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Biomedical subjects

E Grün

Publications and source records attributed to E Grün.

At least 37 records · Page 2Linked to original sources

[Perinatal development of glucose-6-phosphatase and fructose-1,6-diphosphatase activities in pig liver].

The activity of glucose-6-phosphatase (G6Pase) and fructose-1,6-bisphosphatase (FDPase) was determined in the homogenate of the liver of 69 pig fetuses during the last third of gestation (80th to 114th day), 47 piglets from birth to 4 weeks old (suckling period) and to slaughter pigs. G6Pase is evident in fetal liver at an early date and raises steadily during gestation. In newborn piglets, the enzyme activity increases rapidly during the first hours of life and remains at this high level during the first week of life. Afterwards the enzyme activity returns to birth level, which exists also in pigs at slaughtering. The activity of FDPase is constant during the fetal period. After birth enzyme activity rises at a lower rate than the G6Pase during the first week of life. This level remains constant during the suckling period and increases thereafter until the time of slaughtering of pigs. The role of hormones in the perinatal development of these enzymes is described. Probably, thyroxine causes the prenatal increase of the activity of both the enzymes. The rapid postnatal rise of G6Pase activity may be induced by the high level of hydrocortisone at parturition, and furthermore, glucagon may have a permissive effect.

Aging↗

[Activity of gluconeogenetic enzymes in the kidney of pigs during pre- and post-natal development].

In pig fetuses (19 of 8 dams) developed by Caesarean section the dry matter and protein content of the kidneys and their PEPCK activity remain constant during the last third (from 80th to 112th day) of gestation. After birth the dry matter content of the kidneys rises slowly, but their protein content remarkably. In the kidneys of suckling piglets (17 animals of 3 offsprings) the FDPase activity remains at the same level from birth to the 9th day of life, while in the same time the G6Pase activity rises 1.5-2 times. In the kidneys of newborn piglets the total PEPCK activity increases 3-4 times and the activity of the cytosolic enzyme 2-3 times during the first 12 hours of life. At the end of the first week of life the total PEPCK activity decreases by one-third, while the activity of the cytosolic enzyme remains stable. In the kidneys of slaughter pigs (n = 7) the dry matter content and the FDPase activity are significantly higher, the protein content and the G6Pase activity are the same as in the kidneys of piglets. The total PEPCK activity is one-half, the activity of the cytosolic enzyme one-third lower than in the kidneys of piglets. In the kidneys of adult pigs the PEPCK activity is localized to equal parts in the cytosol and in the mitochondria, but in some development stages the mitochondrial part exceeds that of the cytosol. In adult pigs the PEPCK activity of the renal cortex is 2.5-3 times higher than that of the renal medulla.

Animals↗

[Postnatal development of gluconeogenic key enzymes, phosphoenolpyruvate carboxykinase and pyruvate carboxylase, in pig liver].

Using a radiochemical method the activity of the gluconeogenic key enzymes phosphoenolpyruvate carboxykinase (PEPCK) and pyruvate carboxylase (PC) was determined in liver homogenates of 58 piglets (from birth to 10 days of life), 4 weaners and 18 fattening pigs. Simultaneously, the cytosolic PEPCK activity was estimated. In liver of newborn piglets (immediately after birth without suckling) total PEPCK activity is one half, cytosolic PEPCK activity one sixth and PC activity one half of that occurring in adult pig's liver. During regular suckling within the first 12 h of life, the total PEPCK activity of piglet liver rises slowly, however, cytosolic PEPCK activity increases 3 to 4 times and PC activity in the mitochondria twice. After the 2nd day of life the activity of both enzymes reaches a level which is kept during the whole suckling period: total PEPCK activity is 1.5 to 2-fold, cytosolic PEPCK activity is 2 to 3-fold higher, and PC activity is at the level existing at birth. In weaners cytosolic PEPCK activity further rises to the level existing in the liver of adult pigs. The PEPCK and PC activities in the liver at birth enables the piglet for gluconeogenesis, but due to the postnatal increase of enzyme activities, the prerequisites for an intensive synthesis of glucose are given only after the 2nd day of life.

Animals↗

[Perinatal development of the pyruvate metabolism-regulating enzyme in the pig liver].

