PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Glucose”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1979

Role of glucagon, catecholamines, and growth hormone in human glucose counterregulation. Effects of somatostatin and combined alpha- and beta-adrenergic blockade on plasma glucose recovery and glucose flux rates after insulin-induced hypoglycemia.

To further characterize mechanisms of glucose counterregulation in man, the effects of pharmacologically inducd deficiencies of glucagon, growth hormone, and catecholamines (alone and in combination) on recovery of plasma glucose from insulin-induced hypoglycemia and attendant changes in isotopically ([3-(3)H]glucose) determined glucose fluxes were studied in 13 normal subjects. In control studies, recovery of plasma glucose from hypoglycemia was primarily due to a compensatory increase in glucose production; the temporal relationship of glucagon, epinephrine, cortisol, and growth hormone responses with the compensatory increase in glucose appearance was compatible with potential participation of all these hormones in acute glucose counterregulation. Infusion of somatostatin (combined deficiency of glucagon and growth hormone) accentuated insulin-induced hypoglycemia (plasma glucose nadir: 36+/-2 ng/dl during infusion of somatostatin vs. 47+/-2 mg/dl in control studies, P < 0.01) and impaired restoration of normoglycemia (plasma glucose at min 90: 73+/-3 mg/dl at end of somatostatin infusion vs. 92+/-3 mg/dl in control studies, P<0.01). This impaired recovery of plasma glucose was due to blunting of the compensatory increase in glucose appearance since glucose disappearance was not augmented, and was attributable to suppression of glucagon secretion rather than growth hormone secretion since these effects of somatostatin were not observed during simultaneous infusion of somatostatin and glucagon whereas infusion of growth hormone along with somatostatin did not prevent the effect of somatostatin. The attenuated recovery of plasma glucose from hypoglycemia observed during somatostatin-induced glucagon deficiency was associated with plasma epinephrine levels twice those observed in control studies. Infusion of phentolamine plus propranolol (combined alpha-and beta-adrenergic blockade) had no effect on plasma glucose or glucose fluxes after insulin administration. However, infusion of somatostatin along with both phentolamine and propranolol further impaired recovery of plasma glucose from hypoglycemia compared to that observed with somatostatin alone (plasma glucose at end of infusions: 52+/-6 mg/dl for somatostatin-phentolamine-propranolol vs. 72+/-5 mg/dl for somatostatin alone, P < 0.01); this was due to further suppression of the compensatory increase in glucose appearance (maximal values: 1.93+/-0.41 mg/kg per min for somatostatin-phentolamine-propranolol vs. 2.86+/-0.32 mg/kg per min for somatostatin alone, P < 0.05). These results indicate that in man (a) restoration of normoglycemia after insulin-induced hypoglycemia is primarily due to a compensatory increase in glucose production; (b) intact glucagon secretion, but not growth hormone secretion, is necessary for normal glucose counterregulation, and (c) adrenergic mechanisms do not normally play an essential role in this process but become critical to recovery from hypoglycemia when glucagon secretion is impaired.

Adrenergic alpha-Antagonists↗
PubMed1979

Effects of insulin on glucose metabolism and glucose transport in fat cells of hormone-treated hypophysectomized rats: evidence that growth hormone restricts glucose transport.

In earlier studies we have shown that insulin does not stimulate glucose incorporation in adipocytes of hypophysectomized (hypox) rats. Basal glucose incorporation is decreased, although basal 3-O-methylglycose transport is very rapid and cannot be further stimulated by insulin. In this study we treated hypox rats with human GH, ACTH, and T3, alone or in combination, and examined the effects of insulin on glucose incorporation into fat cells and on 3-O-methylglucose transport. The results show that chronic administration of T3 alone to hypox rats partially restores glucose incorporation into fat cells and, in combination with ACTH, completely restores this incorporation. The two hormones have no effect on the glucose carrier system. The transport rate under T3 and ACTH replacement therapy continues to proceed at a maximal rate, so that basal glucose incorporation is high but not further enhanced by insulin. In contrast, administration of human GH to hypox rats does not influence glucose incorporation but has a marked effect on glucose transport. The basal glucose transport rate returns toward normal and again responds to insulin. This suggests 1) that enzyme activities responsible for the lipogenetic capacity of the fat cell are decreased in hypox rats and returned toward normal by the combined T3/ACTH treatment, and 2) that the limitation of glucose transport in the fat cell is controlled by GH. GH seems to induce a change of the glucose-carrier system; it leads to a restriction of glucose transport, which is acutely modulated by insulin.

