Enhanced Erythrocytic Lipid Peroxides and Reduced Plasma Ascorbic Acid,and Alteration in Blood Trace Elements Level in Dairy Cows with Mastitis

Oxidative stress has been associated in several inflammatory conditions and incriminated in the pathogenesis of many diseases. However, little information is available on the status of plasma antioxidant levels, essential components of important antioxidant enzymes such as copper, zinc and selenium in blood, and the end product of oxidative damage to the erythrocytic polyunsaturated fatty acids in inflammatory udder conditions. Blood samples were collected from three groups of dairy cows, with 21 in each group: animals with healthy udder, clinical mastitis, and subclinical mastitis. These animals were randomly selected from a herd on the basis of the California mastitis test, somatic cell count and total bacterial count. The mean plasma ascorbic acid concentration was significantly lower in cows with subclinical (p = 0.004) and clinical mastitis (p = 0.000) and the erythrocytic lipid peroxide levels were significantly (p = 0.000) higher in clinical mastitis as compared to controls. There was a significant decrease in mean blood zinc concentration in subclinical (p = 0.005) and clinical mastitis (p = 0.000), but an increase in mean blood copper level in the clinical mastitis group. It was concluded that the blood antioxidant status declines in inflammatory udder conditions, suggesting that incorporation of antioxidants may help in better management of mastitis in dairy cows.     

Antioxidant profile of cataractous English Cocker Spaniels

Cataracts have been attributed to oxidative injury in proteins and lipids. Primary defenses that directly protect the lens against oxidative damage include small molecule antioxidants (vitamin C, vitamin E, glutathione and carotenoids) and antioxidant enzymes (superoxide dismutase, catalase, and the glutathione enzyme systems – glutathione peroxidase, glutathione reductase and glucose-6-phosphate dehydrogenase). In humans, low plasmatic levels of vitamin C, vitamin E and carotenoids have been associated with a high risk of senile cataracts. Dogs are more prone to develop cataracts. A decrease in antioxidant defenses could be responsible for increased lens oxidation and cataract development. In this study we report the levels of erythrocytic enzymatic antioxidants (superoxide dismutase, catalase, glutathione peroxidase and glucose-6-phosphate dehydrogenase) and plasma vitamin C as well as malondialdehyde, in normal and cataractous English Cocker Spaniel dogs. Plasma vitamin C levels were consistently lower in cataractous dogs (20.17 μ m  ± 8.2 μ m ) when compared with normal dogs (24.1 μ m  ± 9.4 μ m ). These results indicate a possibly decreased synthesis in vitamin C, leading to lower aqueous humor levels of this vitamin. Considering that vitamin C levels in the aqueous humor may be responsible for lens antioxidant maintenance, and that these levels are obtained from plasma secretion through the ciliary epithelium, decreased plasma levels may indicate a decrease in the antioxidant capacity of the aqueous humor.     

植物体内自由基清除剂抗坏血酸研究进展

抗坏血酸(Ascorbic Acid,AsA)作为植物体内一种重要的自由基清除剂,在减少膜脂过氧化作用对细胞造成的损伤、增强植物抵抗逆境胁迫能力等过程中起着非常重要的作用。通过分析比较AsA的生物合成途径,总结AsA参与细胞分裂与伸长、作为辅酶参与细胞壁的形成、光保护作用、作为电子传递与信号转导的载体等生理功能,系统阐述AsA在植物逆境胁迫（主要包括温度胁迫、盐胁迫、生物胁迫等）中的保护机制及功能,强调AsA研究对于了解自由基清除剂在植物抗逆性作用以及清除自由基机理方面具有重要作用。本研究提出在牧草种子劣变方面AsA研究的不足,并分析展望了AsA研究发展的趋势。     

Aqueous humor and plasma concentrations of a compounded 0.2% solution of terbinafine following topical ocular administration to normal equine eyes