The gluconeogenic enzymes phosphoenolpyruvate carboxykinase (PEPCK) and pyruvate carboxylase (PC) and the glycolytic enzyme pyruvate kinase (PK), regulating pyruvate metabolism, were determined in the livers of 71 fetuses, which were developed of 25 dams on the 80th, 100th, 106th, and 112th day of gestation (length: 115 days) by Caesarean section. For comparative purposes the same enzymes were estimated in 12 naturally born piglets immediately after delivery. During the period under examination (the last third of gestation) the total activity of PEPCK has its highest values at the 80th day, the PC and PK activity at the 100th day of gestation. The activities of all 3 enzymes decrease during the last 2 weeks of gestation until birth. The cytosolic part of PEPCK amounts to 10-15 per cent of total activity and develops in a parallel manner. In newborn piglets a further decline of the PC and total PEPCK activity can be observed, but the cytosolic PEPCK activity remains constant, and therefore its relative proportion increases to 25% of the total activity. The PK activity rises distinctly (1.5 times). The role of these enzymes in the carbohydrate metabolism of the fetus, especially in gluconeogenesis, is discussed in detail.

Animals↗

[Determination of the galactokinase activity of erythrocytes of swine of various ages].

In view of the fact that the ability of pig erythrocytes to use galactose will decrease with growing age, the galactokinase activity in pig erythrocytes of different age was determined by means of a spectrophotometrical method. A total of 5 pig fetuses (112th day of gestation) and 45 piglets at the age of 8 hours to 35 days belonging to different broods as well as 10 pigs for slaughter whose blood was collected after slaughtering out were included in the examination. In 5 piglets of one brood a progress examination was made during the suckling period. In the erythrocytes of all examined animals of different age groups the activity of the enzyme could be identified. There are great differences in the galactokinase activity of haemolysates of pig erythrocytes in different broods irrespective of their age. Therefore, an enzyme age dependence can only be recognized as a tendency from the comparison of the enzyme activities in erythrocytes of animals taken from different broods. In the erythrocyte haemolysate of 5 piglets of one brood the age dependence on galactokinase activity during the suckling period was determined in such a way that newborn piglets show a 30% higher enzyme activity than piglets at an age of 35 days. The enzyme activity in them, however, is still 1.6 times higher than in pigs for slaughtering. Thus, it may be concluded tht a postnatal decrease of galactokinase activity will occur in pig erythrocytes similarly to human erythrocytes. However, it is not responsible for a decrease of galactose utilization because no direct relations exist between both procedures. Parallel to glucose the decrease of galactose membrane permeability is assumed to play the decisive role here.

Age Factors↗

[Insulin and cortisol levels in blood plasma and adrenal gland mass in swine during the perinatal period].

The level of immunoreactive insulin activity and glucose in blood plasma of the umbilical vein was found to be lower than that in maternal venous blood plasma, in the last third of intra-uterine development, that is between the 80th and 112th day. No age-dependent differences were recordable regarding immunoreactive insulin activity in foetal blood plasma. Concentrations of glucose and immunoreactive insulin in venous blood plasma of piglets were found to rise, within 24 hours from birth, due to milk intake. Such rises were statistically significant but differed by individuals. None of the above parameters increased in fasting piglets. Cortisol in foetal blood plasma was found to be low, usually less than 5 ng/ml, on the 80th, 100th, and 106th day of intra-uterine life, but it went up between the 106th and 112th day. The highest concentrations were recorded from the oldest foetuses, 114 day of intra-uterine development. The cortisol levels in the blood plasma of the mothers of the above mentioned foetuses varied between 5 ng/ml and 70 ng/ml. Relative adrenal gland weight in animals aged 112 and 114 days was found to be significantly higher than that in foetuses aged 80, 100, and 106 days. No significant postnatal change in relative adrenal gland weight was recorded from piglets in the first nine days of life.

Adrenal Glands↗

[Thyroxine and triiodothyronine blood plasma concentrations in sows and newborn pigs].

Plasma thyroxine (T4) and triiodothyronine (T3) concentrations of 11 sows and their 56 fetuses have been measured by radioimmunoassay between 80--112 days of intrauterine development. Similar measurements were carried out in 20 piglets of 2 litters up to 24 hours of age and in sows; the latter within a period of 3 days before and 3 days after parturition. The average T3 concentration in the fetus was 0.30--0.41 ng/ml, that of T4 showed great variations between the litters. After 106 and 112 days of intrauterine development either a high (84 +/- and 159 +/- 24 ng/ml) or a low T4 concentration (18 +/- 10 and 11 +/- 5ng/ml) has been confirmed. At birth sows had a significantly lower plasma hormone concentration than the newborn piglets. After parturition the T4 concentration than the newborn piglets. After parturition the T4 concentration decreased significantly in the first 12 hours of life, while that of T3 increased significantly. In sows, pre- and intrapartal serum T4 and T3 concentrations were significantly lower than post partum.

