LDH and LDH Isoenzymes of Synovial Fluid in the Horse

LDH is an intracellular enzyme, which when cells degenerate is released to the extracellular spaces and body fluids. Cells and organs in the mammalian body differ from each other with respect to their LDH isoenzyme patterns. These circumstances have led to the use of LDH isoenzyme determinations in laboratory diagnostic work. In the present investigation total LDH activity and LDH isoenzyme distribution in equine synovial fluid from healthy joints, joints with serous arthritis, osteochondrosis dissecans and arthrosis, were determined. The fluids from the diseased joints differed from normal synovial fluid with respect to total LDH activity, and the different joint diseases each seemed to give rise to a characteristic isoenzyme pattern. In order to examine possible sources of the increased LDH activity and altered isoenzyme patterns, blood plasma, red and white blood cells, synovial membrane and articular cartilage were also studied. It was found that LDH4 and LDH5 were present in high amounts in articular cartilage, and an increase in these isoenzymes was the most characteristic feature in synovial fluid from joints with arthrosis. The results were discussed in view of possible diagnostic value of isoenzyme determinations on synovial fluid.     

三种药物对猪棘头虫LDH同工酶的抑制试验

根据猪棘头虫与宿主（猪）血清的ＬＤＨ同工酶的差异，用０．１％硝硫氰醚、０．１％丙硫咪唑和０．１％吡喹酮分别对猪棘头虫雄虫、雌虫和猪血清的ＬＤＨ同工酶进行了抑制试验，结果除硝硫氰醚对蛭形巨吻棘头虫雄虫、雌虫的ＬＤＨ同工酶有抑制作用外，其余的试验组与对照组均无差异。硝硫氰醚对雄虫ＬＤＨ同工酶的第２、３、４带和雌虫ＬＤＨ同工酶的第２、３带有不同程度的抑制作用，特别是雌虫ＬＤＨ同工酶的第２带最敏感，在０．１％的浓度下，该酶带被完全抑制，即没显示出来，硝硫氰醚对雄虫和雌虫ＬＤＨ同工酶的极弱带（它们各自的第１带）均无抑制作用；临床实验也显示出硝硫氰醚对治疗猪棘头虫病有一定疗效，这些表明硝硫氰醚抑制蛭形巨吻棘头虫的ＬＤＨ同工酶活力可能是该药物对该虫体的作用机理之一。     

The Activity Ratio of the Cytosolic MDH/LDH and the Isoenzyme Pattern of LDH in the Peripheral Leukocytes of Dogs,Cats and Rabbits

The activities of malate dehydrogenase (MDH) and lactate dehydrogenase (LDH) and the pattern of the isoenzymes of LDH were determined in the peripheral blood leukocytes of dogs, rabbits and cats. Rabbits had significantly higher plasma glucose concentrations than dogs or cats. Feline leukocytes showed higher LDH and lower MDH activities than canine or rabbit leukocytes. The M/L ratio, defined as the MDH activity divided by the LDH activity in cytosolic fractions, was considered to be a good indicator with which to evaluate the metabolic state in animal tissues. The M/L ratio was highest in canine and lowest in feline leukocytes. LDH-2 and LDH-3 isoenzymes were dominant in canine leukocytes. LDH-1 and LDH-2 were dominant in rabbit leukocytes, whereas LDH-5 was dominant in feline leukocytes. It was evident that there were significant differences in energy metabolism between the leukocytes of dogs, rabbits and cats.     

Activities of enzymes in the malate-aspartate shuttle and the isoenzyme pattern of lactate dehydrogenase in plasma and peripheral leukocytes of lactating Holstein cows and riding horses

The activities of the enzymes involved in the malate-aspartate shuttle and lactate dehydrogenase (LDH) and the pattern of the isoenzymes of LDH were determined in plasma and peripheral leukocytes of lactating Holstein cows and thoroughbred riding horses as representative herbivorous animals. In the horse plasma, LDH activities were significantly lower and AST activities were significantly higher than those in the cow plasma. The specific activities of cytosolic malate dehydrogenase (MDH), LDH and AST in the horse leukocytes were higher than those in the cows. The cytosolic ratio of MDH/LDH activity (ML ratio) in the horse leukocytes was significantly lower than that in the cow leukocytes owing to significantly higher activities of LDH. The ML ratio was considered to reflect the difference in energy metabolism in leukocytes between cows and horses. The plasma LDH isoenzyme patterns of cow and horse showed the characteristic as herbivorous animals with dominance of LDH-1, -2 and -3. The LDH isoenzyme patterns with dominance of LDH-3 and -4 in the horse leukocytes were remarkably different from those in the cow leukocytes. There were significant differences in activities of malate-aspartate shuttle enzymes, ML ratio and LDH isoenzyme patterns in the cytosolic fractions of leukocytes between the lactating cows and the riding horses.     

