower rate (RBCICFR) and plasma MDA level were increased,RBC-SOD and RBC C₃b receptor flower rate (RBCC₃b RFR )were decreased in patieneswith HAPC.There were masked difference between HAPC patients and healthy subjects. With increasing altitude, EFI, RBCICFR and plasma MDA level in HAPC patients were increased markedly, but RBC-SOD and RBC C₃bRFR were decreased obviously.RBC -SOD was in negativecorrelation with EFI and RBCICFR,and positive correlation with RBCC₃bRFR.Relationship between plasma MDA level and above mentioned para-meters were reversed. CONCLUSION:Lipid peroxidation in patients with HAPC were increased with increasing altitudes, which may be an important cause of decreasing erythrocyte deformability.     

Adaptation characteristics of mitochondria in plateau pikas at different altitudes

AIM: To investigate the adaptive characteristics of mitochondria in plateau pikas at different altitudes. METHODS: According to the altitudes of the capture area, plateau pikas were divided into 4 300 m group (Mado Star Sea, n=6) and 2 900 m group (Laoji Mountain South, n=6). The red blood cells and hemoglobin of the animals in 2 groups were measured. The levels of mitochondrial oxidative phosphorylation (OXPHOS) and fatty acid oxidation (FAO) in the liver and skeletal muscle, and mitochondrial H₂O₂ production level in the skeletal muscle were determined by high-resolution mitochondrial respirometer. RESULTS: The hemoglobin of the plateau pika in 4 300 m group was significantly lower than those in 2 900 m group. The liver state 4 respiration rate of mitochondrial respiratory chain complex I (CI-LEAK), mitochondrial respiratory chain complex I state 3 respiration rate (CI-OXPHOS) and respiratory chain complex I+Ⅱ state 3 respiration rate(CI+Ⅱ-OXPHOS), electron transfer capacity of respiratory chain complex I+Ⅱ (CI+Ⅱ-ETS), the electron transport capacity of the respiratory chain complex Ⅱ (CⅡ-ETS) in 2 900 m group were increased, and the coupling efficiency was decreased compared with 4 300 m group (P<0.05). The skeletal muscle CI-LEAK,CI+Ⅱ-OXPHOS and CI+Ⅱ-ETS were higher than those in 4 300 m group. Mitochondrial state 4 respiration rate with palmitic acid carnitine and malate as substrates (FAO-LEAK) of liver and skeletal muscle in 2 900 m group were increased compared with 4 300 m group. The skeletal muscle with palmitic acid carnitine as a substrate for fatty acid metabolism state 3 respiratory rate (FAO-OXPHOS) was increased in 2 900 m group compared with 4 300 m group. The H₂O₂/O₂ flow ratio (ΔH₂O₂) in 2 900 m group was lower in state 4 respiration rate of mitochondrial respiratory chain complex I (LEAK), state 3 of mitochondrial respiratory chain complex I (OXPHOS), state 3 of mitochondrial respiratory chain complex I+Ⅱ (OXPHOS*) and electron transfer capacity of respiratory chain complex I+Ⅱ (ETS) than 4 300 m group. CONCLUSION: Plateau pikas with different altitudes have different mitochondrial adaptation characteristics.     

生姜叶片发育过程中光合速率与MDA含量及保护酶活性的变化

生姜叶片的叶绿素含量与光合速率随叶龄的增大而升高,１５ｄ时达到最高峰,随后降低。叶片展开后４０ｄ内ＭＤＡ含量比较稳定,ＳＯＤ活性稍有升高,ＰＯＤ、ＣＡＴ活性急剧上升;此后ＭＤＡ含量明显提高,ＳＯＤ活性开始下降,ＰＯＤ、ＣＡＴ活性虽仍继续升高,但上升幅度减小,说明生姜叶片叶龄达４０ｄ时开始趋于衰老。     

Liver protection by Sini decoction in hemorrhagic shock and its mechanism relating to oxygen free radical and nitric oxide