Animals↗

[Enzyme arrangement of various tissues in swine. 1. Studies of the effect of 32 hours of fasting, administration of actinomycin D, and fasting in combination with administration of actinomycin D on crude protein level, activities of GOT, GTP, fructose-1,6-diphoaphatase as well as ATPase of liver, kidneys and semitendinous muscle in newborn piglets].

The effects of sufficient milk intake as well as of 32 hours of fasting after birth, administration of actinomycin D (intraperitoneal application of 1 mg/kg five weight), and fasting in combination with actinomycin D on the development of body and liver weights, crude protein levels in homogenate and supernatant of liver, kidneys, and M. semitendinosus as well as on the activities of certain tissue enzymes were analysed with four groups of piglets (n = 4). Fasting, administration of actinomycin, and fasting in combination with actinomycin D resulted in rapid reduction in body and liver weights, while the crude protein levels in those tissues were not affected with significance. GOT and fructose-1,6-diphosphatase activities in supernatant from liver tended to decline under fasting conditions. The ATPase activity in the homogenate of the above tissues did not change in response to differentiated treatment.

Adenosine Triphosphatases↗

[Enzyme arrangement of various tissues in swine. 3. Studies of pre- and postnatal activities of various enzymes (ATPase, GOT, GPT, leucine aminopeptidase, acid and alkaline phosphatases, aldose reductase, glucuronate reductase, sorbitol dehydrogenase) in various tissues].

The crude protein levels as well as the activities of various enzymes were studied in certain tissues of fetuses (80th through 114th days of development), piglets of different age groups, and pigs for slaughter. In most of the tissues tested the postnatal activities of Na-K-ATPase were beyond those recorded from fetuses. The highest GOT activities were recorded from the liver, myocardium, and kidneys. Activities were found to rise sizeably in some tissues after birth. The activity of GPT, too, exhibited age-dependent variations. The activity of leucine-aminopeptidase increased strongly after birth in liver and kidneys. Acid phosphatase activity was less markedly influenced by development phases. Those enzymes which are involved in the formation of fructose and glucose (aldolreductase, glucuronate-reductase, and sorbite-dehydrogenase) had their highest activities, all age-dependent, in liver and kidneys.

Acid Phosphatase↗

[Determination and postnatal development of fructokinase activity in swine liver].

Starting from the spectrophotometric method, described in ADELMAN et al., optimal reaction conditions for the measurement of fructokinase (ketohexokinase) in pig liver were systematically studied. It was necessary to increase the concentration of the substrate and further to lower the concentration of ATP for an optimal Mg: ATP-radio of 2:1. Using the optimized method fructokinase activity was determined in pig liver in relation to age, beginning from the last days of pregnancy to puberty. In liver of fetuses and newborn piglets during the first two days of life no or only a minute activity of the fructokinase was recorded. Therefore, the high level of fructose in fetal blood results from the inability of the fetus to metabolize fructose synthezised in the placenta or the fetal organs. At the end of the first week of life the activity of fructokinase was 10 times, after the second week 15-20 times higher than at birth. This high level remains constant during the suckling period and after weaning. For this reason, piglets after the first week of life are able to metabolize fructose and after the third week to form glucose and to release it into circulation. In adult pigs the activity of fructokinase in the liver decreases slightly. It corresponds-as in rat and human-to the elimination rate of experimentally applied fructose from the circulation. Therefore, this enzyme even in pigs is of significant importance for the utilization of fructose.

Aging↗

[Radiochemical method for the determination of the activity of the gluconeogenetic key enzymes pyruvate carboxylase and phosphoenolpyruvate carboxykinase in swine livers].

Described in this paper is a technique for the determination of pyruvate carboxylase and phosphoenolpyruvate carboxykinase, two key enzymes of gluconeogenesis in swine liver. The technique is based on measurement of radioactively labelled carbon incorporated in the common metabolite, oxalacetate. The optimum measuring conditions to establish the enzymes in liver homogenate and supernatant are reported and compared with data given by other authors. The found parameters of kinetic properties were in good agreement with the findings obtained from purified enzymes from swine liver.

Animals↗

[Determination of enzyme activities in the synovial fluid of farm animals].

Reported in this paper are methods for spectrophotometric determination of the activities of lactatedehydrogenase (LDH) and aspartate-aminotransferase (AspAT) and for colorimetric determination of the activity of N-acetyl-beta-glucosaminidase (NAG) in the synovial fluid of farm animals. Optimum conditions are suggested, as a result of these studies, for reactions of those enzymes in synovial fluid. The behaviours of these enzymes in synovial fluid were compared to those in the blood serum of domestic animals and man and exhibited close agreement. The test-kits at present commercially available for applications in human medicine and used in the determination of LDH and AspAT activities are suitable also for the determination of enzyme activities in synovial fluid. Enzymes in synovial fluid are highly responsive and, even smallest amounts of synovial fluid, therefore, are sufficient for positive findings in laboratory diagnosis.

