Effects of lead nitrate on the activity of metabolic enzymes during early developmental stages of the African catfish, <Emphasis Type="Italic">Clarias gariepinus</Emphasis> (Burchell, 1822)

Glucose-6-phosphate dehydrogenase (G6PDH), lactate dehydrogenase (LDH) and pyruvate kinase (PK) are key metabolic enzymes. G6PDH has been used as a biomarker of pollution-induced carcinogenesis in fish. LDH has been used as marker of lesions in toxicology and clinical chemistry, and PK catalyses the conversion of phosphoenol pyruvate to pyruvate, with regeneration of ATP. The effect of different concentrations of lead nitrate on the activity of these enzymes in two different early ontogenetic stages (embryonic and free embryonic stage) of the African catfish Clarias gariepinus was investigated. Embryo homogenates were used for measurements of G6PDH, LDH and PK activity spectrophotometrically at 340 nm and 25°C. The ontogenetic variations of the three enzymes during early ontogeny, from the 30 h to the 168 h post-fertilisation stage (PFS) (beginning of exogenous feeding), were studied. There was a significant decrease in activities of all three enzymes from 30 h-PFS to 96 h-PFS, followed by a significant increase in G6PDH and LDH. PK showed insignificant fluctuations in activity. Different patterns of enzyme activities were recorded due to exposure to different lead nitrate concentrations (100 μg/l, 300 μg/l and 500 μg/l). In the pre-hatching stage (30 h-PFS) the activity of the three enzymes increased at exposure to 100 μg/l lead nitrate and then decreased with increasing dose. In the post-hatching stages (48 h-PFS–168 h-PFS) G6PDH activity increased and LDH activity decreased with increasing lead concentrations. Unlike G6PDH and LDH, the PK enzyme fluctuated during the post-hatching stages and did not reveal a specific trend of response (increase or decrease) with increasing lead concentrations. Therefore, the measurement of G6PDH and LDH activities, but not PK activity, could be useful biomarkers of intoxication to reveal the embryotoxic potential of lead nitrate in fish embryos. The post-hatching stages of the African catfish are more sensitive than the pre-hatching stage (30 h-PFS) is, probably due to the protective capacity provided by the hardened chorion. The interaction and the main effects of age and lead doses were found to be highly significant, referring to the great impact of lead on these enzyme systems with increasing early development.     

患“裂头病”黄颡鱼内脏组织中LDH的变化

使用聚丙烯酰胺凝胶电泳法,分析了健康黄颡鱼(Pelteobagrus fulvidraco)与患病个体的肝脏、脾脏、心脏、肾脏、脑组织中的乳酸脱氢酶同工酶的变化。结果显示,患病个体组织中的LDH谱带与健康个体有明显差异,主要表现为谱带染色变浅、谱带缺失;但在心脏中,除了缺失谱带外,还增加了1条LDH0带。     

Determination of normal values of some blood serum enzymes in <Emphasis Type="Italic">Acipenser stellatus</Emphasis> Pallas

Hematological studies on fishes have assumed greater significance due to the increasing emphasis on pisciculture and greater awareness of the pollution of natural water resources. Such studies have generally been used as an effective and sensitive index to monitor physiological and pathological changes in fishes, especially in the management of endangered species. This study was undertaken to establish a reference range for six important blood serum enzymes. Serum samples of 40 Acipenser stellatus (20 female and 20 male) were analyzed, and serum enzyme values were determined. The reference ranges for the total samples and also for each sex were determined. The activities of measured enzymes in serum were: aspartate aminotransferase (AST) 265.60 ± 56.55 IU/l, alanine aminotransferase (ALT) 5.65 ± 1.18 IU/l, acid phosphatase (ACP) 15.63 ± 2.59 IU/l, lactate dehydrogenase (LDH) 2007.15 ± 521.97 IU/l, creatine kinase (CK) 6,596.05 ± 1,807.19 IU/l, and alkaline phosphatase (ALP) 69.05 ± 13.04 IU/l. There were significant differences between male and female fish in terms of AST and CK activity (P < 0.05). These may be related to the season of sampling and changing physiological cycles during spawning during which period the sexual hormones and stress are more obvious. However, there were no differences in the activity of ALP, ACP, LDH, and ALT between sexes. The correlations between measured enzymes were also determined.     