AIM:The work was designed to explore protective effects of a traditional Chinese medicine-sini decoction (SD) on liver in hemorrhagic shock and its mechanism relating to oxygen free radical and nitric oxide.METHODS:Anesthetized Wistar rats were subjected to a hemorrhagic shock protocol for 60 min followed by intravenous injection with normal sodium chloride solution or SD solution. Superoxide dismutase (SOD), malondialdehyde (MDA) and nitric oxide (NO) in liver were examined. The inducible nitric oxide synthase (iNOS) was determined immunohistochemically. RT-polymerase chain reaction (RT-PCR)was used to assay the mRNA, which were corresponding to eNOS (endothelial nitric oxide synthase) and iNOS.RESULTS:The activity of SOD decreased, while the concentration of MDA increased in liver during hemorrhagic shock. SD enhanced SOD activity and inhibited a increase in MDA level in liver (P＜0.01). The NO concentrations in liver in SD group increased at three hours after resuscitation (P<0.01). In addition, it was found that the expression of iNOS was upregulated in sodium chloride-treated group, while SD upregulated the expression of eNOS.CONCLUSION:SD reduces the liver injury caused by oxygen free radicals during hemorrhagic shock. The increasing NO concentration by SD is through upregulation of endothelial NOS expression.     

Apoptosis in heart of multiple organ dysfunction syndrome rats at high altitude

AIM:To study apoptosis in heart of multiple organ dysfunction syndrome (MODS) rat at high altitude. METHODS:The two-hit model of MODS rat was used at two different altitude(1510m, 3900m). Hemorrhage was induced in Wistar rats by catheterizing the femoral artery until a mean arterial pressure was 35 mmHg and maintained for 1 hour. Rususcitation was performed with lactated Ringer's solution at 24 h after hemorrhage, cecal ligation and puncture(CLP) was performed.Then rats were killed at 3 h, 6 h, 12 h and 24 h after CLP, and myocardium sample was excised and stored in liquid nitrogen. Apoptosis in heart was determined by DNA agarose gel electrophoresis, flow cytometry(FCM), transmission electron microscope(TEM) and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling(TUNEL). RESULTS:The special ladder pattern for apoptosis was seen in myocardium sample at high altitude(3 900 m) group.The apoptotic rate in myocardium was higher in high altitude(3 900 m) group than that in lower altitude(1 510 m) group(P<0.01).TUNEL showed that there were positive cells in myocardium in high altitude(3 900 m) group. Apoptotic body was also seen in myocardium in high altitude(3 900 m) group by TEM. CONCLUSION:Apoptosis was induced in myocardium of MODS rats at high altitude, which might play a role in heart failure. The environment of high altitude accelerates the impairment of myocardium in MODS rats.     

Study of lung morphologic features and oxygen free radicals in experimental diabetic rats

AIM:To evaluate the changes of lung morphologic features and oxidative stress in experimental diabetic rats. METHODS: The pulmonary structure of alloxan-induced diabetic rats were quantitatively studied with stereological methods. Changes of ultrastructure, activities of superoxide dismutase (SOD) and contents of malondialdehyde(MDA) of diabetic lung and serum were observed. RESULTS: The volume proportion of alveolar air and mean linear intercept of diabetic rats decreased remarkably in comparison with controls while the volume proportion of alveolar wall, the surface density of alveolar, the numerical density of alveolic area, the numerical density of alveolar and specific surface of alveolar increased significantly. The major change of the type II pneumocyte of diabetic rats was dilation of the rough endoplasmic reticulum (RER). The other findings in diabetic rats had included the presence of thickened alveolar epithelial, pulmonary capillary basal laminae and blood- air barrier, the volume density, the surface density, the mean profile area and the mean perimeter of RER in type Ⅱ pneumocyte of diabetic rats increased remarkably. And the specific surface of RER was significantly lower as compared with controls. SOD activity decreased and MDA content increased significantly in serum of diabetic rats as compared with the control group. SOD activity in the diabetic lung was not different from that of the control lung. However, the content of MDA obviously increased in diabetic lung. CONCLUSION: The morphologic features and oxidative stress in early diabetic rats are abnormal thus the lung should be considered as one of the "target organ"in diabetes mellitus.     

