Serum nitrate and nitrite in dogs with spontaneous cardiac disease

The purpose of this study was to determine whether nitric oxide (NO) concentrations are high in dogs with chronic valvular disease (CVD) and dilated cardiomyopathy (DCM) compared to healthy controls and to determine whether NO concentrations are correlated with type of cardiac disease, disease severity, medical therapy, or serum tumor necrosis factor (TNF) and interleukin-1 (IL-1). Blood was collected from 32 dogs with DCM, from 10 dogs with CVD, and from 10 healthy controls. Indirect determination of NO concentrations was performed by a commercial photoabsorbance assay that uses a Greiss reagent to measure the concentration of nitrite and nitrate (NN), end products of NO metabolism. TNF and IL-1 activities were measured by bioassay. Mean NN concentrations were significantly higher in dogs with heart disease (median, 4.57 microM; range, 0.00-31.05 microM) than in controls (median, 0.00 microM; range, 0.00-6.16 microM; P = .04). NN concentrations in dogs with cardiac disease were not correlated with type or severity of cardiac disease, medication type, or TNF and IL-1 concentrations. NN concentrations were inversely correlated with fractional shortening. The results of this study suggest that metabolites of NO are increased in some dogs with cardiac disease, but these increases appear to be independent of disease severity, TNF and IL-1 concentrations, and type of pharmacologic intervention.     

二乙基己烯雌酚对成年仓鼠睾丸一氧化氮生成和生精细胞凋亡的影响

探讨了在二乙基己烯雌酚（DES）诱发成年动物生精细胞凋亡过程中睾丸一氧化氮（NO）生成和生精细胞一氧化氮合酶（eNOS和iNOs）表达的变化，以期为阐明DES诱发生精细胞凋亡机理的研究提供基础资料。成年雄性仓鼠皮下注射不同剂量DES（分别为0．01、0．1和1mg／kg体重），连续注射7d后取其睾丸，进行NO含量的测定和eNOS、iNOS免疫组化染色。电镜观察生精细胞超微结构的变化，并用TUNEL法检测睾丸中生精细胞凋亡的变化，苏丹Ⅲ染色法检测睾丸生精小管内脂滴分布的变化。结果显示：NO的生成与DES呈剂量依赖性。DES处理后，在1mg／kg体重剂量组，大量生精细胞表达eNOS和iNOS，并出现大量凋亡，退化的生精细胞胞浆内有大量髓样结构，并有大量脂滴分布于生精细胞内和细胞间。eNOS和iNOS阳性生精细胞与凋亡的生精细胞数量和类型基本一致，主要为精母细胞和圆形精子细胞。     

Preliminary experiments on mechanical stretch-induced activation of skeletal muscle satellite cells in vivo

We have shown in vitro that mechanical stretch triggers activation of quiescent satellite cells of skeletal muscle to enter the cell cycle through an intracellular cascade of events including nitric oxide (NO) synthesis that results in the release of hepatocyte growth factor (HGF) from its extracellular association and its subsequent presentation to signaling receptors. In order to explore the activation mechanism in vivo, stretch experiments were conducted in the living animal using our suspension model developed. This system used the weight of the hind portion of rats to stretch the inside muscles of the left hind limb suspended for a period of 0.5–2.0 h. At the end of the stretch period, the rats received an intraperitoneal injection of bromodeoxyuridine followed by immunocytochemistry for its incorporation as an index of satellite cell activation in vivo. Depending on the period of stretch, bromodeoxyuridine labeling was increased significantly over the contralateral unstretched leg or control muscle from untreated rats. A stretched muscle extract prepared from the 2 h stretched tissue by incubating it in PBS, showed the active form of HGF as revealed by immunoblotting and it could stimulate the activation of unstretched satellite cells. Also, administering NO synthase inhibitor L‐NAME prior to muscle stretch abolished the stretch activation of satellite cells. Therefore, the results from these experiments demonstrate that stretching muscle triggers NO synthesis and HGF release, which could activate satellite cells in vivo.     

Influence of transection of the cervical sympathetic trunk on content of NO and expression of NOS in placenta of rats with pregnancy-induced hypertension syndrome

AIM:To observe the influence of transection of the cervical sympathetic track (TCST) on the content of NO and the expression of eNOS mRNA and iNOS mRNA in placenta of the rats with pregnancy-induced hypertension syndrome (PIH).METHODS: Pregnant Wistar rats were randomly divided into 5 groups: control group (C): saline was injected subcutaneously from 14th day to 20th day of gestation;PIH group 1 (H1) and group 2 (H2): L-NAME was respectively injected with 125 mg/kg and 62.5 mg/kg,respectively,then the other procedures were the same as group C;Operation group (O): TCST was operated on 14th day of the gestation,then the other procedures were the same as group H1;sham operation group (S): the cervical sympathetic trunk was only separated and exposed on 14th day of the gestation,then the other procedures were the same as group H1.RESULTS: (1) Except the base value of the BP and protein in urine of the pregnant rats,all the parameters observed in group H1 and H2 were higher than those in group C significantly (P<0.01),and in group H2 were lower than those in group B1 markedly (P<0.01).(2) In comparison with those in group C,the size and body weigh of fetus in group H1,H2 decreased markedly (P<0.01).The above indexes in group H1 were lower than those in group H2 markedly (P<0.01,P<0.05).The changes of the rate of embryo absorption and fetal death,and deformity rate of the fetal rats were contrary to the above indexes.(3) The content of NO and the expression of eNOS mRNA and iNOS mRNA in placenta in group H1 and H2 were lower than those in group C markedly (P<0.01).Those in group H1 were lower than those in group H2 obviously (P<0.01,P<0.05).Those in group O were higher than those in group H1 markedly (P<0.01).CONCLUSION: TCST protects pregnant rats against PIH,and it was related to the mRNA expression of eNOS and iNOS and the content of NO in placenta tissue.     

