Lactate dehydrogenase isoenzyme distribution and patterns in chicken organs.

Unlike most mammals, chicken lactate dehydrogenase isoenzymes cannot be separated using the 'Titan-Gel' electrophoresis. However, using isoelectric focusing at a pH range of 3.0 to 9.0, a good and clear separation of all five isoenzymes was achieved. Generally, three characteristic groups were seen: (a) those having a cathodic domination (breast muscle and serum) with mainly lactate dehydrogenase-5 (b) those having an anodic domination (heart, muscle, liver, pancreas, kidney, erythrocytes) of mainly lactate dehydrogenase - 1 and 2 and (c) those with a more uniform distribution (spleen, lung, and brain). The total lactate dehydrogenase activity was the highest in the breast muscle, followed by the heart muscle, liver and serum with the lowest activities in the lung and pancreas.

Lactate dehydrogenase isoenzyme patterns in bird, carp and mammalian sera.

Isoenzyme patterns of lactate dehydrogenase (EC 1.1.1.27) in avian sera are described and compared with those of carp and some mammals. The predominant portion of lactate dehydrogenase in avian sera was concentrated in the muscular form of the enzyme (lactate dehydrogenase 5). Most mammalian sera (with the exception of rat serum) showed a different pattern, in which the main portion of lactate dehydrogenase activity migrated in the first three anodic fractions. Fish serum lactate dehydrogenase isoenzymes were distributed similarly to those of mammals. The electrophoretic mobility of bird lactate dehydrogenase isoenzymes in a pH gradient of 3 to 9 was different from that of carp, cattle and rabbit. Bird lactate dehydrogenase isoenzymes were localized in the pH region of 5.8 to 8.1. In contrast, the mammalian isoenzymes were more acidic, with pI values in the range of 4.5 to 7.3. Lactate dehydrogenase isoenzymes of carp migrated in a narrow pH range of 5.2 to 6.5.

[New findings on serum lactate dehydrogenase isoenzymes in pigs during slaughter]. / Nové poznatky o izoenzýmoch laktátdehydrogenázy v krvných sérach osípaných pri porázke.

In the article we describe lactate dehydrogenase-(LD) (EC 1.1.1.27) isoenzyme pattern detected in the sera of pigs at slaughter. The pattern was different from that of normal serum (Fig. 1) and was characterized by the occurrence of an extra LD-fraction in the cathodic site of LD4 (Fig. 2). This fraction was unusual due to its unwillingness to separate by native polyacrylamide gel electrophoresis (PAGE) and took shape of a diffuse zone. The presence of the extra LD-zone caused a proportional decrease in quantitative distribution of the other LD forms, especially LD1 to LD3, in slaughtered pig sera (Tab. I). We examined the homogeneity of an apparent LD5-fraction using gel isoelectric focusing (IEF). We found out that after separation in a gradient of pH (3-9) two to three new extra bands with LD activity appeared in the area with relatively high pH value (pH 9) (Fig. 3). Their localization in the gradient of pH was greatly different from that of true LD molecules, the latter being situated in more acidic area. It is obvious from the finding described above that the diffuse LD-zone, detected in the serum of pigs at slaughter by native PAGE, was in no case a homogeneous protein. Consequently, it eliminates a possibility that the extra LD fraction reflects an increased LD5 activity in serum of affected animals. On the contrary, the IEF showed that the diffuse LD-zone consisted of two to three electrophoretically distinct proteins with relatively high pI values. As these proteins differed in their electrophoretic properties from the true LD isoenzymes we denoted them LD-like proteins. An origin of the unusual LD-like proteins detected in the serum of pigs at slaughter remains unknown for us for the time being.

[Lactate dehydrogenase isoenzymes in mammalian and chicken serum]. / Izoenzýmy laktátdehydrogenázy v cicavcích a kuracích sérach.

In the article we describe characteristics of lactate dehydrogenase (LD) (EC 1.1.1.27) isoenzymes of fowl origin. We compare them with characteristics of evolutionary different mammalian forms of the enzyme. Separations of LD isoenzymes have been done using the most progressive electrophoretic techniques available at present. They included electrophoresis in homogeneous and gradient polyacrylamide gels (PAGE) as well as isoelectric focusing (IEF). A typical densitometric pattern of serum LD isoenzymes obtained by gradient PAGE is illustrated in Fig. 1. It is obvious that LD isoenzymes of all investigated animals have been well separated under applied experimental conditions, with an exception of fowl serum. We succeeded in separating fowl LD isoenzymes using isoelectric focusing. It was possible to distinguish five fractions of lactate dehydrogenase (Fig. 2) by this technique. As shown in Fig. 2, mobility of avian isoenzymes in the gradient of pH differs from that of their mammalian analogues. Fowl LD isoenzymes were localized in cathodic part of IEF-gram. In the case of mammalian isoenzymes (cattle and rabbit), we found LD4 and LD5 forms of the enzyme in this part. The major fractions, i.e. LD1 to LD3 were present in anodic part of IEF-gram. We quantitatively expressed this different mobility of mammalian and avian forms of LD using retention factors Rf (Tab. III). A migration distance of cattle LD1 served as a reference point. It could be seen from a comparison of Rf values that avian forms of LD (of galiform origin) differed from mammalian ones by an outstanding shift of their isoelectric points, especially that of LD1, toward basic values. The total LD activity (IU) and the relative distribution of the LD isoenzyme activities (%) in normal serum of various animals are listed in Tabs I and II. A comparison of these values showed that, in contrast to mammalian serum (with the exception of the rat one), LD5 was the predominant fraction in fowl serum, followed by LD4. LD1 to LD3 occurred in low amounts with fairly similar proportions. On the other hand, most of mammalian serum revealed a reverse pattern of LD isoenzymes, i.e. predominant portion of serum activity had been concentrated in the first three anodic fractions and LD4 and LD5 had been found to be minor ones.