Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:2.7.1.1 (hexokinase)
5,274 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

It is shown in experiments is vivo that development of experimental metabolic alkalosis in rats is followed by changes in redox processes in the eye retina and tunic. For the first two months of the experiment the number of sulphydryl group decreases, while that of disulphide ones of water-soluble proteins and low-molecular compounds increases. The amount of oxidized metabolites of glycolysis and of a cycle of tricarboxylic acids (pyruvate, oxaloacetate, alpha-ketoglutarate) increases relative to the reduced ones (lactate, isocitrate, malate), as well as activities of hexokinase, pyruvate kinase, NAD-dependent malate dehydrogenase, while activities of fructose diphosphatase, glucoso-6-phosphate dehydrogenase, glutathione peroxidase and glutathione reductase fall. The content of malonic dialdehyde increases. 90 days later disorders of certain compensatory mechanisms of the metabolic system of alkalosis regulation probably occurred in the eye retina and tunic tissues: hexokinase and pyruvate kinase activity fell to the control values, while that of NAD-dependent malate dehydrogenase--below the control level; the content of lactate increased. Activity of glutathione-dependent enzymes remained low and the amount of malonic dialdehyde grew much more than in the previous terms.
...
PMID:[Redox processes in the retina and tunic tissues of the rat eye in experimental alkalosis]. 144 Sep 68

Enzyme activities were determined quantitatively in individual rat oocytes to study their energy metabolism during maturation. Low hexokinase activity and high activities of lactate dehydrogenase and enzymes in the phosphate pathway, i.e., glucose 6-P and 6-P gluconate dehydrogenases, were characteristic of immature oocytes. Hexokinase may be a rate-limiting enzyme that enables oocytes to use glucose as an energy source. During maturation, the activities of hexokinase, phosphofructokinase, and malate dehydrogenase increased significantly, suggesting that the glycolytic pathway, as well as the tricarboxylic acid cycle, developed as the first meiotic division proceeded. In contrast, the activities of glucose 6-P and 6-P gluconate dehydrogenases decreased in maturing oocytes. The observation that the enzyme pattern in mature oocytes resembles more closely that in somatic cells appears to be significant, especially in light of previous studies showing this developmental trend in preimplantation embryos.
...
PMID:Determination of enzyme activities of energy metabolism in the maturing rat oocyte. 144

Renal clear cell tubules and clear/acidophilic cell tumors were induced in male Sprague-Dawley rats by 7 weeks oral administration (stop model) of N-nitrosomorpholine (NNM) at a concentration of 12 mg/100 ml in the drinking water. Twelve, 23 and 34 weeks after withdrawal of NNM serial cryostat sections of the kidneys were histochemically analyzed for the following parameters: glucose transporter proteins (GLUT1, GLUT2), glycogen content and the activities of glycogen synthase (SYN), glycogen phosphorylase (PHO), glucose-6-phosphatase (G6Pase), glucose-6-phosphate dehydrogenase (G6PDH), hexokinase (HK), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), pyruvate kinase (PK), succinate dehydrogenase (SDH), malate dehydrogenase (MDH), alkaline phosphatase (ALP), acid phosphatase (ACP) and gamma-glutamyltransferase (GGT). Clear cell (glycogenotic) tubules first appeared at 23 weeks, and clear/acidophilic cell tumors at 34 weeks after withdrawal of the carcinogen. G6Pase, ALP, GGT and GLUT2 were absent in clear cell tubules, clear/acidophilic cell tubules, and clear/acidophilic cell tumors indicating a sequential origin of all these types of lesions from the collecting duct system, in line with previous morphological findings. In comparison to the collecting duct epithelium, glycogenotic tubules demonstrated an increased activity of PHO and reduced activities of glycolytic and mitochondrial enzymes, which were accompanied by a strongly reduced expression of GLUT1. Moderately increased activities of glycolytic and mitochondrial enzymes were observed in the clear cells of clear/acidophilic cell tubules and tumors compared with those in glycogenotic tubules. They had slightly increased activities of the glycolytic enzymes GAPDH and PK compared with normal collecting duct epithelium, while most of them were nearly lacking in GLUT1. Our findings suggest that glycogen storage is not due to an increased uptake of glucose from the blood, but results from a disturbance in intracellular flux of metabolites. The development of clear cell tubules from the normal collecting duct epithelium is accompanied by a markedly decreased expression of GLUT1 along with a reduction in glycolytic and mitochondrial enzymes. This reduction of enzyme activities is replaced by an increase in enzyme activities in clear/acidophilic cell tumors indicating a fundamental shift in carbohydrate metabolism during progression from preneoplastic to neoplastic lesions.
...
PMID:Sequential changes in glycogen content, expression of glucose transporters and enzymic patterns during development of clear/acidophilic cell tumors in rat kidney. 147 41