Thermal modulation of pyruvate metabolism in the freshwater prawn Macrobrachium malcolmsonii: the role of lactate dehydrogenase

Temperature-induced alterations in the activity of the enzyme lactate dehydrogenase (LDH) were evaluated in the freshwater prawn Macrobrachium malcolmsonii in three groups of juveniles: controls maintained at 27±2 °C; test prawns exposed to 35 °C; test prawns exposed to 15 °C. Changes in LDH activity and lactate levels in key tissues were assessed after 48 hrs. LDH in the skeletal muscle of the prawns was also subjected to kinetic analysis at different temperatures. Native polyacrylamide gel electrophoresis (PAGE) analysis and colorimetric estimation revealed decreased LDH activity (compared to controls) in the gill, heart and haemolymph, but not in the skeletal muscle or hepatopancreas, of test prawns exposed to 15 °C; however, lactate levels were significantly lower in all the tissues of these test prawns. Conversely, prawns exposed to 35 °C revealed elevated LDH activity in all the tissues, barring the skeletal muscle, while lactate levels were significantly higher (compared to controls) in all the tissues of these prawns. Kinetic analysis of LDH in the skeletal muscle at different assay temperatures revealed temperature-dependent kinetic properties. The differences observed in LDH activity and levels of lactate in various tissues of prawns exposed to low and high temperatures suggest aerobic and anaerobic patterns of pyruvate metabolism at respective temperatures. The results obtained by kinetic analysis of LDH in the skeletal muscle suggest the occurrence of an adaptative response involving this enzyme that enables M. malcolmsonii to cope with effects of thermal stress. This revised version was published online in July 2006 with corrections to the Cover Date.     

低氧环境下卵形鲳鲹的氧化应激响应与生理代谢相关指标的研究

文章测定了急性和慢性低氧胁迫后卵形鲳鲹(Trachinotus ovatus)的氧化应激和生理代谢相关指标。结果显示,在(23±0.7)℃下,体质量(31.59±3.01)g的鱼在急性低氧胁迫条件下的个体成活率为100%,在慢性低氧胁迫条件下的成活率则不断下降,第11天时降为实验初始时的50%。急性低氧胁迫过程中随低氧胁迫时间延长鳃过氧化氢酶(CAT)活性下降,第3小时最低,随后升高,第24小时显著高于其他各组(P0.05)。还原型谷胱甘肽(GSH)、丙二醛(MDA)含量、超氧化物歧化酶(SOD)活性随低氧持续先上升后恢复至正常水平,慢性低氧胁迫下鳃CAT活性与对照组相比显著降低(P0.05)。MDA、GSH含量和SOD活性则均显著升高(P0.05)。肝糖原(LG)在急性低氧胁迫过程中随低氧呈先下降后恢复的趋势,第12小时降至最低,第24小时恢复至对照组水平,慢性胁迫后LG下降。乳酸脱氢酶(LDH)水平在急性低氧胁迫过程中随低氧先升后降,第3小时达最大值,第24小时下降为对照组水平,慢低氧胁迫后LDH水平显著高于对照组(P0.05)。     

大口黑鲈原代肝细胞的培养及其应用于CYP450活性的诱导

体外培养大口黑鲈(Micropterus salmoides)原代肝细胞,观察其在培养过程中的形态变化,同时检测培养上清液中的乳酸脱氢酶(LDH)、白蛋白(ALb)含量,从而判定肝细胞的增殖和代谢能力,进而应用于CYP450的诱导研究。结果表明:培养5 d后,肝细胞连接成片,分裂增多;培养至7 d,细胞渐至单层;14 d后,细胞停止生长,出现老化迹象。培养至第3~4天的细胞上清液中LDH的渗出量呈上升趋势,在第4天时达到峰值,随着培养时间的延长,肝细胞的酶渗出量逐渐减少。ALb的分泌量在第3~5天呈上升的趋势,第4~8天维持在较高水平,在第5天达到最高,此后随着培养时间的延长,ALb的分泌量呈下降趋势,故选择培养至第5天的大口黑鲈肝细胞应用于CYP450酶系中的氨基比林-N-脱甲基酶(ANDM)的诱导研究。40μM利福平诱导24 h后,ANDM活性最高。ANDM的诱导研究为鱼类细胞药物代谢酶体外诱导奠定基础。     

甘子河裸鲤肌肉营养成分和乳酸脱氢酶同工酶的分析

用常规法测定和分析了体质量280g的甘子河裸鲤肌肉的营养成分。鱼体粗蛋白含量为61.77%(干质量百分率),必需氨基酸含量为31.88mg,占氨基酸总量的49.67%;采用聚丙烯酰胺凝胶电泳法分析了甘子河裸鲤的肝胰脏、肾脏、心、脑和肌肉中的乳酸脱氢酶同工酶。结果显示,不同组织间乳酸脱氢酶存在特异性,在脑中的活性最强。     