绵羊组织器官LDH同工酶特异性研究

本研究利用不连续聚丙烯酰胺凝胶电泳法对绵羊的８种组织器官ＬＤＨ同工酶的分布及相对活性进行了分析测定。比较ＬＤＨ同工酶的酶谱特征。结果表明，绵羊的ＬＤＨ同工酶分布特征不同于其它动物，其相对活性有显著差异。骨骼肌中ＬＤＨ５活性比ＬＤＨ１强，Ｍ亚基比例大于Ｈ亚基；肝脏和心脏中ＬＤＨ１的活性最强。     

罗斯及印第安河鸡发育时期组织LDH同工酶变化

罗斯及印第安河鸡在胚胎第3d的混合胚中出现LDH_(1～3)3种同工酶(3条区带,梯度凝胶电泳),或LDH_(1～4)4种同工酶(6～7条区带,等电聚焦电泳);第7d检出心肌、胸肌和脑的5种同工酶(LDH_(1～5),5～7条区带);第12d检出肝脏的LDH_(1～5)5种同工酶(8或15条区带).组织LDH同工酶区带数随发育过程明显增多,同种鸡同一组织不同发育时期的LDH同工酶活性变化相差显著或极显著.在相同发育时期,印第安河鸡胸肌和肝脏的LDH_1相对活性均明显高于罗斯鸡(P<0.01).两种鸡心肌、胸肌、肝和脑组织LDH同工酶的等电点主要分布在pH6.0～8.2内.     

马关节滑液、血清乳酸脱氢酶及其同工酶和它们在疾病状态下的变化

用king氏法和聚丙烯酰胺凝胶电泳法测得马关节滑液和血清乳酸脱氢酶(LDH)及其同工酶正常值。滑液和血清5种LDH同工酶电泳迁移率相同。各种LDH同工酶的分子量和热稳定性均有明显差异。抗尿素作用,血清和滑液LDH同工酶基本相似。Mg~(++)是LDH激活剂,最佳激活浓度为10~(-3)M;Zn~(++)、Ca~(++)、Cu~(++)、Hg~(++)、谷胱甘肽、半胱氨酸、碘乙酸、EDTA等为LDH抑制剂。在四肢的急性或亚急性关节和骨疾病时,滑液LDH明显升高,其同工酶谱随疾病发生部位不同而不同,并与血清一致,但慢性关节疾病时LDH及其同工酶变化则不一致。     

Lactate dehydrogenase and its isoenzymes in the tissues and sera of clinically normal dogs

The total activity of lactate dehydrogenase (LDH) and the percentage distribution of its isoenzymes in the tissues and sera of clinically normal adult dogs are presented. Total LDH activity was greatest in skeletal muscle followed by heart muscle, kidney, small intestinal mucosa, liver, lung, pancreas and bone. Each tissue had a unique isoenzyme pattern and the proportions of the isoenzymes in serum suggested that liver is the source of normal serum LDH. The tissue isoenzyme patterns were similar to those obtained by other authors in human beings, horses, cattle, sheep and cats although in liver, differences between ruminants and monogastric animals including dogs were evident. The data presented provide a basis for the interpretation of serum LDH isoenzyme patterns in canine disease.     

Heat stability of serum lactate dehydrogenase and its isoenzymes in young and adult cattle and sheep. Evaluation of a relative heat stability test and serum determination of alpha-hydroxybutyrate dehydrogenase in diagnostic work

The heat stability of lactate dehydrogenase (LDH) has been investigated in serum from young and adult cattle and sheep. The thermoresistance of the isoenzymes was determined by electrophoresis of serum samples preincubated at different temperatures. Marked differences were found in the percentage distribution of isoenzymes in serum from the two species as well as in the heat stability. LDH in serum from sheep was inactivated at a lower temperature than that in serum from cattle, and inactivation occurred at a lower temperature in young than in adult animals. The enzyme was in both species less tolerant to elevated temperatures than what is reported for human serum. Procedures worked out for a so-called relative heat stability test of LDH in human clinical diagnosis may therefore give misleading results if they were applied uncritically to sera from these animals.The LDH isoenzyme pattern of some main organs in calves and sheep indicates that a serum heat stability test may be useful in the diagnosis of skeletal muscle injuries in sheep. In cattle the tissue isoenzyme distribution is assumed to be too uniform to give information about specific organ lesions either by serum electrophoresis or by a heating technique.In contrast to what has been reported in man, serum levels of α-hydroxybutyrate dehydrogenase (HBD) in cattle and sheep, as earlier reported in swine, are found to be far better correlated to total LDH than to the most thermostable isoenzyme, LDH₁.     