Objective To determine the transcorneal penetration and systemic absorption of a compounded 0.2% terbinafine solution following repeated topical administration to normal equine eyes. Sample population Six healthy adult horses with normal ocular examinations. Procedures One eye of each horse received 0.2 mL of a compounded 0.2% terbinafine solution every 4 h for seven doses. During the 1 h following administration of the final dose, multiple peripheral blood samples were obtained, and a single aqueous humor (AH) sample was collected at the end of the hour. AH and plasma concentrations of terbinafine were determined using high pressure liquid chromatography (HPLC). Stability of the formulation was assessed with HPLC analysis over a 14‐day time period. Results Terbinafine was not detected in the AH or plasma of any horse at any time point. No signs of ocular irritation or systemic toxicity were noted in any horse at any time point. The solution was stable over 14 days. Conclusion Topical ocular administration of compounded 0.2% terbinafine solution does not result in detectable AH or plasma levels following administration to normal equine eyes, suggesting its use for deep corneal or intraocular fungal infections in equine ophthalmology may be limited.     

Aqueous humor myocilin protein levels in normal, genetic carriers, and glaucoma Beagles

Objective The gene (myocilin: MYOC) has been attributed to be involved in over 6% of inherited types of human glaucoma, the highest correlation for any gene to date. This study determines myocilin protein levels in the aqueous humor (AH) of normal laboratory quality, genetic carrier (offspring of normal laboratory quality and POAG Beagles), and primary open angle glaucoma (POAG) Beagles. Materials and methods Eighteen dogs were used and classified as either normal, carrier or having mild, moderate or advanced POAG. A 0.1‐mL sample of AH was drawn from the anterior chamber of each dog in the study and frozen on dry ice. A modified Coomassie stain and Western blot, using a polyclonal rabbit antihuman myocilin antibody (Santa Cruz Biotechnologies, Santa Cruz, CA), was run on each sample to compare the myocilin levels. A purified human trabecular meshwork excreted myocilin protein sample was used as a control (Alcon Research Laboratories, Fort Worth, TX) and its band/densitometry measurement was defined as one unit of myocilin for comparisons. Results Comparisons of AH myocilin levels differed among normal laboratory quality, genetic carrier, and POAG Beagles at different stages of the disease. In the normal laboratory, Beagles the AH myocilin measured 0.817 ± 0.075 units (mean ± SEM); in the carrier Beagles the AH myocilin was 3.117 ± 0.290 units. As POAG progressed, myocilin protein levels also increased to 6.097 ± 0.810, 8.844 ± 1.079, and 17.228 ± 1.198 units in the early, moderate, and advanced forms, respectively. Overall comparisons between normal, carrier and all POAG Beagles combined showed significant differences (P < 0.0010). Individual comparisons between normal and carrier eyes showed significant differences (P < 0.0193). Comparisons between normal and all POAG eyes also showed significant differences (P < 0.0426). Conclusion This study shows myocilin protein is present in normal Beagles, markedly increased in POAG Beagles, and mildly increased in genetic carrier Beagles. There is a strong correlation between amounts of AH myocilin protein and the presence and severity of POAG. The exact role of AH myocilin levels in the genesis of ocular hypertension remains unresolved, but myocilin may adversely affect AH outflow.     

