Effect of 4-chloro-2-methylphenoxyacetic acid and 2,4-dimethylphenol on human erythrocytes

The effects of exposure of human erythrocytes to different concentrations of 4-chloro-2-methylphenoxyacetic acid (MCPA) and its metabolite—2,4-dimethylphenol (2,4-DMP) were studied. The investigations concerned mainly the content of glutathione (GSH and GSSG), glutathione peroxidase (GSH-Px), glutathione transferase (GST), and the level of adenine energy charge (AEC). Reactive oxygen species (ROS) such as hydroxyl radical, superoxide anion, hydrogen peroxide, and nitric oxide are produced during normal processes in the cell. Under normal conditions, antioxidant systems of the cell minimize damage caused by ROS. When ROS generation increases to an extent that it overcomes the cellular antioxidant systems, the result is oxidative stress. We observed that MCPA and 2,4-DMP decreased the level of GSH in erythrocytes in comparison with control. MCPA did not affect glutathione peroxidase and glutathione transferase activity, while 2,4-DMP increased their activity. 2,4-DMP decreased the level of ATP and increased the content of ADP and AMP, leading to the fall of the level of AEC. MCPA and 2,4-DMP transform hemoglobin into methemoglobin, thus preventing oxygen transport. Comparison of the toxicity of MCPA and 2,4-DMP revealed that the most prominent changes occurred in human erythrocytes incubated with 2,4-DMP.     

Effects of water‐misting sprays with forced ventilation on post mortem glycolysis,AMP‐activated protein kinase and meat quality of broilers after transport during summer

Effects of water‐misting sprays with forced ventilation on post mortem glycolysis, adenosine monophosphate‐activated protein kinase (AMPK) and meat quality of broilers after transport during summer were investigated in the present paper. A total of 105 mixed‐sex Arbor Acres broilers were divided into three treatment groups: (i) 45 min transport without rest (T); (ii) 45 min transport with 1 h rest (TR); and (iii) 45 min transport with 15 min water‐misting sprays with forced ventilation and 45 min rest (TWFR). Each treatment consisted of five replicates with seven birds each. The results indicated that the water‐misting sprays with forced ventilation could mitigate the stress caused by transport under high temperature conditions during summer, which reduced the energy depletion in post mortem Pectoralis major (PM) muscle. This resulted in a higher energy status compared to the T group, which would decrease the expression of phosphorylation of AMPK (p‐AMPK). Furthermore, decreased the expression of p‐AMPK then slowed down the rate of glycolysis in post mortem PM muscle during the early post mortem period, which in turn lessened the negative effects caused by transport on meat quality. In conclusion, water‐misting sprays with forced ventilation may be a better method to control the incidence of the pale, soft and exudative meat in broilers.     

盐碱胁迫下产ACC脱氨酶促生菌对绿豆叶片脂质代谢的影响

为探讨盐碱胁迫下产ACC脱氨酶促生菌对绿豆叶片脂质代谢的影响,采用液相色谱质谱联用技术分析盐碱胁迫下接种产ACC脱氨酶促生菌（DQJC1）后绿豆叶片内脂类代谢产物的变化。结果表明：盐碱胁迫下接种DQJC1可以促进绿豆生长,显著提高了绿豆植株的株高（34.87%）、地上部鲜质量和干质量（44.07%和46.43%）、地下部鲜质量和干质量（30.56%和23.68%）及叶绿素含量（41.61%）。同时在绿豆叶片中共筛选到61个具有显著性差异的代谢产物,其中包括32种甘油磷脂类、14种固醇类、4种甘油糖脂类、3种鞘脂类和8种其他脂类;其中上调的代谢物主要为甘油磷脂（PC、PG、LPC、PI、PE、LPG）、甘油糖脂（SQDG47∶11）及鞘脂（CerG1d18∶2/16∶0+O）,下调的代谢物主要为固醇（TG）,甘油糖脂（SQDG：16∶0/16∶0）及鞘脂（CerG1d34∶2+O）。KEGG通路富集分析发现筛选出的差异代谢物中有6种代谢物被富集到9条代谢通路中,包括甘油磷脂代谢通路、甘油脂代谢通路、自噬性溶酶体代谢通路、糖基磷脂酰肌醇代谢通路、醚脂质代谢通路、亚油酸代谢通路、磷脂酰肌醇代谢通路、α-亚油酸代谢通路和花生四烯酸代谢通路。     