The effect of migration distance and timing on metabolic enzyme activity in an anadromous clupeid, the American shad (Alosa sapidissima)

The American shad (Alosa sapidissima) is a common anadromous fish species with ecological and economic importance on the east coast of North America. This iteroparous species undergoes an energetically costly upriver spawning migration in spring. To evaluate metabolic changes associated with this migration, we assessed the maximum activity of five metabolic enzymes (citrate synthase (CS), phosphofructokinase (PFK), lactate dehydrogenase (LDH), -hydroxyacyl coenzyme A dehydrogenase (HOAD), alanine aminotransferase (GPT)) in liver, red muscle and white muscle during upstream migration in two successive years in the Connecticut River. For aerobic capacity (CS), glycolytic capacity (LDH) and utilization of stored lipid and protein energy (HOAD and GPT), there is a general pattern of increasing activity with a subsequent decline at the most upriver sites. Red muscle CS activity increased by as much as 40% during the migration while white muscle CS activity was 120% higher in the river than in the ocean. In contrast, muscle anaerobic capacity, indicated by PFK, was low as fish entered the river and then increased 5-fold at the most upriver sites. White muscle HOAD increased 30% while red muscle HOAD and muscle GPT increased as much as 60%. There were interannual and sex-associated differences in enzyme activity during upstream migration and through time at a single location. In some cases interannual differences can be larger than those seen during upriver migration as in the case of red muscle CS where sampling years differed by 125%. These interannual differences may be a result of differing river conditions that affect migratory effort. We have demonstrated that American shad use tissue and sex-specific regulation of enzyme activity during migration and we suggest that American shad metabolically acclimate to upstream migration.     

Lactate dehydrogenase isozymes in the trunk and cardiac muscles of an antarctic teleost fish,Notothenia neglecta Nybelin

The distribution and kinetics of lactate dehydrogenase (LDH) isozymes in the red and white trunk muscles, and cardiac muscle of an antarctic teleost fish (Notothenia neglecta Nybelin) have been studied. Pyruvate inhibition of LDH in all three muscle types is very low, being less than 50% even at a concentration of 60mM pyruvate. Activity versus pyruvate concentration profiles are not significantly different for LDH in all three muscle types. The Michaelis constant (Km) for pyruvate was not significantly different for all three LDH's. Raising the assay temperature caused an increase in Km of similar form in all three muscle types, while Km was lowest at the lowest assay temperature (–1°C). When samples were run on a polyacrylamide gel, the bands stained specifically for LDH activity appeared at identical positions as those of the H2M2 band of the standards.It would appear therefore that the LDH isozyme found in the red and white trunk muscle ofN. neglecta is identical to that in cardiac muscle. This fact is discussed in relation to the physiological ecology of antaretic fishes, and the metabolic constraints imposed by their habitat, including their apparent low capacity for utilising glycolytic fuels.     

Ctenocephalides canis and Ctenocephalides felis infestations of dogs and cats. Biology of the agent, epizootiology, pathogenesis, clinical signs, diagnosis and control

A review is presented of the biology, epizootiology, pathogenesis, clinical features, diagnosis and treatment of canine and feline Ctenocephalides canis and C. felis infestation. Also data are given on the prevalence of fleas in dogs and cats during a year at the 1st Animal Medical Hospital, Munich Veterinary Faculty. 5.5% of the dogs and 18.9% of the cats were infested with fleas.     

Development and validation of a new dot blot test for the detection of Paramoeba pemaquidensis (Page) in fish

In this study, the development of a dot blot assay to assess amoebic gill disease (AGD) using non-lethal gill mucus samples is described and its performance validated by comparing the assay with the indirect fluorescent antibody test (IFAT), the 'gold standard' test. The agreement between the two tests was high, with a positive predictive value of 95% and negative predictive value of 93%, with a corrected κ value of 0.88. The sensitivity and specificity of the test were 97 and 91%, respectively. The dot blot is both sensitive and specific for Paramoeba pemaquidensis and is formatted so that large numbers of samples can be conveniently analysed.     

