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

Detailed histochemical studies have been conducted on the distribution of hexokinase, amylophosphorylase, aldolase, lactic dehydrogenase, succinic dehydrogenase and glucose-6-phosphate dehydrogenase in every component of the locus ceruleus, nucleus tractus mesencephalicus n. trigemini, nucleus dorsalis n. vagi and nucleus n. hypoglossi of the wistar strain rats. The locus ceruleus and nucleus dorsalis n. vagi which are considered to be belong to "exceptional nuclei" showed mild activity in the nerve cell bodies and strong activity in the surrounding glia cell for the hexokinase reaction. But, the nucleus tractus mesencephalicus n. trigemini and nucleus n. hypoglossi considered to be "usual nuclei" revealed strong activity in the nerve cell bodies and glia cells for the hexokinase reaction, however, glia cells did not show the tendency to surround the nerve cells in these nuclei. On the basis of the present findings, the glia cells may get their energy source from glucose in the circulating blood, and they may be energy donators to the nerve cells in the "exceptional nuclei" whereas the nerve cells may get their energy source directly from glucose in the circulating blood in the "usual nuclei". The former 2 nuclei showed low level activity of succinic dehydrogenase. These findings may indicate that the locus ceruleus and nucleus dorsalis n. vagi belong to the conception "exceptional nuclei" in this respect. However, the Embden-Meyerhof-Parnas (EMP) pathway was dominant in the locus ceruleus, while the WARBURG-DICKENS pathway (hexose monophosphate shunt = HMP shunt) was dominant in the nucleus dorsalis n. vagi in the present study. This descrepancy may strongly suggest that the locus ceruleus is distinctly different from the nucleus dorsalis n. vagi concerning the carbohydrate metabolism, though both nuclei are involved on the same conception "exceptional nuclei". The latter 2 nuclei (the nucleus tractus mesencephalicus n. trigemini and the nucleus n. hypoglossi) considered to be "usual nuclei" in 3 ways as that nerve cells get energy source directly from glucose in the circulating blood, that the 2 nuclei are equipped with enzymes involved in the EMP pathway and the HMP shunt to the same degree, and that they are rich in the tricarboxylic acid (TCA) cycle. The nucleus tractus mesencephalicus n. trigemini revealed considerably variable reactions for the hexokinase, aldolase, glucose-6-phosphate dehydrogenase and lactic dehydrogenase in the present study.
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PMID:Histochemical studies on the distribution of some enzymes concerned with carbohydrate metabolism in the locus ceruleus, nucleus tractus mesencephalicus n. trigemini, nucleus dorsalis n. vagi and nucleus n. hypoglossi of the rat. 80 76

Effects of prolactin (PRL), bromocriptine (Br), testosterone propionate (TP), dihydrotestosterone (DHT) and the combinations of these androgens with PRL/Br on the specific activities of caudal and cranial prostatic cellular enzymes involved in carbohydrate metabolism in castrated mature bonnet monkeys have been studied. Castration decreased all the enzymes studied such as hexokinase (HK), 6-phosphofructokinase (6-PFK), glyceraldehyde-3-phosphate dehydrogenase (G-3-PD), pyruvate kinase (PK), glucose-6-phosphate dehydrogenase (G-6-PD) and 6-phosphogluconate dehydrogenase (6-PGD) in the cranial and caudal prostates. PRL elevated the activities of all the enzymes above normal except G-3-PD of cranial lobe. In the caudal lobe, PRL brought back the activities of HK, PFK, PK, G-6-PD to normal and 6-PGD above normal except G-3-PD. TP/DHT treatment increased all the enzymes in both the lobes. PRL given along with TP/DHT further enhanced the androgen action with regard to HK, PK, G-6-PD and 6-PGD of cranial and PFK, G-3-PD, PK, G-6-PD and 6-PGD of caudal lobe. Br treatment did not produce any alteration of these enzymes in both the lobes. In the cranial lobe, during Br+TP/DHT treatment, the stimulating effects of androgen were unaffected on all the enzymes except PK. On the other hand in the caudal, the stimulatory effects of androgens were affected and the activities of HK, PFK, PK and 6-PGD were significantly decreased. The present results suggest that PRL has a direct as well as a synergistic action with androgens on enzymes of EMP and HMP shunt in the prostates of monkeys.
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PMID:Effects of prolactin and androgens on enzymes of carbohydrate metabolism in prostate of castrated bonnet monkeys Macaca radiata (Geoffroy). 138 11

Erythrocytes were separated by age using a combination of density centrifugation and counterflow centrifugation and tested for basal activity of the hexose monophosphate shunt (HMP-shunt) as well as the methylene blue-stimulated maximal capacity by measuring CO2 production. No significant differences were found in basal HMP-shunt activity, but the maximal methylene blue-stimulated activity of old erythrocytes reached only half of the activity of the total cell population. The maximal HMP-shunt activity showed a significant correlation with hexokinase activity, but not with glucose-6-phosphate dehydrogenase activity in all but the youngest cells. The sensitivity to oxidative stress was tested by measuring the kinetics of pyruvate kinase isolated from erythrocytes incubated in presence and absence of methylene blue. Pyruvate kinase kinetics were affected more in the old cell population than in the total cell population: the K0.5 for phosphoenol-pyruvate increased four times in the unseparated cells and eight times in old cells.
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PMID:Hexose monophosphate shunt activity in erythrocytes related to cell age. 261 18

Human erythrocytes overloaded with homogeneous human hexokinase (up to 15-times the activity of normal RBC) show almost unmodified rates of glucose metabolized in the HMP, however hexokinase-loaded RBC are able to metabolize 1.5 fold more glucose than controls through the HMP when an oxidizing agent like methylene blue (5 to 100 microM) is present. Similarly, RBC loaded with inactivating anti-hexokinase IgG (12 +/- 3% residual hexokinase activity) show HMP rates unchanged under resting conditions, but only 12% of the HMP rate found in normal controls under oxidative stress. These data provide clear evidence that the HMP rate under conditions of oxidative stress is controlled by hexokinase activity and suggest that RBC from patients with hexokinase deficiency are not able to increase the HMP rate under oxidative stress like erythrocytes from individuals with G6PD deficiency.
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PMID:Role of hexokinase in the regulation of erythrocyte hexose monophosphate pathway under oxidative stress. 341 98

Erythrocytes of individuals with increased (+ 50%) or reduced (-35%) hexokinase activity contain respectively 70 and 17 nmole/ml RBC of glucose-6-phosphate (normal concentration 30 +/- 5nmole/ml RBC) and show comparable rates of the HMP (60 +/- 5nmole/hr/ml RBC). Similarly, in RBC of different ages, obtained by density gradient ultracentrifugation, the glucose-6-phosphate concentration range from 57 (young cells) to 18 (old cells) nmole/ml RBC but the rate at which glucose is utilized in the HMP is unchanged. These data exclude a regulatory role of glucose 6-phosphate in the HMP even if its concentration is under that required for maximal G6PD activity.
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PMID:Relationship between the rate of erythrocyte hexose monophosphate pathway and the glucose 6-phosphate concentration. 650 92