Effects of modulatory agents on neurally-mediated responses of trout intestinal smooth musclein vitro

Mediators and mechanisms responsible for the inhibitory modulation of trout intestinal smooth muscle were examined using a series of putative mediators and substances known to modulate neurotransmission in mammalian systems. Frequency response relationships to transmural stimulation and concentration response relationships to 5-hydroxytryptamine, carbachol, and substance P were established on paired segments of rainbow trout intestinein vitro in the presence and absence of putative modulatory agents. Modulation of neurally-mediated contractions of trout intestine was achieved with dibutyryl cyclic AMP and forskolin, agents that increase intracellular levels of cyclic AMP. The effect appears to be at the level of the smooth muscle, since the adenylate cyclase activator, forskolin, inhibited muscarinic and serotoninergic contractions as well as transmurally stimulated contractions. Substance P-induced contractions were unaffected by forskolin. The endogenous agonists/neurotransmitters which would increase cyclic AMP levels in rainbow trout intestinal smooth muscle are as yet unknown. The effects do not appear to be modulated by vasoactive intestinal peptide (VIP), calcitonin, calcitonin gene-related peptide (CGRP), or agents that activate -adrenoceptors. Prostaglandin E₂ (PGE₂) and ₂-adrenergenic agonists are possible agents which will decrease contractility of the smooth muscle. They were only active in the proximal intestine and on transmurally stimulated contractions. The effects of both PGE₂ and ₂-agonists appear to be prejunctional, decreasing release of contractile neurotransmitters in the enteric nervous system.     

小麦胆色素原脱氨酶的电泳性质分析

经反应红１２０亲和层析纯化的小麦胆色素原脱氨酶（Ｐｏｒｐｈｏｂｉｌｉｎｏｇｅｎ ｄｅａｍｉｎａｓｅ,ＰＢＧＤ,ＥＣ．４,３,１,８）,在ＳＤＳ－ＰＡＧＥ和ＩＥＦ－ＰＡＧＥ上均显示一条带,表明已ＰＢＧＤ纯化至均一,它的亚基分子量３６ＫＤ,ｐＩ为４．８。酶活性染色呈一条带,表明无同工酶存在。ＰＡＧＥ显示两条带,证明小麦幼苗中存在酶与底物结合的中间物。脲梯度电泳呈现之字形,在４ｍｏｌ／Ｌ的脲浓度下可使酶     

Proliferative effect of PDGF and anti-proliferative activity of AMPK on vascular smooth muscle cells

AIM: To investigate the proliferative effect of platelet-derived growth factor (PDGF) and anti-proliferative activity of AMP-activated protein kinase (AMPK) on vascular smooth muscle cells (VSMCs). METHODS: The proliferation of VSMCs cultured with PDGF and activation of AMPK were observed. VSMCs were divided in 4 groups: control group; PDGF group; 5-aminoimidazole-4 -carboxamide-1-β-D-riboside (AICAR) group and AICAR+PDGF group. The time course of AMPK activation was determined. The protein level of mTOR was also measured. RESULTS: Compared with control group, the proliferative rate in PDGF group was significantly increased. The growth of VSMCs was inhibited in a time-dependent manner and the activity of p-mTOR was significantly decreased in AICAR group. Compared with control group, the expression of p-AMPK in PDGF group was significantly decreased, and that in AICAR group and AICAR+PDGF group was significantly increased. The expression of p-AMPK in AICAR+PDGF group was higher than that in PDGF group. The activity of p-mTOR in PDGF group was significantly higher than that in control group, while that of AICAR group and AICAR+PDGF group was significantly decreased. The expression of p-mTOR in AICAR+PDGF group was lower than that in PDGF group. CONCLUSION: Stimulation of VSMCs with PDGF promotes the cell proliferation, which can be inhibited by AICAR. The proliferation of VSMCs activated by AMPK is probably correlated with the down-regulation of mTOR expression.     