Acetylglucosaminidase↗

[Occurrence of various enzymes in synovial fluid of cattle and swine].

The activities of lactate dehydrogenase (LDH), fructose-1.6-diphosphate aldolase (ALD), aspartate aminotransferase (AspAT), alkaline phosphatase (AP), and N-acetyl-beta-glucosaminidase (NAG) were determined on the basis of 75 synovia samples taken from the tarsal joints (Art. talocruralis) of 41 cattle for slaughter of different sexes and aged between one and 13 years as well as on the basis of 56 synovia samples taken from the knee joints (Art. femoropatellaris), tarsal joints (Art. talocruralis), and carpal joints (Art. intercarpicus) of 20 fattening pigs. Both the general condition and cell content of synovial fluid in clinically intact joints are described. The activities of ALD and AspAT (less than 15 IU/l), LDH (less than 200 IU/l), and NAG (less than 6,000 IU/l) in synovial fluid of cattle were much lower than those in blood serum of the same species. They were normally distributed. AP activity (less than 150 IU/l) in synovial fluid, however, was higher by several factors as compared to activity in blblished. In swine synovial AspAT and AP activities were just as high as in blood serum, while LDH activities were higher by 1.5 times. Major NAG activity was observed, as well. All enzyme activities were characterised by normal distribution. All five LDH isoenzymes but only one AP isoenzyme were established. The above data were compared with findings reported by other authors, and the comparison showed these results as being characteristic of synovial enzyme activities in clinically intact joints of the two species under review.

Acetylglucosaminidase↗

[Determination, proprerties and postnatal development of galactokinase in the swine liver].

1. Starting from the spectrophotometric method of Ballard optimal reaction conditions for measurements of galactokinase in piglet liver were systematically studied. These are (final conc. in the test): 100 mM triethanolamine-HCl buffer, 33 mM KCl, 16.5 mM NaF (inhibiting ATPase), 5 mM cysteine hydrochloride, 0.33 mM NADH2, 1 U pyruvate kinase and lactic dehydrogenase, 0.5 mM phosphoenolpyruvate, 1.5 mM galactose, 0.5 mM ATP and 1 mM MgCl2, final pH 7.5. 2. An optimal substrate concentration, a Mg: ATP-ratio of 2:1, pH-stability and addition of activators are important for the determination of galactokinase activity in the supernatant fraction of pig liver. 3. Using the optimized method galactokinase activity of pig liver in dependence on age, with particular reference to the perinatal period, was determined. 4. Galactokinase activity of liver of newborn piglets is 7 times that of adult pigs. In the suckling period the activity remains relatively constant at this high level and decreases remarkably immediately after weaning. 5. Galactokinase of liver of newborn piglets differs in kinetic properties (lower Km of ATP, higher maximal reaction velocity) from the enzyme of adult pigs, which is still insufficient to make sure the existence of two different forms of the enzyme.

Age Factors↗

[Effect of the type of extraction solution and length of storage on the distribution of lactate dehydrogenase isoenzymes in piglet liver homogenate].

Type of extraction solution applied to preparation of homogenate of piglet liver is of negligible importance, if immediately follows electrophoretic separation of tissue material. --Storage of liver homogenates in frozen state over 30 days involves insignificant changes of distribution of LD isoenzymes in 0.25 M sucrose, distinct changes in 0.1 M Tris-buffer, pH 7,5, and important ones in mercaptoaethanol-containing extraction solution, applied to preparation of tissue homogenates.

Animals↗

[Lactate dehydrogenase (LDH) and isoenzymes in pig liver during postnatal development].

1. LDH-activity in the liver of newborn piglets is 4 times that of adult pig sliver and remains relatively constant at this level during the first 3 weeks of life. 2. 90% of LDH is localized in the cytosolic compartment of the liver, independent of age of pigs. 3. In the liver of newborn piglets the isoenzymes LDH-3 and LDH-4 includes the main part of LDH-activity. The typical distribution of LDH isoenzymes in the liver of adult pigs (LDH-3 greater than LDH-2 greater than LDH-1 greater than LDH-4 greater than LDH-5) is already reached in 6-day-old piglets. Afterwards there follows only a decrease of LDH-1. Therefore, during postnatal development a directed shift from M- to H-type of isoenzyme distribution is observed.

Aging↗