Babesiosis of dogs in Germany: epidemiologic case analysis

Between January 1987 and February 1990 Babesia infections were detected in 320 dogs in Germany by means of microscopical and/or serological methods. It was found, that 316 dogs were infected with Babesia canis and 4 animals with Babesia gibsoni. Of the Babesia-canis-positive dogs 184 were abroad up to 4 months before diagnosis, mainly in France, Spain and Italy, but also in Hungary, Greece, Jugoslavia, Portugal, Morocco, Togo, Pakistan, Sri Lanka, Malaysia, Turkey, Romania, Austria and the Netherlands. For further 36 dogs the possible place of infection for Babesia canis could not be clarified geographically. 5 dogs each were simultaneously infested with Rhipicephalus sanguineus and Dermacentor reticulatus, respectively. The four dogs infected with Babesia gibsoni were previously in Sri Lanka (2), Brazil (1) or Algeria/Kenya (1). In 88 dogs from the Offenburg/Lahr/Freiburg area, which were not abroad, infections with Babesia canis were diagnosed from January to June as well as from September to December, however, most cases occurring in April and May. Of these dogs approximately 20% were found to be infested with Dermacentor reticulatus. These ticks were also collected on the vegetation in the Offenburg area. Therefore, an endemic focus of Babesia canis can be deduced in the area of Offenburg/Lahr/Freiburg and Dermacentor reticulatus as vector also in Germany.     

Influence of <Emphasis Type="Italic">Tribulus terrestris</Emphasis> on testicular enzyme in fresh water ornamental fish <Emphasis Type="Italic">Poecilia latipinna</Emphasis>

The influence of Tribulus terrestris on the activities of testicular enzyme in Poecilia latipinna was assessed in lieu of reproductive manipulation. Different concentrations of (100, 150, 200, 250, and 300 mg) Tribulus terrestris extract and of a control were tested for testicular activity of enzymes in Poecilia latipinna for 2 months. The testis and liver were homogenized separately in 0.1 mol/l potassium phosphate buffer (0.1 mol/l, pH 7.2). The crude homogenate was centrifuged, and supernatant obtained was used as an enzyme extract for determination of activities. The activities of testicular functional enzyme ALP, ACP, SDH, LDH, and G6PDH levels were changed to different extent in treated groups compared with that of the control. The total body weight and testis weight were increased with the Tribulus terrestris-treated fish (Poecilia latipinna). These results suggest that Tribulus terrestris induced the testicular enzyme activity that may aid in the male reproductive functions. It is discernible from the present study that Tribulus terrestris has the inducing effect on reproductive system of Poecilia latipinna.     

盐度对罗氏沼虾能量代谢和运动能力的影响

为研究盐度对罗氏沼虾(Macrobrachium rosenbergii)能量代谢和运动能力的影响, 设置了 0 (对照)、4、8 和 12 共 4 个盐度胁迫水平, 研究了罗氏沼虾在胁迫 48 h 后的耗氧率、鳃丝和肌肉能量代谢酶活性及其游泳和弹跳能力。结果显示, 耗氧率在盐度升至 4 时并无显著变化(P＞0.05), 但 8 和 12 盐度组的耗氧率显著高于对照组(P＜0.05)。 鳃丝己糖激酶(HK)、磷酸果糖激酶(PFK)和乳酸脱氢酶(LDH)活性在不同盐度条件下并无显著变化(P＞0.05), 但鳃丝丙酮酸脱氢酶(PDH)和细胞色素 C 氧化酶(COX)活性在盐度为 8 时显著升高(P＜0.05), 并且鳃丝 PDH 和 COX 活性均与耗氧率呈显著线性正相关(P＜0.05)。盐度在 8 时罗氏沼虾的游泳足肌肉和腹部肌肉 HK、PFK 和 LDH 活性并无显著变化(P＞0.05), 但游泳足肌肉和腹部肌肉 PDH 和 COX 活性显著下降(P＜0.05); 盐度升至 12 时游泳足肌肉和腹部肌肉 HK、PFK、LDH、PDH 和 COX 活性均显著下降(P＜0.05)。运动能力结果显示, 盐度升至 8 时游泳能力显著下降(P＜0.05), 盐度升至 12 时弹跳能力显著下降(P＜0.05)。游泳能力与游泳足肌肉 PDH 和 COX 活性呈显著线性正相关(P＜0.05); 弹跳能力与腹部肌肉 HK、PFK 和 LDH 活性呈显著线性正相关(P＜0.05)。研究表明, 罗氏沼虾通过增加氧气摄取用于鳃丝有氧代谢以应对盐度胁迫, 但这些生理调节导致肌肉能量代谢酶活性下降, 造成罗氏沼虾的游泳和弹跳能力减弱。     