香蕉越冬期间SOD活性和可溶性蛋白质含量的变化

对香蕉和大蕉越冬期间超氧化物歧化酶（SOD）活性和可溶性蛋白质含量变化进行研究,结果表明：越冬前期和中期接受冷锻炼,SOD活性增强,可溶性蛋白质含量增加;越冬后期,香蕉和大蕉受强寒潮影响,发生不同程度的冷害,SOD活性和可溶性蛋白质含量下降。喷施PP333可以提高香蕉SOD活性,增强香蕉的抗冷性。     

Effects of simvastatin on expression of Bcl-2 and Bax in myocardium of rats with renal ischemia-reperfusion injury

AIM: To observe the effect of simvastatin on myocardial tissue after renal ischemia-reperfusion injury and its mechanism. METHODS: A rat model of renal ischemia-reperfusion injury was prepared by clamping the bilateral renal arteries for 45 min. The rats (n=36) were randomly divided into sham operation group, renal ischemia-reperfusion (I/R) group and simvastatin group with 12 rats in each group. The content of serum creatinine (SCr), blood urea nitrogen (BUN) and myocardial tissue malondialdehyde (MDA), the myocardial activity of lactate dehydrogenase (LDH), creatine kinase (CK) and superoxide dismutase (SOD), and the myocardial protein expression of Bcl-2 and Bax were detected. RESULTS: Compared with sham operation group, the content of SCr, BUN and myocardial MDA, and the myocardial activity of LDH and CK in I/R group were significantly increased (P<0.05), and the activity of SOD was significantly decreased (P<0.05). Compared with I/R group, the content of SCr, BUN and myocardial MDA, and the myocardial activity of LDH and CK in simvastatin group were significantly decreased (P<0.05), while SOD activity was enhanced (P<0.05). The protein expression of Bcl-2 and Bax in sham operation group was less than that in I/R group (P<0.05), and the protein level of Bax in simvastatin group was significantly lower than that in I/R group (P<0.05), while the protein level of Bcl-2 was increased (P<0.05). CONCLUSION: Simvastatin has a protective effect on the myocardium of the rats with renal ischemia-reperfusion injury, and the protective mechanism may be related to the elimination of free radicals by simvastatin, increase in the protein expression of Bcl-2 and decrease in the protein expression of Bax.     

Changes of urinary exosomal leucine aminopeptidase and dipeptidyl peptidase 4 in diabetic nephropathy

AIM: To investigate the changes of urinary exosomal enzymes and the correlation with diabetic nephropathy.METHODS: Thirty-four healthy volunteers and 127 patients of type 2 diabetes mellitus (T2DM) were included in the study. The healthy volunteers served as control. The patients with T2DM were divided into 3 groups based on their 24 h urinary albumin/creatinine ratio (UACR): 50 patients with microalbuminuria in early DN group (DN1), 34 patients with macroalbuminuria in overt DN group (DN2) and 43 patients without albuminuria in DM group. The levels of urine exosomal leucine aminopeptidase(exosome-LAP) and exosomal dipeptidyl peptidase 4(exosome-DPP4) were determined by enzyme-linked immunosorbent assay (ELISA). The following methods were used to determine the biochemical parameters: liquid chromatography for glycated hemoglobin (HbA1c), chemical modification method for cholesterol (CH), Jaffe-kinetic assay for creatinine (CR) and urease-GLDH method for blood urea nitrogen (BUN). Multiple stepwise linear regressions were used to analyze the relationship of exosome-LAP or exosome-DPP4 with HbA1c, CH, UACR, CR and BUN. RESULTS: The levels of exosome-LAP and exosome-DPP4 in DM, DN1 and DN2 groups were significantly higher than those in control group (P<0.01). The exosome-LAP in DN2 group was significantly higher than that in DM group. Correlation analysis showed that the levels of urinary exosome-LAP and exosome-DPP4 were positively correlated with HbA1c, CH, UACR, CR and BUN. Multiple stepwise linear regression analysis showed that CH and UACR were independent determinants for exosome-LAP (P<0.01), and UACR and HbA1c were independent determinants for exosome-DPP4 (P<0.01). CONCLUSION: Urine exosome-LAP and exosome-DPP4 are correlated with the severity of diabetic nephropathy. These parameters may serve as clinical markers for the diagnosis and prognosis evaluation of diabetic nephropathy.     

