Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.1.1 (hexokinase)
 5,274 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The flux of glucose through the pentose phosphate pathway, important in relation to the provision of ribose 5-phosphate for nucleotide and RNA synthesis, was decreased by 70% in the diabetic rat heart in parallel with a similar decreased flux through the glycolytic route. A common factor linking the decreased flux through these alternative routes is the known fall in cardiac hexokinase; in these experiments there is a 50% decrease in Type II hexokinase (EC 2.7.1.1.) in both soluble and particulate fractions. The level of fructose 2,6-bisphosphate, a regulator of phosphofructokinase activity, is decreased by 20% in the alloxan diabetic rat heart, this may be a significant additional factor in the marked decrease in the flux of glucose through the glycolytic route in the myocardium in diabetes.
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PMID:Regulation of alternative pathways of glucose metabolism in rat heart in alloxan diabetes: changes in the pentose phosphate pathway. 636 95

The effect of adrenalectomy and corticosterone replacement on epididymal enzymes involved in obligatory steps of glycolysis and pentose phosphate pathway were studied along with serum hormonal profiles. Adrenalectomy was found to elevate serum prolactin while the gonadotropins and testosterone were unaltered. In caput epididymal tissue enzymes of the pentose phosphate pathway. Glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase activities were increased after adrenalectomy. However, in corpus epididymal tissue the key enzymes viz. hexokinase, 6-phosphofructokinase and pyruvatekinase of the glycolytic pathway were elevated leaving the pentose phosphate pathway unaffected. Adrenalectomy was also found to favour glycolysis of the epididymal spermatozoa. The possible direct effect of prolactin is discussed to explain the enzymatic changes in epididymis. Corticosterone replacement was found to maintain the enzyme activities along with serum prolactin and corticosterone at control levels. In conclusion, it is suggested that the adrenalectomy induced changes in enzyme activities could be due to the direct effect of prolactin.
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PMID:Effect of adrenalectomy and corticosterone replacement on epididymal carbohydrate metabolism--studies on mature male rats. 640 94

A pathway from glucose via sorbitol bypasses the control points of hexokinase and phosphofructokinase in glucose metabolism. It also may produce glycerol, linking the bypass to lipid synthesis. Utilization of this bypass is favored by a plentiful supply of glucose--hence, conditions under which glycolysis also is active. The bypass further involves oxidation of NADPH, so the pentose phosphate pathway and the bypass are mutually facilitative. Possible consequences in different organs under normal and pathological, especially diabetic, conditions are detailed. Enzymes with related structures (for example, sorbitol dehydrogenase and alcohol dehydrogenase, and possibly, aldehyde reductase and aldose reductase, respectively) are linked functionally by this scheme. Some enzymes of the bypass also feature in glycolysis (aldolase and alcohol dehydrogenase), and these enzymes, with the reductases involved, are proteins known to occur in different classes or multiple isozyme forms. Two of the enzymes (aldolase and alcohol dehydrogenase) both involve classes with and without a catalytic metal (zinc). The existence of parallel pathways and the occurrence of similar enzymic steps in one pathway may help to explain the abundance and multiplicity of enzymes such as reductases, aldolases, and alcohol dehydrogenases.
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PMID:Enzyme relationships in a sorbitol pathway that bypasses glycolysis and pentose phosphates in glucose metabolism. 640 81

The influence of thyroidectomy on key epididymal enzymes of the Embden-Meyerhof and pentose phosphate pathway have been studied in pubertal and adult animals in relation to the serum hormone profile. Age related differences in the response of epididymal segments were observed with respect to hexokinase activity, although the other 2 key enzymes of the Embden-Meyerhof pathway (6-PFK and PK) were suppressed in all regions of the epididymis in both pubertal and adult rats. The enzymes involved in the pentose phosphate pathway (G-6-PDH and 6-PGDH) remained unaltered. The serum hormone profile revealed that while FSH and testosterone titres were reduced, LH and Prl were unaltered. Replacement of T4 in thyroidectomized animals maintained serum hormone levels and the activities of the enzymes studied at control levels. It is inferred that thyroid hormones may be one part of a complex mechanism that controls carbohydrate metabolism in the epididymis.
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PMID:Influence of hypothyroidism on epididymal enzymes involved in carbohydrate metabolism. Studies in pubertal and adult rats. 641 30

Hexokinase, glucokinase, phosphofructokinase, glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase activity was studied in the liver and musculus quadriceps femoris of 110-day foetuses 1, 2, 3, 30 and 60-day piglets and in adult pigs. The activity of all enzymes in the tissues of newborn piglets is considerably higher than in the tissues of foetuses. The activity of hexokinase in both tissues of piglets increases in the first days after birth and lowers by the one month age. The phosphofructokinase activity in the skeletal muscles and the glucokinase one in the pig liver increase during the postnatal development. The activity of glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase in both tissues of pigs increases after birth and then decreases. Glucose metabolism in the pig liver at all stages of odontogenesis proceeds more intensively by the pentose phosphate pathway, and in the skeletal muscles--by glycolytic one.
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PMID:[Changes in the activity of various enzymes of carbohydrate metabolism in the liver and skeletal muscles of pigs during ontogenesis]. 645 66