Adipose Tissue↗
PubMed1979

Stimulation by polyamines of carbamylphosphate:glucose phosphotransferase and glucose-6-phosphate phosphohydrolase activities of multifunctional glucose-6-phosphatase.

The effects of added polyamines on carbamylphosphate (carbamyl-P):glucose phosphotransferase and glucose-6-phosphate (Glc-6-P) phosphohydrolase activities of rat hepatic D-Glc-6-P phosphohydrolase (EC 3.1.3.9) of intact and detergent-treated microsomes have been investigated. With the former preparation, in the presence of 1.4 mM phosphate substrate and 90 mM D-glucose (phosphotransferase), 1 mM spermine, spermidine, and putrescine activated Glc-6-P phosphohydrolase 67%, 57%, and 35%, respectively. Carbamyl-P:glucose phosphotransferase, under comparable conditions, was activated 57%, 34%, and 18%. NH+4 (0.25--5.0 mM) produced at best but a minor activation (0--14%), while poly(L-lysine) (Mr = 3400; degree of polymerization 16) equimolar relative to other polyamines with respect to ionized free amino groups activated the hydrolase 358% and the transferase 222%. Treatment of microsomes with the detergent deoxycholate reduced, but did not abolish, polyamine-induced activation. The stimulatory effects of polyamines persisted in the presence of excess catalase, indicating their independence from H2O2 formation; and were eliminated in the presence of Ca2+. Kinetic analysis revealed that all tested polyamines decreased the apparent Michaelis constant values for carbamyl-P and Glc-6-P, but had no effect on the Km for glucose. Poly(L-lysine) increased the V value for both Glc-6-P phosphohydrolase and apparent V values for phosphotransferase extrapolated to infinite concentrations of either carbamyl-P or glucose. The other tested polyamines elevated only this last velocity parameter. It is proposed that a major mechanism by which polyamines activate glucose-6-phosphatase-phosphotransferase is through their electrostatic interactions with phospholipids of the membrane of the endoplasmic reticulum of which this enzyme is a part. Conformational alterations thus induced may in turn affect catalytic behavior. It is suggested that polyamines, or similar positively charged peptides, might participate in the cellular regulation of synthetic and hydrolytic activities of glucose-6-phosphatase.

Ammonium Chloride↗
PubMed1976

The role of glucose limitation in the regulation of the transport of glucose, gluconate and 2-oxogluconate, and of glucose metabolism in Pseudomonas aeruginosa.

The pathway of glucose metabolism in Pseudomonas aeruginosa was regulated by the availability of glucose and related compounds. On changing from an ammonium limitation to a glucose limitation, the organism responded by adjusting its metabolism substantially from the extracellular direct oxidative pathway to the intracellular phosphorylative route. This change was achieved by repression of the transport systems for gluconate and 2-oxogluconate and of the associated enzymes for 2-oxogluconate metabolism and gluconate kinase, while increasing the levels of glucose transport, hexokinase and glucose 6-phosphate dehydrogenase. The role of gluconate, produced by the action of glucose dehydrogenase, as a major inhibitory factor for glucose transport, and the possible significance of these regulatory mechanisms to the organism in its natural environment, are discussed.

Alcohol Oxidoreductases↗
PubMed1977

Genetic evidence for the common identity of glucose-6-phosphatase, pyrophosphate-glucose phosphotransferase, carbamyl phosphate-glucose phosphotransferase and inorganic pyrophosphatase.

We demonstrate that glucose-6-phosphatase, pyrophosphate-glucose phosphotransferase, carbamyl phosphate-glucose phosphotransferase and inorganic pyrophosphatase activities are deficient in livers of patients with type I glycogen storage disease. This provides strong genetic evidence that these enzymatic activities reside in a single protein or share a common polypeptide chain.

Carbamyl Phosphate↗
PubMed1976

The effects of spontaneous obesity on insulin binding, glucose transport, and glucose oxidation of isolated rat adipocytes.