Role of prostaglandins,nitric oxide and potassium channel in the blunting of hypoxic pulmonary vasoconstriction in the high altitude adaptive animal

AIM: To investigate the possible role of prostaglandin, NO and potassium channel in the adaptive blunting of hypoxic pulmonary vasoconstriction (HPV) in high altitude animal (pika). METHODS: The effect of L-NAME, indomethacin and 4-AP on the response of isolated lung strips of pika and Wistar rats instead of pulmonary artery to acute hypoxia were studied. RESULTS: (1) After inhibition of prostaglandins by indomethacin, the percentage increase in hypoxic constriction in lung tissue strip of pikas was greater than that in Wistar rats , P＜0.05; (2) After inhibition of NO synthesis by L-NAME, the percentage increase in hypoxic constriction in lung tissue strip of pikas was greater than that in Wistar rats , P＜0.05; (3) After administration of 4-AP, there was no significant difference in the percentage decrease in hypoxic constriction of lung tissue strip between pika and Wistar rat. CONCLUSIONS: (1) Prostaglandins and NO might modulate HPV in either rat of pika; the closure of Voltage-gated K⁺ channels might mediate HPV in either rat or pika. (2) Prostaglandins and NO might play an important role in the blunting of HPV in pika, Voltage-gated K⁺ channels may play a minor role in the blunting of hypoxic pulmonary vasoconstriction in pika.     

Changes of plasma levels of soluble VEGFR2 and SOD in hypertensive patients and hypertensive diabetic patients

AIM: To explore the changes of plasma levels of soluble vascular endothelial growth factor receptor 2 (sVEGFR2) and superoxide dismutase (SOD) in hypertensive patients and hypertensive diabetic patients. METHODS: In this cross-sectional study, 88 cases were enrolled, which were divided into hypertensive group (n=31), hypertensive diabetic group (n=31) and control group (n=26). Blood pressure was obtained from each participant with mercury sphygmomanometer. The levels of sVEGFR2 and SOD were measured by ELISA. Meanwhile, the levels of plasma glucose, glycosylated hemoglobin A1c (GHbA1c) and lipid profile were detected. RESULTS: The levels of total cholesterol (TC) and body mass index (BMI) were significantly higher in hypertensive group than those in control group (P<0.05). The levels of TC, low-density lipoprotein cholesterol (LDL-C), triglyceride (TG), BMI, waist circumference were significantly higher in hypertensive diabetic group than those in control group (P<0.05). The plasma levels of sVEGFR2 and SOD in both hypertensive diabetic group and hypertensive group were significantly decreased compared with control group (P<0.05), while the mean plasma levels of sVEGFR2 and SOD in hypertensive diabetic group were significantly decreased compared to the hypertensive group (P<0.05). A significantly positive correlation between sVEGFR2 and SOD in the whole study population (P<0.05) was observed. CONCLUSION: The plasma level of sVEGFR2 is decreased in both hypertensive and hypertensive diabetic patients, and more significantly decreased in hypertensive diabetic patients. Decreased SOD level may be associated with to the reduction of sVEGFR2.     

Aluminium-induced effects on growth,morphogenesis and oxidative stress reactions in in vitro cultures of quince

The effects of Al³⁺ [supplied as Al₂(SO₄)₃·18H₂O] addition to culture media (pH 4.0) on growth, morphogenesis (in leaf explants), and oxidative stress reactions in in vitro cultures of ‘BA 29’ quince were investigated. Aluminium (Al 0.5 mM) strongly inhibited shoot growth in the proliferation and rooting phases (Al 2.2 mM), reduced shoot proliferation (Al 1.1 mM), and induced tissue browning. Superoxide dismutase (SOD) activity was increased in shoot cultures supplemented with 2 mM Al. Malondialdehyde (MDA) content of shoots was strongly increased by Al during proliferation (starting from Al 1.7 mM) and rooting (already at Al 1.1 mM), thus serving as a good ‘marker’ for Al toxicity. Even a low concentration of Al (0.5 mM) in the shoot induction medium was found to inhibit shoot regeneration. When standard (Al 0) shoot induction medium was used, leaf explant growth was only reduced by 2.2 mM Al in the subsequent growth phases. Following a preliminary selection for their growth on Al-enriched media, 82 potentially Al-tolerant quince somaclones were selected for further trials.     

