scholarly journals Adaptation of the small intestine during pregnancy and lactation in the rat

1979 ◽  
Vol 184 (2) ◽  
pp. 245-251 ◽  
Author(s):  
K Burdett ◽  
C Reek
Keyword(s):  
Small Intestine ◽  
Lactate Dehydrogenase ◽  
Isocitrate Dehydrogenase ◽  
Enzyme Activities ◽  
Unit Area ◽  
Mucosal Epithelium ◽  
Pregnancy And Lactation ◽  
Enzyme Change ◽  
Specific Activities ◽  
Glucose 6 Phosphate Dehydrogenase

During pregnancy and lactation in the rat the small intestine in general and the mucosal epithelium in particular gain weight. The specific activities of sucrase, lactate dehydrogenase and succinate-tetrazolium reductase remain constant and those of glucose 6-phosphate dehydrogenase and isocitrate dehydrogenase increase. There is no evidence that the reported decrease in absorption per unit area or weight of mucosal epithelium during pregnancy and lactation is due to decreases in enzyme activities within the epithelium. The pattern of enzyme change shows that the response of the gut to the stimuli of pregnancy and lactation must be a complex one, possibly involving increases in the specific activities of some enzymes.

scholarly journals Degradation of glucose-metabolizing enzymes in the rat small intestine during starvation

1973 ◽  
Vol 132 (4) ◽  
pp. 657-661 ◽  
Author(s):  
Gwyneth M. Jones ◽  
R. J. Mayer
Keyword(s):  
Small Intestine ◽  
Lactate Dehydrogenase ◽  
Pyruvate Kinase ◽  
Phosphoglycerate Kinase ◽  
Rat Small Intestine ◽  
Metabolizing Enzymes ◽  
Phosphogluconate Dehydrogenase ◽  
Degradation Rates ◽  
Glucose 6 Phosphate Dehydrogenase

1. The degradation rates and half-lives of hexokinase, 6-phosphogluconate dehydrogenase, lactate dehydrogenase, pyruvate kinase, glucose 6-phosphate dehydrogenase, phosphoglycerate kinase and aldolase were calculated from measurements of the decline in activities of these enzymes in rat small intestine during starvation. 2. The half-lives of the enzymes are: hexokinase, 5.7h; 6-phosphogluconate dehydrogenase, 7.6h; glucose 6-phosphate dehydrogenase, 6.0h; pyruvate kinase, 8.9h; lactate dehydrogenase, 8.7h; phosphoglycerate kinase, 8.7h; aldolase, 5.1h. 3. The significance of the results is discussed with respect to the regulation of enzyme concentrations in response to changes in diet.

NADP-linked dehydrogenases in secreted milk

1985 ◽  
Vol 52 (4) ◽  
pp. 501-506 ◽  
Author(s):  
Murray R. Grigor ◽  
Peter E. Hartmann
Keyword(s):  
Mammary Gland ◽  
Lactate Dehydrogenase ◽  
Malate Dehydrogenase ◽  
Isocitrate Dehydrogenase ◽  
Malic Enzyme ◽  
Prolonged Storage ◽  
Phosphogluconate Dehydrogenase ◽  
The Absolute ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Accurate Reflection

SUMMARYThe activities of glucose 6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, isocitrate dehydrogenase, malic enzyme, lactate dehydrogenase and malate dehydrogenase have been determined in secreted milk from sows, rats and rabbits. Within each species, although there was considerable variation in the absolute activities of these enzymes, the relative activities were similar to those observed for, or previously published for mammary homogenates. The only exception was milk glucose 6-phosphate dehydrogenase which tended to lose activity upon prolonged storage in the mammary gland. These results suggest that the pattern of milk enzymes can be an accurate reflection of that occurring in the mammary gland.

Response of teat enzymes of sheep and cattle to stimulation by stilboestrol and oestrogenic subterranean clover

1975 ◽  
Vol 26 (6) ◽  
pp. 1009
Author(s):  
R Smithard ◽  
ER Cole ◽  
JP Kennedy
Keyword(s):  
Enzyme Activity ◽  
Isocitrate Dehydrogenase ◽  
Enzyme Activities ◽  
Dose Range ◽  
Subterranean Clover ◽  
Control Groups ◽  
Short Term ◽  
Positive Linear Relationship ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
And Control

The activities of glucose-6-phosphate dehydrogenase (G-6-PDH), malate dehydrogenase (MDH) and isocitrate dehydrogenase (ICDH) were investigated as indicators of oestrogenic response in sheep and cattle. The activities of the enzymes were higher in teat tissue from wethers and steers injected with stilboestrol dipropionate than in control groups not receiving oestrogen. There was a positive linear relationship between teat enzyme activity and log(dose + 1) in wethers injected with stilboestrol dipropionate over the dose range 0–40 µg/day. G-6-PDH and MDH were used to detect oestrogenic responses in sheep and cattle to feed containing a high proportion of subterranean clover (Trifolium subterraneurn L.) cv. Dwalganup. The differences in mean enzyme activities between treatment and control groups were highly significant. The results indicate that in the short term, teat enzymes of cattle respond to oestrogenic feeds in a manner similar to those of sheep.