The organ specificity of creatine kinase, esterase, isocitrate dehydrogenase lactate dehydrogenase, nucleoside phosphorylase, adenylate kinase, hexokinase, malate dehydrogenase, malic enzyme, glucose-6-phosphate dehydrogenase of black-white cattle has been studied. Esterases, creatine kinase, adenylate kinase, hexokinase and glucose-6-phosphate dehydrogenase have a very wide spectrum of the organ variabilities. Liver and heart have the largest specificity of enzymes activity. Some peculiarities of isozyme spectrum are found in ovaries and spleen.
...
PMID:[Regularities of organ-specific expression of enzyme systems in cattle]. 148 Dec 59

The activities of enzymes related to energy metabolism in the gastrocnemius and soleus muscles in young-adult (4 months), mature (12 months), and senescent (24 months) rats were compared after continuous (72 consecutive h) exposure to normobaric hypoxia or normoxia after the vasodilator naftidrofuryl or saline solution had been given intraperitoneally for 30 consecutive days. The maximum rats (Vmax) of the following enzyme activities in the crude extract and/or the crude mitochondrial fraction of each muscle specimen were evaluated for: the anaerobic glycolytic pathway (hexokinase, phosphofructokinase, pyruvate kinase, and lactate dehydrogenase), the tricarboxylic acid cycle (citrate synthase, and malate dehydrogenase), the electron transfer chain (cytochrome oxidase), and the NAD+/NADH redox state (total NADH cytochrome c reductase). The significance of differences between the enzyme activities at different ages or under different experimental conditions in the two tissue preparations of the two muscles were determined by ANOVA. MCA and ETA2 were used to evaluate the net effects of the experimental conditions. First, aging did not seem to affect the soleus and gastrocnemius muscles in the same way. In the gastrocnemius muscle, the major changes were seen in enzymes of the glycolytic pathway, in the crude extracts. In the soleus muscle, the more striking changes in enzyme activities as a function of aging were found in the crude mitochondrial fraction. We also found that hypoxia caused more important changes in 12-month-old rats than in those of other ages (especially the enzyme activities of the gastrocnemius muscle). Naftidrofuryl modified the effects of hypoxia only sometimes and further investigations are necessary before we can draw any conclusions about the pharmacological activity of naftidrofuryl in hypoxia.
...
PMID:Effects of hypoxia and pharmacological treatment on enzyme activities in skeletal muscle of rats of different ages. 164 27

The possible physiological role of estrogen in the regulation of energy metabolism of epididymis and vas deferens of rhesus monkey was investigated. A few selected key enzymes of glycolysis (hexokinase, phosphofructokinase and pyruvate kinase) and TCA cycle (succinate dehydrogenase and malate dehydrogenase) were measured in these two organs of (a) castrated estrogen treated, (b) castrated estrogen + dihydrotestosterone (DHT) treated animals and compared with those in castrated and castrated + DHT treated animals. Results reveal that DHT stimulated the activities of all these enzymes whereas estrogen failed to stimulate any of the enzymes in castrated animals. However, estrogen in combination with DHT caused a marked stimulation of the enzymes and the response of the epididymis and vas deferens to combination treatment was significantly more than that caused by DHT alone. The results suggest that circulating estrogen in male has a physiological role and acts synergistically with androgen in regulating accessory sex organ function.
...
PMID:Androgen-estrogen synergy in the regulation of energy metabolism in epididymis and vas deferens of rhesus monkey. 181 87

Studies have been made on the activity of hexokinase, phosphofructokinase, glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, malate dehydrogenase and isocitrate dehydrogenase, as well as on the intensity of in vitro oxidation of [U-14C]-glucose and [U-14C]-palmitate (together with in vivo lipid synthesis from these compounds) in porcine skeletal muscles during pre- and postnatal periods of life. It was shown that active utilization of glucose in oxidative metabolism and lipid synthesis is possible during the transition from prenatal to neonatal period. The increase in the rate of oxidation of fatty acids in skeletal muscles of piglets, in contrast to other animals, does not inhibit carbohydrate utilization.
...
PMID:[Carbohydrate and lipid metabolism in swine skeletal muscle in the pre- and neonatal periods]. 192 52