不同发育时期板栗叶肉细胞中叶绿体淀粉和质体小球的变化

对板栗在春季折叠的幼叶和平展生长的幼叶、夏季成熟叶和秋季老叶的叶肉细胞中的叶绿体做了透射电镜观察,结果表明,春季折叠的幼叶的叶绿体中不含淀粉和质体小球,平展生长的幼叶含淀粉粒没有质体小球;夏季成熟叶的叶绿体中淀粉最多并出现极少量质体小球;秋季衰老叶的叶绿体中淀粉粒减少直至消失,质体小球数量激增;有的质体小球在叶绿体内被一层膜包围并降解。根据染色特点,可将质体小球分为黑色和灰色2类。淀粉减少及质体小球增多与叶绿体功能衰退相关。     

Changes of adenyl cyclase and phosphodiesterase activities at different time point in hypothalamus of rats with fever and hypothermia

AIM: To observe the changes of adengl cyclase (AC) and phosphodiesterase (PDE) activities of at different time point in hypothalamus of rats with fever and hypothermia. METHODS: Radioisotope method was used to measure the activity of AC and PDE. RESULTS: The fresh yeast caused rats fever after subcutaneous injection 4 h (P<0.01). AC activity reached a peak value at 3rd h after making model (P<0.05), and PDE activity increased slightly in the full process of experiment action; Aminopyrine induced rats hypothermia stat15 min after peritoneal injection (P<0.01). AC activity was higher than normal animal a 15th minute after the injection of aminopyrine. But subsequently AC activity decreased rapidly with the lowest value at 45th minute after the injection (P<0.05). PDE activity fluctuated slightly within normal range in the full course of experiment. CONCLUSION: In fever model, it might be important cause of febrile response that AC activity in hypothalamus increased markedly, while PDE might be the factor causing long-term febrile response. In hypothermia model, the obvious decrease in AC activity indicating that cAMP content in hypothalamus might be related to hypothermia status.     

Changes of ambulatory blood pressure and morphology of resistance vessel in spontaneously hypertensive rats at different weeks of ages

AIM: To observe the changes of ambulatory blood pressure and morphology of resistance vessel in spontaneously hypertensive rats (SHR) at different weeks of ages. METHODS: SHR at the ages of 16-week and 40-week were used. The blood pressure (BP) was monitored by radiotelemetric technique (RTT). The data of BP, diurnal variation and the variability were analyzed. RESULTS: The results showed that the falling rate of BP at night in 16-week group was larger than that in 40-week group (0.0498 vs 0.0211, P<0.05). The BP variability in 40 weeks group was higher than that in 16-week group. Tunica media area/lumen area ratio of arteria mesenterica was increased with aging (P<0.05). CONCLUSION: The variability of 24-hour blood pressure in 40-week-old SHR is higher than that in 16-week-old SHR. Along with the increase in ages, tunica media vasorum area/lumen area in resistance blood vessel (arteria mesenterica) increases.     

Changes in myocardial mitochondrial Ca2＋ concentration and its mechanism in the early stage of severe burn

AIM:To investigate the change in myocardial mitochondrial Ca^2＋ concentration ( [Ca²⁺]_m) and its mechanism in the early stage of severe burn. METHODS:An experimental model of 30%TBSA full-thickness skin scalding was reproduced in rats. [Ca²⁺]_m, cytosolic Ca^2＋ concentration ( _c) and mitochondrial Ca^2＋ transport velocity were determined. RESULTS: ① [Ca²⁺]_m increased evidently at 1st hour postburn, and continuously at 3rd hour, reached the peak at 6th hour postburn, then, it decreased at 12th and 24th hour, but remained in higher level than that of the control. ② There was no significant difference in _c between 1st hour postburn and the control, but _c increased evidently at 3rd, 6th, 12th, 24th hour postburn. ③ mitochondrial Ca^2＋ uptake velocity at 1st hour postburn was higher than that of control, and Ca^2＋ release velocity didn't change obviously, but both of them were decreased at 3rd, 6th, 12th, 24th hour postburn. ④ [Ca²⁺]_m was positive correlated with _c after burn, and negative correlated with mitochondrial Ca^2＋ release velocity at 3rd, 6th, 12th, 24th hour postburn, respectively. CONCLUSION: There was obvious Ca^2＋ overload in myocardial mitochondria after severe burn, the mechanism of which might include ascent of _c and disorder of Ca^2＋ transport in mitochondria.