Enzyme Activities in Prickly Sida(Sida spinosa)Seeds of Different Developmental Stages

Weed Science ◽  
1978 ◽  
Vol 26 (4) ◽  
pp. 349-351 ◽  
Author(s):  
E. W. Smith ◽  
B. J. Reger ◽  
G. H. Egley
Keyword(s):  
Dehydrogenase Activity ◽  
Pentose Phosphate Pathway ◽  
Isocitrate Dehydrogenase ◽  
Enzyme Activities ◽  
Developmental Stages ◽  
Pentose Phosphate ◽  
Sida Spinosa ◽  
Prickly Sida ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Days After Anthesis

Key metabolic enzymes and germination were studied in developing and mature, dormant and nondormant prickly sida(Sida spinosaL.) seeds. Isocitrate dehydrogenase, glucose-6-phosphate dehydrogenase, fructose-1,6-diphosphatase, and phosphofructokinase activities were determined in developing and mature prickly sida seeds. Developing seeds less than 7 days after anthesis and at 17 days or greater after anthesis were unable to germinate. The 7-day-old seeds lacked all but fructose-1,6-diphosphatase activity. The 17-day-old seeds demonstrated all enzyme activities but failed to germinate because dehydration had occurred and seeds were unable to imbibe sufficient water without an afterripening period. Comparison of enzyme activities of dormant and nondormant seeds on incubation showed that only glucose-6-phosphate dehydrogenase was considerably different within the first 8 h of incubation. Nondormant seeds had considerable glucose-6-phosphate dehydrogenase activity before germination (radical protrusion at 8 h), suggesting an active pentose phosphate pathway.

scholarly journals Changes in Metabolic Enzyme Activities during Thidiazuron-induced Lateral Budbreak of Apple

HortScience ◽  
1991 ◽  
Vol 26 (2) ◽  
pp. 171-173 ◽  
Author(s):  
Shiow Y. Wang ◽  
Hong J. Jiao ◽  
Miklos Faust
Keyword(s):  
Pyruvate Kinase ◽  
Isocitrate Dehydrogenase ◽  
Enzyme Activities ◽  
Tca Cycle ◽  
Tricarboxylic Acid ◽  
Pentose Phosphate ◽  
Rapid Expansion ◽  
Metabolic Enzyme ◽  
Cycle Enzyme ◽  
Glucose 6 Phosphate Dehydrogenase

The activity of glucose-6-phosphate dehydrogenase (G6PDH), 6-phosphate gluconate dehydrogenase (6PGDH), isocitrate dehydrogenase (ICDH), pyruvate kinase (PK), and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) were studied in apple (Malus domestics Borkh.) buds during dormancy and thidiazuron-induced budbreak. When buds were dormant, the activity of the glycolytic enzymes GAPDH and PK and the tricarboxylic acid (TCA) cycle enzyme ICDH was low compared to that in nondormant buds. The activity of these enzymes increased during budbreak, peaked when buds were in the green tip stage just before the start of rapid expansion (at 8 days after thidiazuron treatment), and declined thereafter. The activity of pentose-phosphate cycle enzymes G6PDH and 6PGDH was higher in dormant buds than in nondormant buds. 6PGDH was about twice as high as G6PDH. During budbreak and resumption of growth, G6PDH and 6PGDH activity decreased.

The Effects of Acclimation and Low Temperatures on Enzyme Activities in Larvae of Ephestia kuehniella Zell. (Lep., Pyralidae)

1972 ◽  
Vol 3 (1) ◽  
pp. 12-18 ◽  
Author(s):  
Lauritz Sømme
Keyword(s):  
Oxygen Consumption ◽  
Isocitrate Dehydrogenase ◽  
Enzyme Activities ◽  
Low Temperatures ◽  
Ephestia Kuehniella ◽  
Acetylcholine Esterase ◽  
Acid Phosphatases ◽  
Phosphogluconate Dehydrogenase ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Different Levels

AbstractFollowing acclimation at 20° or 6° and exposure at -6° levels of enzyme activities were studied in larvae of Ephestia kuehniella. The activities of glucose-6-phosphate dehydrogenase, catalases, proteinases and acetylcholine esterase were all affected by the acclimation temperatures. Some enzymes, like 6-phosphogluconate dehydrogenase and acid phosphatases, showed different levels of activity after exposure at -6° depending on previous acclimation. After exposure at -6° the activities of 6-phosphogluconate dehydrogenase, acid phosphatases and acetylcholine esterase in larvae injected with glycerol were similar to those of larvae acclimated at 6°. Oxygen consumption and activities of isocitrate dehydrogenase and trehalase were not influenced by previous temperature treatments. It appears that various enzymes are affected in different ways by acclimation and exposure at low temperatures. It is suggested that a better balance of various enzyme activities are maintained at low temperatures in larvae acclimated at 6° or injected with glycerol. The results also indicate that resistance acclimation in this species is regulated by mechanisms that do not include capacity acclimation.