The influence of thyroxine on some of the key enzymes involved in glycolytic and pentose phosphate pathways in the testes of pre-pubertal; pubertal and adult rats was studied. Thyroxine-induced (25 micrograms/100 g body weight) hyperthyroidism for 1 month resulted in no change in either hexokinase (EC 2.7.1.1) or 6-phosphofructokinase (EC 2.7.1.11) activity in the testes of rats in any age group studied. However, pyruvate kinase (EC 2.7.1.40) activity was reduced significantly in the pre-pubertal and pubertal rats. Both glucose-6-phosphate dehydrogenase (EC 1.1.1.49) and 6-phosphogluconate dehydrogenase (EC 1.1.1.44) activities were markedly increased after thyroxine treatment. Withdrawal of hormone treatment resulted in reversion of enzyme activities towards normal. The results suggest that thyroxine has an age-dependent, specific effect over testicular pyruvate kinase activity. Thyroid hormone may have a direct control over the pentose phosphate pathway in the testis.
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PMID:Specific effect of thyroid hormone on testicular enzymes involved in carbohydrate metabolism. II. Hyperthyroidism. 646 78

The level of fructose 2,6-bisphosphate is markedly decreased in the rat V.renal gland in diabetes, falling to 23% of the control value. There is parallel decrease in the flux of 14C-labelled glucose through the glycolytic route and tricarboxylic acid cycle. Only minimal changes in hexokinase (EC 2.7.1.1.), a 22% decrease in Type I hexokinase of the soluble fraction, were observed, highlighting the probable significant involvement of fructose 2,6-bisphosphate in the regulation of glycolysis in the adrenal. In contrast, there was evidence for a marked rise in the flux of glucose through the pentose phosphate pathway, which may be linked to enhanced corticoid synthesis in the diabetic state.
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PMID:Regulation of glucose metabolism in rat adrenal gland in alloxan-diabetes: the possible role of fructose 2,6-bisphosphate. 654 41

The possibility of alterations in the metabolism of glucose in the small intestine of C57BL/6J (ob/ob) obese-diabetic mice has been investigated. Glucose metabolism was assessed by direct measurement in vitro, and by assaying the activities of glycolytic and pentose phosphate pathway enzymes. The small intestine of 3-week-old obese mice exhibited a reduced glucose metabolism and hexokinase activity in comparison with lean controls. In adult animals there was little evidence for an effect of hyperphagia or hyperinsulinaemia on metabolism of glucose supplied from the lumen, except that the elevated pyruvate kinase activity in the intestinal mucosa of 20-week-old obese mice might have been a consequence of hyperinsulinaemia.
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PMID:Metabolism of glucose in the small intestine of lean and obese (ob/ob) mice. 663 48

The peculiarities of glucose metabolism were studied in typical representatives of coryneform bacteria, and its relation to inorganic polyphosphate metabolism was shown. The activity of the first two enzymes in the pentose pathway was found to be low. The key enzymes of glycolysis were detected, viz. fructose-1,6-diphosphate aldolase and 3-phosphoglyceraldehyde dehydrogenase. The second enzyme was more active in Nocardia sp. B-293 similar in its properties to Nocardia erythropolis as compared to the enzymes of the pentose shunt. The existence of polyphosphate glucokinase more active than ATP-dependent hexokinase is indicative of inorganic polyphosphates being involved in the metabolism of the above microorganisms.
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PMID:[Carbohydrate metabolic characteristics of coryneform bacteria]. 677 12

1. The following were measured in pieces of perirenal adipose tissue obtained from foetal lambs at about 120 days of gestation or within 3 days of term, and 9-month-old sheep: the rates of synthesis from glucose of fatty acids, acylglycerol glycerol, pyruvate and lactate; the rate of glucose oxidation to CO2 and the proportions contributed by the pentose phosphate cycle, pyruvate dehydrogenase and the tricarboxylic acid cycle; the activities of hexokinase, glucose 6-phosphate dehydrogenase, phosphofructokinase, pyruvate kinase and pyruvate dehydrogenase. 2. The total rate of glucose utilization was lower in pieces of adipose tissue from near-term lambs than 120-day foetal lambs and the pattern of glucose metabolism differed, with, for example, a much smaller proportion of glucose carbon being used for fatty acid synthesis, whereas a greater proportion of glucose oxidation occurred via the tricarboxylic acid cycle in the near-term lambs. In general, these differences in glucose metabolism were not associated with differences in the activities of the various enzymes listed above. 3. The rates of glucose utilization per fat-cell by 120-day foetal lambs and 9-month-old sheep were very similar but, again, the proportions metabolized to the various products differed. In particular, there was a smaller proportion of glucose oxidized via the pentose phosphate cycle and a greater proportion oxidized via pyruvate dehydrogenase and the tricarboxylic acid cycle in adipose tissue from foetal lambs. These differences were matched by a lower activity of glucose 6-phosphate dehydrogenase and a higher pyruvate dehydrogenase activity in fat-cells from the foetal lambs.
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PMID:Glucose metabolism and its regulation in pieces of perirenal adipose tissue from foetal lambs. 687 Aug 2


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