UNLABELLED: We have studied insulin, binding, glucose transport, and glucose oxidation, using large adipocytes isolated from older, fatter rats (greater than 12-mo-old, greater than 550 g), and smaller cells obtained from younger, leaner animals (4-5-wk-old, 120-160 g). At media glucose levels less than 5 mM, basal (absence of insulin) rates of glucose oxidation are comparable in both groups of cells. However, in the presence of insulin, the increase in glucose oxidation is much greater in the smaller cells. Maximally effective insulin levels could not overcome the defect in glucose oxidation by larger cells, and thus, even though studies of insulin binding demonstrated a 30-40% decrease in insulin receptors on the larger cells, it is probable that the defect in glucose oxidation is distal to the insulin receptor. Glucose transport was assessed by direct measurement of 2-deoxy glucose uptake. Basal levels of uptake were greater for the larger cells, whereas at maximally effective insulin concentrations, rates of 2-deoxy glucose uptake were the same for both groups of cells. Thus, in the presence of maximally effective levels of insulin, the apparent Km (2.3-2.7 mM) and Vmax values (2.6 and 2.7 nmol/10(5) cells per min) of 2-deoxy glucose uptake were comparable, indicating that the glucose transport system of the larger cells was intact. However, at submaximal levels of insulin, small adipocytes took up more 2-deoxy glucose than larger cells. These findings represent a rightward shift in the insulin dose-response curve in the cells from the older, fatter animals, and this is the predicted functional sequelae of the observed decrease in insulin receptors. Finally, when the amount of insulin bound was plotted as a function of 2-deoxy glucose uptake, no difference was seen between both groups of cells. This indicates that coupling between insulin receptor complexes and the glucose transport system is intact in large adipocytes, and is further evidence that a defect(s) in intracellular glucose metabolism is responsible for the decrease in glucose oxidation of adipocytes from older, fatter rats. IN CONCLUSION: (a) insulin-mediated glucose oxidation is markedly decreased in large adipocytes from older, fatter rats, and since this decrease cannot be corrected by maximally effective insulin levels, the defect is probably distal to the insulin receptor; (b) the glucose transport system is basically normal in large adipocytes; (c) insulin binding to receptors is decreased in large cells and the functional sequelae of this decrease in insulin binding i.e., a rightward shift in the insulin dose-response curve for 2-deoxy glucose uptake, was observed, and (d) since the decreased rates of insulin-mediated glucose oxidation can not be attributed to changes in insulin receptors or to changes in glucose transport, an intracellular defect in glucose metabolism is suggested.

Adipose Tissue↗
PubMed1977

Fetal and maternal blood glucose, insulin and acid base observations following maternal glucose infusion.

The aim of the present investigation was to examine the fetal and maternal blood glucose and insulin response following glucose infusion to the mother. The studies were performed on 11 primigravid patients with a gestational age of 38-40 weeks during the first stage of labor. Glucose was given intravenously by a bolus injection of 330 mg/kg body weight, followed by a glucose infusion of 27.5 mg/kg/min for 60 min. Glucose concentration, immuno-reactive insulin (IRI), pH and base excess of the maternal and fetal blood were measured before and during maternal glucose load. Maternal blood glucose rose within 10 min. up to 280.0 mg% (SD 25.9). This level could be fairly maintained throughout the experiment. The maternal glucose was after 60 min. infusion 326.5 mg% (SD 46.9). Fetal glucose concentration rose continuously from 65.8 mg% (SD 5.8) at control to 249.2 mg% (SD 23.3) after 60 min. The increase of maternal and fetal glucose was associated with an elevation of immuno-reactive insulin (IRI). The maternal insulin was 24.0 micronU/ml (SD 8.0). It was scattered over a wide range (55.4 micronU/ml-217.1 micronU/ml) after 60 min. glucose infusion. The fetal insulin was 17.0 micronU/ml (SD 5.2) at control and rose by 86.5% (SD 80.5) after 60 min. glucose load. One case of a mother with a subclinical diabetes mellitus deviated where the fetal insulin rose from 26.0 micronU/ml at control to 215.6 micronU/ml after 60 min. infusion. The increase of insulin per glucose rise was correlated to fetal body weight. During glucose infusion to the mother of both, fetal and maternal, acid base parameters remained unchanged. From these observations it may be concluded that in the human fetus insulin secretion following a single glucose load is generally low, however, it increases in cases where the maternal insulin response to glucose load is abnormal. This might be related to a chronic stimulation by glucose of the fetal pancreatic islet cells in poorly controlled diabetic and possibly prediabetic patients.