Activity of serum creatine kinase, lactate dehydrogenase and LD isoenzymes in piglets affected with congenital tremor: a case report.

The activities of serum creatine kinase (CK), lactate dehydrogenase (LD) and LD isoenzymes were studied in 14 Prestice black pied pigs from a herd affected with congenital tremor. Mean CK activity was 19.57 +/- 3.56 mu kat.l-1 for 6 adult pigs, and it was 21.03 +/- 1.33 mu kat.l-1 and 20.42 +/- 1.23 mu kat.l-1 for the affected (n = 5) and control (n = 3) piglets, respectively. No significant differences were demonstrable between the groups in CK activity. Total serum LD and LD-4 as well as LD-5 isoenzyme activities were higher in sows. Piglets affected with congenital tremor showed an increase in total LD enzyme and LD-5 isoenzyme activity. It is concluded that no relationship exists between congenital tremor and serum CK activity in piglets. At the same time, there is a positive relationship between congenital tremor and significantly (P < 0.01) elevated LD enzyme and LD-5 isoenzyme activity. The results allow us to suggest that total lactate dehydrogenase and LD-5 isoenzyme activities could be used as biological markers of congenital tremor in piglets.     

Lactate dehydrogenase isoenzymes in the lungs of sheep with acute and chronic pneumonia

Total lactate dehydrogenase and the absolute and percentage levels of its isoenzymes were measured in lung lesions and macroscopically normal areas of lung from lambs with chronic proliferative exudative pneumonia and acute pasteurella pneumonia. Lung lesions had a higher total enzyme activity which was associated mainly with increases in the activity of the LDH4 and LDH5 isoenzymes, particularly in chronic pneumonia, and gave lung lesions a considerable potential for altering the serum isoenzyme distribution. Thus, the nature of any changes in the serum isoenzyme distribution will depend on whether the isoenzymes are released from abnormal or normal areas of lung. This appears to be the first report on lactate dehydrogenase isoenzymes in ovine pneumonia.     

初生北京鸭4种组织LDH同工酶的分析

本文用薄层聚丙烯酰胺凝胶等电聚焦电泳对初生北京鸭的４种组织进行同工酶分析，结果表明初生北京鸭肝脏具有１１条区带，胸肌具有９条区带，肾脏具有１０条区带，心脏具有９条区带。从它们的Ａ亚基和Ｂ亚基的相对百分量的比值中可看出心脏和肾脏中的Ｂ亚基含量比肝脏中的多，相反，肝脏的Ａ亚基含量比心脏和肾脏含量多。胸肌的Ａ亚基和Ｂ基含量则是相近似的。     

Comparison of plasma biochemical parameters in Thoroughbred and Purebred Arabian horses during the same-intensity exercise

The objective of the present study was to compare changes of blood parameters induced by the same work and performed in the same conditions in two racehorse breeds, Thoroughbred and Purebred Arabian. The effect of moderate-intensity exercise was studied in 20 stallions--ten Thoroughbreds, aged 2-3 years and the same number of Purebred Arabians, 3-4 years old. All the horses were administrated the same effort test consisting in 1200 m gallop at a speed typical of the daily training sessions. Three jugular venous blood samples were collected for each horse: at rest, just after the end of the gallop and after 30-minute rest. In the gathered blood, a hemoglobin (Hb) concentration was determined as well as plasma level of glucose (Glc), triacylglycerols (TG), glycerol, free fatty acids (FFA), total plasma proteins (TP) and the activity of creatine kinase (CK), lactate dehydrogenase (LDH) and aspartate aminotransferase (AST). In the Arabian horses, an increase in levels of TP, glycerol, FFA and CK activity measured just after exercise was higher than that in Thoroughbreds. Similarly, after a 30-minute rest, a post-exercise rise of TP, AST, glycerol and FFA proved to be higher in the Arabian horses compared to that in the Thoroughbreds. Only TG plasma concentration measured 30 minutes following the effort was significantly lower in the Arabian horses than in Thoroughbreds. It can be concluded that the Thoroughbred horses adapted better to the effort test applied in this study as compared to the Purebred Arabian horses. The parameters related to lipid metabolism proved to be the most sensitive indicators of breed differences in relation to moderate-intensity exercise.     