scholarly journals Chemostat studies on the regulation of glucose metabolism in Pseudomonas aeruginosa by citrate

1973 ◽  
Vol 132 (2) ◽  
pp. 129-140 ◽  
Author(s):  
F. M.-W. Ng ◽  
E. A. Dawes
Keyword(s):  
Growth Rate ◽  
Pseudomonas Aeruginosa ◽  
Glucose Metabolism ◽  
Glucose Concentration ◽  
Isocitrate Dehydrogenase ◽  
Glucose Medium ◽  
Metabolic Products ◽  
Induction Of Enzymes ◽  
Specific Activities ◽  
Glucose 6 Phosphate Dehydrogenase

The effect of the relative concentrations of citrate and glucose on the regulation of key enzymes of the direct oxidative, phosphorylative, Entner–Doudoroff and pentose-cycle pathways of glucose metabolism in Pseudomonas aeruginosa has been investigated in continuous culture under conditions of NH4+-limitation. For comparison isocitrate dehydrogenase and aconitase were also assayed. Measurements were made for steady-state and transient conditions and the effect of growth rate was also studied. When cells grew on 75mm-citrate the glucose concentration had to attain 6–8mm before significant induction of enzymes of glucose metabolism occurred; the specific activities increased further as the result of both raising the glucose concentration to 30mm and then subsequently lowering the citrate to 60mm and then to 45mm. The specific activities of the glucose enzymes increased immediately during the transient period between the steady states characteristic of growth on 6mm- and 8mm-glucose, the increase continuing for about two doubling times. The converse experiment of adding increasing citrate concentrations to 45mm-glucose medium revealed an immediate induction of the citrate-transport system, oxidation of citrate following the increase in citrate concentration up to 8mm. Between 8mm- and 16mm-citrate a marked repression of gluconate, glucose 6-phosphate and 6-phosphogluconate dehydrogenases and the Entner–Doudoroff enzymes occurred. Increased growth rate in citrate medium resulted in decreased specific activities of glucose 6-phosphate dehydrogenase and isocitrate dehydrogenase. Increased growth rate in citrate–glucose medium gave decreased specific activities of isocitrate dehydrogenase and aconitase whereas the activities of some of the glucose enzymes decreased initially but then increased at the highest growth rate (0.5h-1), at which a marked increase in glucose utilization occurred. These observations accord with the regulation of glucose enzymes by induction with glucose or its metabolites and repression by citrate or its metabolic products.

RAT ENDOMETRIUM ENZYMES IN 4-DAY OESTROUS CYCLE AND EARLY PREGNANCY

1977 ◽  
Vol 85 (1) ◽  
pp. 169-176 ◽  
Author(s):  
Jan Jelínek ◽  
Marta Jelínková
Keyword(s):  
Alkaline Phosphatase ◽  
Acid Phosphatase ◽  
Lactate Dehydrogenase ◽  
Early Pregnancy ◽  
Enzyme Activities ◽  
Oestrous Cycle ◽  
The Other ◽  
Endogenous Hormones ◽  
Specific Activities ◽  
The Individual

ABSTRACT The specific activities of lactate dehydrogenase (LDH) and its M-type (M-LDH), β-glucuronidase (β-GR), acid phosphatase (ACP) and alkaline phosphatase (AP) were determined. The specific activities of the enzymes (LDH, β-GR) in the myometrium were lower and their changes less pronounced than in the endometrium. We, therefore, determined the enzymes in the rat endometrium only in further experiments. All enzymes react sensitively to the changes induced in the endometrium by endogenous hormones in the course of a 4-day cycle: pro-oestrus (P) is characterized by rather low enzyme activities, oestrus (E) by a peak of LDH and M-LDH and a rise of AP. In metoestrus (M) there is a peak of β-GR, ACP and AP. Dioestrus (D) is characterized by a significant decrease in LDH and M-LDH and by elevated values of all the other enzymes. The values on the individual days of the 4–day cycle were compared with days 4–6 of pregnancy. The reason for this was that if the rats were not mated, they would, respectively, return to pro-oestrus instead of being 4 days pregnant, to oestrus instead of being 5 days pregnant, or to metoestrus instead of being 6 days pregnant. We found the following differences: on day 4 of pregnancy LDH and M-LDH were lower and ACP and AP higher than in P. On day 5 of pregnancy the LDH, M-LDH, β-GR and AP were lower than in E On day 6 of pregnancy the LDH, M-LDH, ACP and especially β-GR, were lower than in M.