Acid-Base Equilibrium↗
PubMed1976

Effect of heart work and insulin on the incorporation of [14C]glucose into hexose phosphates, uridine diphosphate glucose and glycogen in the normal and insulin-deficient perfused rat heart under working and non-working conditions.

1. The specific radioactivities of glucose 1-phosphate, glucose 6-phosphate, fructose 6-phosphate, UDP-glucose and glycogen, derived from [14C]gluocose, were determined in the normal and insulin-deficient (streptozotocin-diabetic and anti-insulin-serum-treated) perfused non-working and working rat heart. 2. The specific radioactivities of all glucose metabolities reached a plateau after about 10 min, except that for glycogen, which increased slightly but steadily over the whole observation period of 30min. 3. The specific radio-activities of fructose 6-phosphate, UDP-glucose and glycogen were slignificantly lower in the streptozotocin-diabetic heart than in the normal heart. 4. Mechanical work in the normal rat heart increased the specific radioactivities of glucose 1-phosphate, UDP-glucose and glycogen, but had little or no effect on those of gluose 6-phosphate and fructose 6-phosphate. 5. In the normal heart insulin strongly increased the specific radioactivities of all gluocse metabolites under all conditions tested. The maximum values achieved in the normal working heart in the presence of insulin were only about 15-20% above those in the normal non-working heart in the presence of insulin for the phosphorylated intermediates and about 40% above for glycogen. 6. In the streptozotocin-diabetic heart, work restored the specific radioactivities of all glucose metabolities to about normal values. 7. In the streptozotocin-diabetic heart insulin strongly increased the specific radioactivities of the direct glycogen precursors glucose 1-phosphate and UDP-glucose; the effect of insulin on glucose 6-phosphate and fructose 6-phosphate was less marked. These results confirm previous findings that the primary metabolic lesion in diabetic heart muscle is a defect of glycogen synthesis. The specific radioactivity of glycogen itself was increased sixfold. 8. Under all conditions tested the specific radioactivity of glucose 1-phosphate was always found to be higher than that of glucose 6-phosphate. This indicated either compartmentation of a small but metabolically very active pool of glucose 6-phosphate, or the existence of a hitherto unknown pathway of metabolism in which glucose 1-phosphate is the primary reaction product. For a number of reasons the authors prefer the first explanation, which could also account for the observation that in the perfused normal working and non-working heart the specific radioactivity of fructose 6-phosphate was always found to be higher than that of glucose 6-phosphate. This difference disappeared or was reversed in the rat hearts rendered insulin-insufficent by either streptozotocin or anti-insulin treatment.

Animals↗
PubMed1979

Effects of alloxan on glucose-stimulated insulin secretion, glucose metabolism, and cyclic adenosine 3', 5'-monophosphate levels in rat isolated islets of langerhans.

Insulin secretion was stimulated and cyclic adenosine 3', 5'-monophosphate (cAMP) levels were elevated in isolated rat islets by 27.5 mmol/l glucose. Alloxan caused a dose-dependent decrease in both variables with complete obliteration of insulin release at a concentration of 1.25 mmol/l. D-glucose, in the presence or absence of extracellular calcium, or 3-0-methyl-D-glucose (both at 27.5 mmol/l) protected completely against the effects of alloxan on both glucose-induced insulin release and cAMP Levels. 3-0-Methylglucose did not stimulate insulin secretion or elevate cAMP and did not interfere with glucose-stimulated secretion or elevation of cAMP. When glucose-stimulated insulin release was abolished by alloxan, the metabolism of glucose, determined by the rate of 3H2O formation from [5-3H] glucose, was depressed by 20%. It is concluded that alloxan altered the adenylate cyclase system such that it could no longer be stimulated by glucose. Glucose-stimulated insulin secretion or elevation of cAMP did not appear essential for glucose to protect against alloxan. Protection by 3-0-methylglucose did not appear to be mediated through an alteration of cAMP metabolism. Alloxan did not inhibit glucose-induced insulin secretion by grossly altering glycolysis.