Electrophoretic fractionation of creatine kinase isoenzymes and macroenzymes in clinically healthy dogs and cats and preliminary evaluation in central neurologic disease

Background: Information about the electrophoretic distribution of CK‐MM, CK‐MB, and CK‐BB, serum creatine kinase (CK) isoenzymes that are indicators of skeletal muscle, cardiac muscle, and brain lesions, respectively, and CK macroenzymes (macro‐CK1 and macro‐CK2) in dogs and cats with and without central neurologic disease is scant and equivocal. Objectives: The objectives of this study were to describe the electrophoretic distribution of CK isoenzymes and macroenzymes in healthy dogs and cats and to provide a preliminary assessment of the utility of CK enzymatic electrophoresis in dogs and cats with central neurologic disease. Methods: Electrophoretic separation of serum CK isoenzymes and macroenzymes was performed on freeze‐thawed serum samples from 20 healthy dogs and 3 dogs with central neurologic disease and from 14 healthy cats and 6 cats with neurologic feline infectious peritonitis (FIP). Electrophoretic separation was also performed on supernatants of homogenized brain, skeletal muscle, and cardiac muscle from both species, to assess the tissue distribution of isoenyzmes in dogs and cats. Results: CK‐MM was the predominant isoenzyme in the serum of healthy dogs and cats, followed by macro‐CK2 and CK‐BB in dogs and by both macroenzymes in cats. In dogs, CK‐MB was essentially absent from both serum and homogenized hearts. CK‐BB increased in dogs with neurologic disease. In cats, CK‐BB was essentially absent from serum, but was present in brain homogenates. Two of 6 cats with FIP had increased macro‐CK1 and increased CK‐BB activity. Conclusions: This study identified the electophoretic distribution of CK isoenzymes and macroenzymes of dogs and cats and provided encouraging data about the possible use of CK‐BB as a biomarker for canine neurologic disorders, but not for FIP.     

Growth performance, meat quality and activities of glycolytic enzymes in the blood and muscle tissue of calves infected with Sarcocystis cruzi

Growth performance and the pattern of glycolytic enzymes in the blood plasma were assessed during experimental Sarcocystis cruzi infection (1 x 10(5) sporocysts per calf) in six calves; five calves served as noninfected controls. At slaughter (68 or 88 days post infection), carcass weight, dressing percentages and several parameters of meat quality (pH, color brightness, rigor, water absorbing capacity, water binding capacity) were recorded. Moreover, enzyme activities were measured in muscle homogenates. Weight gain was significantly impaired by the infection. Activities of lactate dehydrogenase (LDH) and aldolase (ALD) significantly increased in the blood plasma of the infected calves during the chronic stage of the disease, while glucose-6-phosphate dehydrogenase (G6PDH) and isocitrate dehydrogenase (ICDH) were not significantly altered. This was accompanied by a significant decrease of enzyme activities in the Musculus longissimus dorsi (LDH, ALD), in the diaphragmatic musculature (ALD, G6PDH) and in the heart (LDH, ALD). Activities of LDH, ALD, ICDH and G6PDH were visualized by enzyme histochemistry within the developing sarcosporidial cysts. However, isoenzymes of parasite origin could not be demonstrated by agar-gel electrophoresis of muscle homogenates or blood plasma. It is concluded that sarcocystiosis of even moderate severity alters the performance of calves but not meat quality. Leakage of glycolytic enzymes from the affected muscles is the probable cause of increased plasma enzyme activities. Although these enzymes are also synthesized by the parasite, the contribution of parasite-derived enzymes to the observed changes of enzyme patterns remains in question.     

进化水平不同的动物和人血清乳酸脱氢酶同工酶电泳图谱的比较研究

应用聚丙烯酸胺垂直板梯度凝胶电泳分析了进化水平不同的17种动物和人血清乳酸脱氢酶(LDH)同工酶.17种动物是鲤鱼、中华大蟾蜍、蝮蛇、罗斯蛋鸡、山鸡、紫貂、银狐、貉、梅花鹿、马鹿、黑白花奶牛、新疆细毛绵羊、猪、马、大耳白兔、昆明小鼠和猴.在同一凝胶板、同一条件下,对这些动物和人血清LDH同工酶谱分析表明,LDH同工酶谱在各类动物之间存在明显差异.进化比较低级的动物(杂交鲤鱼除外),血清LDH同工酶谱带迁移率较小,接近阴极;反之,进化比较高级的动物,同工酶谱带迁移率较大,接近阳极.亲缘关系相近的动物,LDH同工酶谱相似.表明LDH同工酶谱带的差异与动物间的亲缘关系有关.同种不同个体的动物LDH同工酶谱差异不明显,只有杂交鲤鱼个体LDH同工酶谱存在明显差异.     