scholarly journals Effect of herbicides and surfactants on enzymes of energy metabolism in European carp

2018 ◽  
Vol 8 (1) ◽  
pp. 948-952
Author(s):  
B.V. Yakovenko ◽  
O.P. Tretyak ◽  
O.B. Mekhed ◽  
O.V. Iskevych
Keyword(s):  
Lactate Dehydrogenase ◽  
Energy Metabolism ◽  
Isocitrate Dehydrogenase ◽  
Synthetic Detergent ◽  
Sodium Lauryl Sulfate ◽  
White Muscle ◽  
Lauryl Sulfate ◽  
Activity Of Enzymes ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
The Brain

<p>The effect of herbicides (2,4-D, Roundup, Senkor) and surfactant sodium lauryl sulfate (pure and as part of detergents) on enzymes of energy pathways in the scaly carp's body was studied. Gills, brain, liver and white muscle were selected for the analysis. To determine the levels of activity of enzymes in energy metabolism, lactate dehydrogenase (EC 1.1.1.27) and glucose-6-phosphate dehydrogenase (EC 1.1.1.49) in the cytoplasmic fraction and isocitrate dehydrogenase (EC 1.1.1.42) in the mitochondrial fraction were studied. The research found that sodium lauryl sulfate, both pure and in a synthetic detergent, increase the activity of enzymes in all experimental groups. Effect of herbicides was ambiguous. Under the influence of Sencor the activity of enzymes increases in all tissues. Roundup causes inhibition of enzymes in the brain, but there is an increase in the activity of enzymes in other tissues under the influence of this toxicant. The influence of 2,4-D causes increased activity of isocitrate dehydrogenase in all experimental groups, as well as the activity of lactate dehydrogenase in the brain and the liver increases, whereas in gills and white muscle it decreases. The activity of glucose-6-phosphate dehydrogenase by the impact of 2,4-D was decreased only in the liver, in other groups - was increased. The investigations may be evidence of adaptive alterations in energy metabolism aimed at the survival of fish under conditions of herbicides and surfactants toxic effects. Also increase the activity of enzymes can be related to detoxification processes occurring in the body and require additional energy consumption. The article presents the results of the study of the influence of herbicides (2,4-D, Zenkor, Roundup) and surfactant the sodium laurylsulfate (pure and as a part of the synthetic detergent) on the activity of lactate dehydrogenase, isocitrate dehydrogenase, glucose-6-phosphate dehydrogenase in the liver, gills, brain and white muscle of scaly carp (<em>Cyprinus carpio</em> L.). Human impact on water forcing fish to use various mechanisms of adaptation to the changed environmental conditions. Knowledge about the features of the receipt, distribution, accumulation of xenobiotics in organs and tissues, biochemical changes as a result of poisoning can be used to find out the mechanisms of fish's adaptation to toxicants, for identify the causes of death of hydrobionts in natural waters and to justify methods of controlling environmental pollution. The results of the research show that the influence of herbicides and surfactants causes significant changes in the processes of energy metabolism of scaly carp.</p>

Maternal influence and population differences in activities of mitochondrial and glycolytic enzymes in emergent sockeye salmon (Oncorhynchus nerka) fry

2004 ◽  
Vol 61 (7) ◽  
pp. 1225-1234 ◽  
Author(s):  
D A Patterson ◽  
H Guderley ◽  
P Bouchard ◽  
J S Macdonald ◽  
A P Farrell
Keyword(s):  
Lactate Dehydrogenase ◽  
Enzyme Activities ◽  
Sockeye Salmon ◽  
Citrate Synthase ◽  
Oncorhynchus Nerka ◽  
Whole Body ◽  
Performance Requirement ◽  
Maternal Influences ◽  
Different Populations ◽  
Specific Activities

Full-sib groups were created from two reproductively isolated sockeye salmon (Oncorhynchus nerka) populations, Weaver and Gates creeks, to test the hypotheses that prefed, emergent fry from different populations have different energetic capacities as revealed by whole-body maximal enzyme activities and that maternal influences account for a large portion of the variability in enzyme activities within fry populations. Weaver fry had higher mass-specific activities for lactate dehydrogenase, citrate synthase, and cytochrome c oxidase as well as higher protein-specific activities of lactate dehydrogenase. We ascribed these higher enzyme activities to the associated performance requirement of a more difficult prefeeding fry migration for Weaver fry. There were significant differences in mass- and protein-specific enzyme activities for all three enzymes among maternal broodlines within each population, suggesting that genetic differences existed among families. This study of maximal enzyme activities in juvenile sockeye highlights the importance of maternal influences, potential adaptive significance of differences in metabolic capacity, and the need for examining cellular physiology in an ecological perspective.

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