超低温冷冻对斑尾刺虾虎鱼卵中酶活性的影响

研究了超低温冷冻保存(-196℃)对斑尾刺虾虎鱼成熟卵中总ATP酶、肌酸激酶(CK)、琥珀酸脱氢酶(SDH)、乳酸脱氢酶(LDH)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GSH-PX)和丙二醛(MDA)等酶活性的影响。结果表明,经过冷冻保存后,总ATP酶、CK、SDH和LDH的活性显著下降(P<0.05),同时可见添加抗冻剂组比未添加抗冻剂组下降幅度更大(P<0.05);SOD、CAT和GSH-PX的活性也显著下降(P<0.05),未添加抗冻剂组比添加抗冻剂组下降更明显(P<0.05);MDA的活性显著升高,且未添加抗冻剂组显著高于添加抗冻剂组(P<0.05)。超低温冷冻和是否添加抗冻剂都对斑尾刺虾虎鱼卵中酶活性有显著性影响。     

The congenital portosystemic shunt in dogs and cats. I

An overview of the circulation of the liver and of the pathogenesis of hepatic encephalopathy as a result of portal vascular anomalies is given. Clinical signs associated with portal systemic shunts are described on the basis of 16 cases, 14 dogs and 2 cats. These animals ranged in age at the time of presentation from 4 months to 7 years. The predominant abnormality observed were central nervous signs, which differed in severity. 15 animals showed a reduction in liver size. The different techniques of contrast angiography allowing demonstration of a portal systemic shunt are presented along with a discussion of the pros and cons of each. Additionally the significance of making portal venous pressure measurements prior to each angiography is also explained. In most cases mesenteric portography was chosen. Based on their location the anomalies could be categorized as intrahepatic (4 dogs) or extrahepatic (10 dogs, 2 cats). In both groups breeds of various size are represented. The extrahepatic shunts could be further described as portal-caval (n = 5), portal-phrenic (n = 4) and portal-azygos (n = 3). In five of the older animals angiography showed in addition some hepatic perfusion by the portal vein. Laboratory evaluation revealed increased resting blood ammonia concentrations (greater than 200-912 micrograms/100 ml) in all animals. Seven dogs had definitely subnormal BUN concentrations (less than 10 mg%) and ten dogs low total plasmaprotein levels (less than 5.4 g%). Free amino acids (24) were determined in four dogs and a lowered hepatic encephalopathy index (less than 1.64) was found. Medical palliative therapy to control the clinical signs is discussed. The only effective long term therapy is, however, surgery. The shunt vessel is narrowed so that a greater volume of portal blood reaches the liver. Experience gained from the surgical therapy of 14 animals is presented. Ten of these survived well without requiring further therapy at a later time. Finally the etiology, prognosis, and differential diagnosis are summarized.     

不同水温下虹鳟血清酶的活性

使用日立7170A全自动生化分析仪,测定水温14℃、19℃、23℃时虹鳟(Salmo irideus)血清酶活性。结果表明:在3个温度下,虹鳟血清碱性磷酸酶(ALP)和肌酸激酶(CK)活性随温度上升而降低,谷丙转氨酶(ALT)活性随温度上升而升高,谷草转氨酶(AST)活性表现为先升高后降低,乳酸脱氢酶(LDH)活性表现为先降低后升高。     

Changes in the behavior of dogs after castration

This study is based upon a written survey of keepers of neutered dogs about the behaviour of 209 male and 382 female dogs. The main findings are: Male dogs show behavioural changes after castration more often and more distinctly than female dogs after neutering. Behavioural problems in most cases are reduced or have even disappeared after neutering (male dogs 74%, female dogs 59%). At best, hypersexuality and connected problems are changed as expected. 49 of 80 aggressive male dogs and 25 of 47 female dogs are more gentle after neutering. 10 bitches appeared to be aggressive only after being neutered. Particularly feeding behaviour changes in 42% of the male dogs and 32% of the female dogs towards an increased intake of food, which also leads to an increase in body weight. This corresponds to decreasing activity, which is indicated by increasing time of rest (male dogs 36%, female dogs 18%) and decreasing motivation to move. Motivation for playing, watchfulness and perseverance change more seldomly and sometimes increase. The character of the neutered animals is predominantly described as "devoted, friendly and kind". Changes of behaviour following neutering depend on many influencing factors. Above all effective obedience training, but also the family situation of the owner, time factors, conditions of keeping and contact with other dogs have different impacts on the control of the individual behavioural problems.