Alloxan↗
PubMed1978

Glucose load diverts hepatic gluconeogenic product from glucose to glycogen in vivo.

Intravenous or oral administration of concentrated glucose solution into fasted rats simultaneously injected with 14C-bicarbonate resulted in an inhibition of [14C]glucose release into the blood and in an accelerated [14C]glycogen formation associated with glycogen synthetase activation and phosphorylase inactivation in the liver. The specific activity of glycogen was much higher than that of blood glucose after the glucose load, indicating that glycogen originated from gluconeogenesis rather than blood glucose. These metabolic changes induced by the glucose load were not mediated by endogenous insulin because they were observed to the same extent in rats treated with anti-insulin serum. However, they were mostly, if not totally, abolished by adrenalectomy, which suppressed gluconeogenesis and glycogenesis. Glucose tolerance was markedly impaired not only by anti-insulin serum, which inhibits peripheral glucose utilization, but also by adrenalectomy, which affects hepatic metabolism. It is concluded that a glucose load diverts the final product of hepatic gluconeogenesis from blood glucose to liver glycogen; these metabolic changes in the liver are an important determinant of glucose tolerance.

Administration, Oral↗
PubMed1978

Transient repression of beta-galactosidase synthesis by glucose-6-phosphate in a mutant of Escherichia coli lacking enzyme II specific for glucose in the phosphoenolpyruvate-sugar phosphotransferase system.

The effects of glucose and glucose-6-phosphate in initiating the repression of beta-galactosidase synthesis were studied using a mutant of Escherichia coli K12 which lacks glucose-specific enzyme II of the phosphoenolpyruvate-sugar phosphotransferase system. It was found that glucose-6-phosphate causes transient repression of beta-galactosidase synthesis but glucose does not cause transient repression in this mutant. Evidence was obtained that both the presence of an active transport system for glucose-6-phosphate in the cells and glucose-6-phosphate in the medium are necessary for the initiation of transient repression. No metabolism of glucose-6-phosphate is required. Upon depletion of glucose-6-phosphate in the medium the transient repression was reversed. After the reversal the rate of enzyme synthesis was high in the cells which had been exposed to a high concentration of glucose-6-phosphate. It was concluded that the translocation of glucose-6-phosphate across the membranes is the primary event which affects both the initiation of and the recovery from the transient repression. During the transient repression the cellular content of cyclic adenosine 3',5'-monophosphate decreased significantly.

Biological Transport, Active↗
PubMed1979

Effects of electric stress on glucose metabolism, glucose-stimulated cyclic adenosine 3',5'-monophosphate accumulation and 45 Ca++ efflux in isolated pancreatic islets from rats fed with a high fat diet.

The effects of the electric stress on glucose oxidation, cyclic adenosine 3', 5'-monophosphate (AMP) accumulation and 45Ca++ efflux in response to glucose were studied in pancreatic islets isolated from rats fed on a control (C) or a high fat diet (F) for 12 weeks. The half of rats on each diet were subjected to electrical shocks in the random time schedule for 1 hr per day for the last 3 weeks of the feeding period (group C-S and F-S). The remaining rats were not given any shocks (group C-NS and F-NS). The rats in F-S group had the high levels of plasma epinephrine, dopamine and blood glucose. The basal content of cyclic AMP after 20 min of incubation with 2.8 mM glucose was decreased in islets from F-S group without affecting insulin release. After 20 min of incubation with 25 mM glucose, the cyclic AMP content in islets from F-S group, which was identical with that in F-NS group, was only 50% of that in C-S group. Insulin release in response to high glucose was significantly inhibited in islets from F-S group. In spite of a remarkable increase of cyclic AMP content in islets from C-S group, insulin release did not differ from that in C-NS group. Glucose (16.7 mM)-stimulated 45Ca++ efflux from the perfused islets was greatly inhibited by the high fat diet rather than by stress. The rate of glucose oxidation with 16.7 mM glucose was decreased in islets from F-S group. It is suggested that the decreased insulin release in response to glucose provoked by the combined effects of the feeding of a high fat diet and electric stress may be mediated by changes of the adenylate cyclase-cyclic AMP system on the plasma membrane of the B-cell or be related to changes in glucose metabolism in islets.