干旱胁迫下结缕草叶片抗坏血酸与相关生理指标变化的品种差异研究

通过盆栽试验,以日本结缕草与细叶结缕草为材料,研究了干旱胁迫下结缕草叶片AsA含量与相关生理指标的品种差异。结果表明,干旱胁迫下日本结缕草和细叶结缕草叶片中AsA含量与相关生理指标的动态变化规律基本相似,但品种间差异显著。干旱胁迫下2个品种的AsA含量和AsA/DHA均呈现先上升后下降的变化趋势,但日本结缕草下降的时间更早。干旱胁迫下叶片相对含水量、POD活性在2个品种中均呈下降趋势,但日本结缕草的下降趋势更明显,尤其在干旱胁迫后期。胁迫后日本结缕草叶绿素a与叶绿素b含量下降明显,而细叶结缕草变化不大。胁迫后两者的相对电导率和MDA含量均呈上升趋势,但日本结缕草增加的幅度更为显著。干旱胁迫后日本结缕草和细叶结缕草叶片Rubisco的含量均在第3天开始下降,胁迫后期日本结缕草Rubisco含量恢复到对照水平,而细叶结缕草Rubisco含量在胁迫后期显著高于对照。本研究结果表明,干旱胁迫下结缕草可以通过增加和维持叶片中AsA含量与POD活性来减缓Rubisco及叶绿素的降解,降低干旱胁迫对植株造成的氧化胁迫伤害程度,进而改善其抗旱能力。本研究结果进一步证实结缕草抗旱能力有品种差异,其中日本结缕草抗旱能力弱于细叶结缕草。     

抗坏血酸和水杨酸丸衣对NaCl胁迫下紫花苜蓿种子发芽特性的影响

为探究抗坏血酸（AsA）和水杨酸（SA）丸衣对NaCl胁迫下紫花苜蓿种子萌发的缓解效应,以紫花苜蓿种子为试验材料,采用不同浓度的AsA（1、2、4、8 mmol·L^-1）和SA（1、5、10、20 mmol·L^-1）对紫花苜蓿种子拌种后进行丸衣处理（未丸衣种子为CK₁,不做拌种处理的丸衣种子记为CK₂）,分析丸衣种子在NaCl胁迫下发芽特性的变化,以期获得能有效缓解紫花苜蓿种子盐胁迫效应的种子丸衣配方。结果表明,1.25%和1.50%的NaCl胁迫显著（P<0.05）降低了紫花苜蓿未丸衣种子的发芽率、发芽势、种苗长和种苗重,延长了平均发芽时间。AsA在1.25%NaCl胁迫下缓解效果不明显,4 mmol·L^-1AsA拌种后丸衣处理,能提高1.50%NaCl胁迫下紫花苜蓿种子的发芽率、种苗长。1 mmol·L^-1SA拌种后丸衣处理,能提高1.50%NaCl胁迫下紫花苜蓿种子的发芽势、发芽率和种苗长,而20 mmol·L^-1SA拌种后丸衣处理降低了紫花苜蓿种子的发芽率。说明AsA和SA丸衣对NaCl胁迫的缓解作用与其拌种浓度和NaCl胁迫浓度有关。本试验筛选出4 mmol·L^-1AsA和1 mmol·L^-1SA拌种丸衣配方对NaCl胁迫的缓解作用最优,该结果为AsA和SA丸衣应用于紫花苜蓿种子缓解NaCl胁迫提供依据。     

A comparison of plasma glucose and oxidative status in lactating dairy cows in summer and autumn

The objective of this study was to investigate the effects of the hot summer season on plasma glucose and oxidative stress markers. For two 14‐day experimental periods, namely periods 1 (July‐August) and 2 (October‐November), 12 and 14 lactating dairy cows, respectively, that were milked using an automatic milking system, were fed diets containing similar ingredients, and their milk production, plasma metabolites and oxidative status markers were investigated. Dry matter intake and milk yield were not affected by the experimental period. Rectal temperature at 18.00 hours and milk protein concentration in period 1 were higher and lower, respectively, than in period 2 (P < 0.05), suggesting that the hot summer season had an effect on the experimental dairy cows. Plasma glucose and the ascorbic acid + dehydroascorbic acid (AA) concentrations in period 1 were lower than in period 2 (P < 0.01). The plasma malondialdehyde (MDA) concentration did not differ between the experimental periods. The increase in the cellular AA uptake in peripheral tissues in period 1 might be a possible compensatory mechanism to balance the occurrence of reactive oxygen species and the antioxidant capacity in the cells, resulting in the absence of an effect of the hot summer season on plasma MDA concentration. © 2016 Japanese Society of Animal Science     