The purpose of this work was to evaluate the biochemical changes in the myocardial cell using cardioplegia supplemented with creatine phosphate (CP). Many previous studies have demonstrated the beneficial effect of CP on the ischemic myocardium and its mechanism of action has been assumed to be mainly extracellular. Based on the assumption that CP could also exert some influence on myocardial cellular metabolism, this investigation was carried out. Forty patients undergoing mitral valve replacement were divided into two groups: group 1 was treated with standard cardioplegic solution, and group 2 was treated with cardioplegic solution enriched with CP at a concentration of 10 mmol/L. Samples of papillary muscle, obtained from the removed valve, were studied by means of biochemical methods in order to assess the enzyme activities and the metabolites of the different biochemical pathways related to energy metabolism in the myocardial cell. One papillary muscle sample was used to determine enzyme activities spectrophotometrically; another was used to evaluate metabolite concentrations by spectrophotometric or spectrophotofluorimetric methods. The rate of spontaneous functional recovery after rewarming and weaning from cardiopulmonary bypass (CPB) also was evaluated. In group 2, the Vmax of enzymatic activities was significantly greater (hexokinase, malate dehydrogenase, glutamate dehydrogenase, total NADH cytochrome c reductase) and a better functional state of the heart was observed after CPB. On the basis of the clinical and biochemical data, it is concluded that the myocardium was better preserved when CP was added to the cardioplegic solution. Therefore, the results suggest a possible interaction of exogenous CP with cellular metabolism.
...
PMID:Biochemical changes induced in the myocardial cell during cardioplegic arrest supplemented with creatine phosphate. 193 52

Eleven enzymes were measured in individual fibers of soleus and tibialis anterior (TA) muscles from two flight and two control (synchronous) animals. There were five enzymes of glycogenolytic metabolism: phosphorylase, glucose-6-phosphate isomerase, glycerol-3-phosphate dehydrogenase, pyruvate kinase, and lactate dehydrogenase (group GLY); five of oxidative metabolism: citrate synthase, malate dehydrogenase, beta-hydroxyacyl-CoA dehydrogenase, 3-ketoacid CoA-transferase, and mitochondrial thiolase (group OX); and hexokinase, subserving both groups. Fiber size (dry weight per unit length) was reduced about 35% in both muscles. On a dry weight basis, hexokinase levels were increased 100% or more in flight fibers from both soleus and TA. Group OX enzymes increased 56-193% in TA without significant change in soleus. Group GLY enzymes increased an average of 28% in soleus fibers but underwent, if anything, a modest decrease (20%) in TA fibers. These changes in composition of TA fibers were those anticipated for a conversion of about half of the originally predominant fast glycolytic fibers into fast oxidative glycolytic fibers. Calculation on the basis of fiber length, rather than dry weight, gave an estimate of absolute enzyme changes: hexokinase was still calculated to have increased in both soleus and TA fibers, but only by 50 and 25%, respectively. Three of the OX enzymes were, on this basis, unchanged in TA fibers, but 3-ketoacid CoA-transferase and thiolase had still nearly doubled, whereas TA GLY enzymes had fallen about 40%. In soleus fibers, absolute levels of OX enzymes had decreased an average of 25% and GLY enzymes were marginally decreased.
...
PMID:Effect of microgravity on metabolic enzymes of individual muscle fibers. 196 37

It is well known that brain function is critically dependent upon energy metabolism and that the brain has a relatively high metabolic rate. Experiments using intact brain preparations do not provide information about metabolism in the different cell types that constitute brain tissue. Progress in primary culture techniques has facilitated biochemical investigations and analysis of the metabolic pathways prevailing in specific cerebral cell types. We found that, in the presence of pyruvate or succinate as the substrate, oxygen consumption by neurons grown in culture was always higher than that by glial cells. The relatively low values of hexokinase, malate dehydrogenase and glutamate dehydrogenase activities observed in glial cells and, in contrast, the high levels of lactate dehydrogenase and enolase activities may be the result of a less aerobic metabolism prevailing in this type of brain cell, compared to neurons. On the other hand, the predominance of the aerobic, lactate dehydrogenase, isoenzymatic form in neurons can be associated with a more aerobic metabolism in this type of cell. In the case of severe hypoxia, we observed that astrocytes were the most damaged cells. An increased lactate dehydrogenase level with a modification of its isoenzymatic profile and a decreased glutamine synthetase activity under hypoxic conditions indicated severe derangement of important biochemical functions within the astrocytes. By antagonizing some of these changes, almitrine and raubasine (both present in Duxil) seem to exert some protective effect. One may consider that, among the different cell types present in brain tissue, astroglial cells may represent a target particularly sensitive to hypoxia-induced injury.
...
PMID:[Neuronal and astrocytic plasticity: metabolic aspects]. 208 81


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>

---