温度和GA_3对桃果实采后乙烯合成及桃ETR1同源基因表达的影响

为明确桃果实采后成熟衰老期间乙烯的合成与桃ETR1同源基因之间的关系,进一步了解乙烯的转导和作用过程,设计合成了桃ETR1扩增引物RTetr1和RTetr2,用RT-PCR方法研究了温度和GA3处理对白凤桃(Amyg-daluspersicaL.)果实采后乙烯生成和桃ETR1同源基因表达的影响。结果表明,低温处理降低了果实乙烯释放量,低温+GA3处理不仅降低了果实乙烯释放量,还延缓乙烯释放高峰期。PCR分析表明,桃ETR1的cDNA合成受温度和GA3调节,随着乙烯合成能力的增强,ETR1同源基因的表达水平增加,在乙烯信号转导过程中呈正向表达模式。     

Induction of antiviral resistance and stimulary effect by oligochitosan in tobacco

Oligochitosan was applied by spraying it on tobacco leaves for inhibition of tobacco mosaic virus (TMV). The maximum inhibition of TMV by oligochitosan was observed when inoculation occurred at 24 h after spraying 50 μg ml⁻¹ oligochitosan. The production of H₂O₂ and NO in epidermal tobacco cells induced by oligochitosan was investigated by epidermal strip bioassay and LSCM, using cell permeable fluorophore diaminofluorescein diacetate (DAF-2D) and 2′,7′-dichlorofluorescin diacetate (H₂DCF-DA), respectively. Epidermal tobacco cells treated with oligochitosan resulted in a strong increase of intracellular NO and H₂O₂. Oligochitosan and NO donor sodium nitroprusside (SNP) induced the defense reaction against tobacco mosaic virus (TMV), and increased phenylalanine ammonia-lyase (PAL) activity. Co-treatment of the tobacco cells with oligochitosan and NO scavenger CPTIO blocked the inducing resistance. The results indicated that the defense response induced by oligochitosan was connected with NO pathway.     

乙酰水杨酸调控猕猴桃果实后熟软化进程中的Ad-EXP1基因表达

以布鲁诺猕猴桃(Actinidia deliciosa cv.Bruno)成熟果实为材料,根据植物α-expansin(EXP)基因的氨基酸保守序列设计简并引物,利用RT-PCR方法结合3’RACE扩增得到1个长为957bp的cDNA片段(Ad-EXP1)。该基因片段编码211个氨基酸,与其它植物该基因核苷酸同源性为59%～85%,氨基酸同源性为73%～91%。Northern杂交结果表明,Ad-EXP1基因在采收当天的果实中表达很弱,随着果实成熟衰老进程加快趋于增强;乙酰水杨酸(ASA)处理延缓果实后熟软化和乙烯生成,也显著抑制Ad-EXP1基因表达。鉴于Ad-EXP1表达丰度与乙烯生成、果实软化程度的一致性,推测该基因在猕猴桃果实后熟软化进程中起着重要作用。     

Renoprotective effects of sesamin on renal hypertensive and hyperlipidemic rats

AIM: To investigate the effects of sesamin on progression of renal injury in renal hypertensive and hyperlipidemic rats (RHHR). METHODS: RHHR was induced by 2K1C and high lipid baitvessel. After 7 weeks of intragastric administration with sesamin, the contents of serum creatinine (Scr), blood urea nitrogen (BUN), 24 h urinary protein excretion (UPE) were measured. In addition, the activity of total antioxidative capacity (T-AOC), superoxide dismutase (SOD), the concentrations of malondialdehyde (MDA), hydrogen peroxide (H2O2), and the nitric oxide synthase (NOS) and nitric oxide (NO) levels in renal homogenate were measured. RESULTS: Compared with the model group, seasamin (in 100 mg·kg-1 and 33 mg·kg-1 groups) evidently decreased the contents of Scr, BUN, UP and the concentration of MDA, iNOS, H2O2 in renal tissure. It also improved the levels of NO, cNOS and activity of SOD, T-AOC in renal tissure. CONCLUSION: Sesamin ameliorates hypertensive and hyperlipidemic-induced renal injury, probably by enhancing antioxidative activity, scavenging hydroxyl radical and restraining iNOS level.