Angiotensin-(1-7) increases expression of ABCA1 and decreases content of cholesterol in THP-1-derived foam cells via AC-cAMP pathway

AIM: To establish the THP-1-derived foam cell formation and to evaluate the effects of angiotensin-(1-7) and MDL (an inhibitor of adenylate cyclase) on the expression of ATP-binding cassete transporter A1(ABCA1) and the content of cholesterol. METHODS: THP-1-derived macrophages were treated with oxidized low-density lipoprotein(ox-LDL) to develop into foam cells. The foam cells were divided into 4 groups: control group, MDL group, Ang-(1-7) group and MDL+Ang-(1-7) group. At 24 h after treatment, the content of cAMP was measured by ELISA. The mRNA and protein levels of ABCA1 were determined by real-time RT-PCR and Western blotting, respectively. The content of cholesterol was detected by high performance liquid chromatography. RESULTS: The cAMP, the mRNA and protein levels of ABCA1 in Ang-(1-7) group were significantly higher, and the content of cholesterol was significantly lower than those in control group (P<0.05). On the contrary, the cAMP, the mRNA and protein levels of ABCA1 in MDL group were significantly lower and the content of cholesterol was significantly higher than those in control group (P<0.05). The results in MDL+Ang-(1-7) group were between Ang-(1-7) group and control group. CONCLUSION: Ang-(1-7) inhibits the formation of foam cells by promoting the expression of ABCA1 and decreasing the content of cholesterol. MDL partly antagonizes the effect of Ang-(1-7) by inhibiting the adenylate cyclase and decreasing the content of cAMP.     

ACC deaminase-producing bacteria mediated drought and salt tolerance in Capsicum annuum

Influence of drought and salt stress on different morphological and physiological growth parameters in Capsicum annuum inoculated with our isolates was estimated during the present study. Bulkhorderia cepacia was reported to possess the maximal, whereas Citrobacter feurendii the least plant growth promoting efficacy under salt and drought stress. ACC Deaminase activity of purified B. cepacia, C. feurendii and Serratia marcescens was 12.8 ± 0.44, 12.3 ± 0.56 and 11.7 ± 0.53 μM αKB mg^?1 min^?1 respectively. Under drought stress, B. cepacia showed maximum tolerance as it produced 4.893 ± 0.06 mg/mg protein of exopolysaccharide followed by C. feurendii and S. marcescens that produced 4.23 ± 0.03 and 3.46 ± 0.05 mg/mg protein, respectively. Chlorophyll “a” concentration was recorded 5.7 gm L^?1 in B. cepacia inoculated plant (without stress) and was sustained till 2.9 gm L^?1 even under the highest tested drought period. Chlorophyll “a” concentration in the B. cepacia inoculated plant under the highest tested NaCl concentration was 3.2 gm L^?1. Thus, bacterial inoculation mitigates the effects of salinity by the proliferation of root system, increasing plant biomass proving to be potential bioinoculum for alleviating abiotic stress.     

Functional analysis of the G-protein α subunits FGA1 and FGA3 in the banana pathogen Fusarium oxysporum f. sp. cubense

The asexual fungus Fusarium oxysporum f. sp. cubense (Foc) is the causal agent of fusarium wilt in bananas (Musa spp.). This fungus poses a threat to banana production throughout the world. Here, two Foc genes, fga1 and fga3, were functionally characterized. These genes encode proteins homologous to the G-protein α subunits GPA1 from Saccharomyces cerevisiae and MAGC from Magnaporthe grisea, respectively. The deletion of fga1 leads to a phenotypic defect in colony morphology and reductions in vegetative growth, conidiation and pathogenicity against the banana plant (Musa spp. cv. Brazil), which was not observed for the Δfga3 deletion mutant. Intriguingly, both Δfga1 and Δfga3 deletion mutants showed declines in intracellular cyclic AMP levels and increases in heat resistance, suggesting that FGA1 regulates growth, development, pathogenicity, and heat resistance, whereas FGA3 modulates heat resistance, potentially through the cAMP-dependent protein kinase A pathway. These findings offer insights into the roles of the G-protein α subunits in the development and pathogenicity of the fungus Foc.