The effect of physiological parameters on serum lactate dehydrogenase isoenzymes in lambs

The effect of age, sex and growth rate on total serum lactate dehydrogenase (LDH) and its isoenzymes was assessed in Suffolk X Halfbred lambs from 1.5 days to 10 weeks old. The total LDH activity was higher at 1.5 days than in older lambs and the percentage of LDH₁ tended to increase while LDH₄ and LDH₅ decreased with age from 2 weeks, indicating that the isoenzyme distribution was changing towards the adult pattern. In female lambs, the percentage of LDH₁ was higher than in male lambs at 1.5 days, but little importance was attached to this finding since the difference was not significant at 10 weeks. No clear relationships existed between the level of total LDH or its isoenzymes and daily liveweight gain.The age-related changes were considered to be of greater significance than those related to sex and growth rate when interpreting serum LDH levels in lambs.     

Lactate dehydrogenase isoenzyme patterns in bovine liver tissue

Liver lactate dehydrogenase (LDH) isoenzymes in normal and diseased cows were analyzed electrophoretically. This method (histoelectrophoresis) was improved for the direct analysis of tissue LDH isoenzymes. The mean values of LDH 1 through LDH 5 in the livers of normal cows were 31.7, 24.8, 27.3, 12.8, and 3.3%, respectively. In cases with hydropic degeneration of the liver, the patterns revealed increases of LDH 1 and LDH 2 as compared to normal cows. The patterns showed a decrease of LDH 1 and an increase of LDH 2 in fatty change of the liver. Congestion of the liver alone decreased LDH 1 and increased LDH 3, LDH 4 and LDH 5. Necrosis of the liver decreased LDH 1 and LDH 2, and increased LDH 3, LDH 4 and LDH 5. It was suggested that the functional hepatocellular damage due to anoxia might be a important factor of the change of liver LDH isoenzyme patterns. We have attempted to standardize the LDH isoenzyme patterns by using a computer under various conditions. In cases with hydropic lesions, the diagnostic sensitivity (DS) was 53% (28 of 53 cases) and the predictive value of positive tests (PVPT) was 100% (28 cases of 28 cases selected). In cases with congestive or necrotic lesions, DS was 41% (9 of 22 cases) and PVPT was 69% (9 cases of 13 cases selected).     

如皋鸡血浆酶活力及其与体重的相关性研究

为了研究如皋鸡血浆酶活力及其与体重的相关性,试验测定了如皋鸡2、4、6、8、10、12周龄体重及血浆LDH、HBDH、MAO、MDH、CK、5′-NT、ALT、ADA、ALP、ICDH的活力。结果表明:①2周龄体重与LDH、HBDH、MDH、CK相关极显著(P<0.01),8周龄体重与LDH、HBDH呈显著负相关(P<0.05),12周龄体重与ICDH相关极显著(P<0.01)。②周龄间,体重与5′-NT、ALP呈显著负相关(P<0.05)。③除5′-NT为中等遗传力外,LDH、HBDH、MAO、MDH、CK、ALT、ADA、ALP、ICDH均为高遗传力。④周龄内,血浆LDH与HBDH、MAO、MDH、CK,HBDH与MAO、MDH,MAO与MDH,CK与HBDH、MDH,ALP与5′-NT的偏相关程度较高。⑤周龄间,LDH与HBDH、MAO、MDH、CK、5′-NT、ALP,HBDH与MAO、MDH、5′-NT、ALP,MAO与MDH,CK与HBDH、MDH、ALP,ALT与ICDH,ALP与5′-NT间相关系数达到显著(P<0.05)或极显著水平(P<0.01)。因此,血浆酶活力的相关研究可以为体重等性状的选择提供理论依据。     

Lactate dehydrogenase and creatine kinase isoenzyme levels in the tissues and serum of normal lambs

The normal activities of lactate dehydrogenase and creatine kinase isoenzymes in the tissues and serum of clinically normal five-and-a-half-month-old lambs are presented. The percentage distribution of the lactate dehydrogenase isoenzymes in serum, liver, heart, lung and skeletal muscle were in agreement with previous studies but the distribution in ovine abomasum, small intestine, large intestine and red blood cells has not been previously described. Up to five creatine kinase isoenzymes were detected in ovine tissues and four in serum. One creatine kinase isoenzyme present in serum and tissues was thought to represent a mitochondrial isoenzyme which is absent from the normal serum of other species. Estimations of both lactate dehydrogenase and creatine kinase isoenzymes allowed all the tissues examined to be distinguished and were therefore more likely to allow tissue-specific isoenzyme patterns to be detected in serum than the estimation of the isoenzymes of either enzyme alone.