抗坏血酸引发对NaCl胁迫燕麦种子活力的影响

以燕麦种子为材料,通过对燕麦种子进行不同浓度(0、0.5、1.0、1.5和2.0 mmol·L^-1)的抗坏血酸(AsA)引发,然后在浓度为0、50、100和200 mmol·L^-1的NaCl胁迫下发芽,并分析其发芽率(G_p)、发芽指数(G_i)及平均发芽时间(MGT)的变化,以探讨外源AsA引发对盐胁迫种子活力的影响。结果表明:燕麦种子G_p、G_i和MGT在NaCl胁迫下显著(P<0.05)降低。随AsA浓度增加,燕麦种子G_p在浓度为100和200 mmol·L^-1的NaCl胁迫下呈先升后降的趋势,其G_i呈下降趋势,其MGT则呈增大趋势,而且不同AsA和NaCl浓度及两者的交互作用均对燕麦种子G_p、G_i和MGT影响极显著(P<0.01)。NaCl胁迫降低了燕麦种子的活力水平,而外源AsA引发可提高NaCl胁迫下燕麦种子的活力,该作用与AsA和NaCl的浓度具有密切关系。试验中1.0 mmol·L^-1的AsA引发对100和200 mmol·L^-1的NaCl胁迫效果最好。然而,外源AsA引发会延长燕麦种子在NaCl胁迫下的萌发时间。     

外源抗坏血酸对铜胁迫菊苣幼苗生长的缓解效应

为探究外源抗坏血酸(AsA)对铜(Cu)胁迫下菊苣幼苗生长的缓解效应,本研究以普那菊苣为试验材料,采用溶液培养法研究外源AsA对50μmol·L?1 Cu胁迫下菊苣幼苗的生长、Cu积累和生理特性的影响.结果表明,50μmol·L?1 Cu胁迫严重抑制了菊苣幼苗的叶绿素含量、光合作用和生物量的积累,加剧了细胞膜脂质过氧化...     

桦木酸对地塞米松致氧化应激小鼠血清指标的影响

本试验旨在研究桦木酸(BA)对地塞米松(Dex)诱导氧化应激小鼠血清指标的影响。将40只健康雄性昆明小鼠随机分为5组,即对照(NC)组、Dex组、0.25 mg/kg BA组、0.50 mg/kg BA组、1.00 mg/kg BA组,每组8只。NC组和Dex组灌服1%的可溶性淀粉,其余各组灌服混悬于1%可溶性淀粉溶液中不同剂量的BA,连续灌服14 d后,除NC组注射生理盐水外,其余4组均腹腔注射25 mg/kg Dex诱导氧化应激模型。15 h后,眼眶采血,收集血清。检测血清谷丙转氨酶(ALT)、谷草转氨酶(AST)和碱性磷酸酶(ALP)活性,总蛋白(TP)、白蛋白(ALB)、总胆固醇(TC)、甘油三酯(TG)、总胆红素(T-Bil)、钙离子(Ca~(2+))、细胞色素C(CytC)含量,总抗氧化能力(T-AOC)、抑制羟自由基能力、超氧化物歧化酶(SOD)活性、谷胱甘肽(GSH)和丙二醛(MDA)含量。结果显示:BA预处理后,能够显著或极显著降低Dex诱导氧化应激小鼠血清ALP活性及TG、T-Bil、CytC含量(P0.05或P0.01),且呈量效关系;低剂量BA(0.25、0.50 mg/kg)显著或极显著降低了血清MDA含量(P0.01或P0.05),但高剂量BA(1.00 mg/kg)反而极显著升高了其含量(P0.01);能够显著或极显著升高血清Ca2+和GSH含量、SOD的活性、T-AOC和抑制羟自由基能力(P0.05或P0.01),并呈量效关系;降低了血清ALT和AST活性,但影响不显著(P0.05),对血清TP和ALB含量无显著影响(P0.05)。由此可见,BA能够改善Dex引起的小鼠血清指标的变化,对Dex诱导的氧化损伤有预防性的保护作用。