Adrenal Cortex↗
PubMed1977

Cerebral glucose-6-phosphatase and the movement of 2-deoxy-D-glucose across cell membranes.

Glucose-6-phosphatase (glucose-6-phosphohydrolase and its associated phosphotransferase activities) was determined in brain tissue and in several preparations derived from brain tissue. These included purified capillaries and established cell lines of neuronal or glial origin. Since it has been suggested that glucose-6-phosphatase may be involved in sugar transport, the characteristics of that process were examined in these preparations. The pattern of uptake of 2-deoxy-D-glucose in four cell lines was shown to involve transport of the analog across the cell membrane that was more rapid than the subsequent phosphorylation of the sugar in the intracellular compartment. In the remaining cell lines and in purified capillaries, phosphorylation of 2-deoxy-D-glucose was at least as rapid as uptake. No differences could be found between the cells in these two categories with respect to amount or localization of glucose-6-phosphatase, ability to phosphorylate 3-O-methyl-D-glucose, or ability to phosphorylate extracellular and intracellular 2-deoxy-D-glucose. In the course of these experiments, it was found that there was a rapid efflux of 2-deoxy-D-glucose from cells that had taken up this sugar. The efflux involves a dephosphorylation step catalyzed by intracellular phosphatase that releases free sugar in the cytoplasm. Glucose-6-phosphatase thus probably has no major role in the phosphorylation of glucose in brain cells, but acts in the more conventional sense, i.e. as a phosphohydrolase.

Animals↗
PubMed1976

Quantitative aspects of relationship between glucose 6-phosphate transport and hydrolysis for liver microsomal glucose-6-phosphatase system. Selective thermal inactivation of catalytic component in situ at acid pH.

Studies of the thermal stability of rat liver glucose-6-phosphatase (EC 3.1.3.9) were carried out to further elevate the proposal that the enzymic activity is the result of the coupling of a glucose-6-P-specific translocase and a nonspecific phosphohydrolase-phosphotransferase. Inactivation was observed when micorsomes were incubated at mild temperatures between pH 6.2 and 5.6. The rate of inactivation increased either with increasing hydrogen ion concentration or temperature. However, no inactivation was seen below 15 degrees in media as low as pH 5 or at neutral pH up to 37 degrees. The thermal stability of the enzyme may be controlled by the physical state of the membrane lipids and the degree of protonation of specific residues in the enzyme protein. Microsomes were exposed to inactivating conditions, and kinetic analyses were made of the glucose-6-P phosphohydrolase activities before and after supplementation to 0.4% sodium taurocholate. The results support the postulate and the kinetic characteristics of a given preparation of intact microsomes are determined by the relative capacities of the transport and catalytic components. Before detergent treatment, inactivation (i.e. a decrease in Vmax) was accompanied by a decrease in Km and a reduction in the fraction of latent activity, whereas only Vmax was depressed in disrupted preparations. The possibility that the inactivating treatments caused concurrent disruption of the microsomal membrane was ruled out. It is concluded that exposures to mild heat in acidic media selectively inactivate the catalytic component of the glucose-6-phosphatase system while preserving an intact permeability barrier and a functional glucose-6-P transport system. Analyses of kinetic data obtained in the present and earlier studies revealed several fundamental mathematical relationships among the kinetic constants describing the glucose-6-P phosphohydrolase activities of intact (i.e. the "system") and disrupted microsomes (i.e. the catalytic component). The quantitative relationships appear to provide a means to calculate a velocity constant (VT) and a half-saturation constant (KT) for glucose-6-P influx. The well documented, differential responses of the rat liver glucose-6-phosphatase system induced by starvation, experimental diabetes, or cortisol administration were analyzed in terms of these relationships. The possible influences of cisternal inorganic phosphate on the apparent kinetic constants of the intact system are discussed.

Animals↗
PubMed1975

Mammalian carbamyl phosphate : glucose phosphotransferase and glucose-6-phosphate phosphohydrolase: extended tissue distribution.

Carbamyl phosphate : glucose phosphotransferase and glucose-6-phosphate (Glc-6-P) phosphohydrolase activities have beeh demonstrated in pancreas, adrenals, brain, testes, spleen, and lung. Catalysis of these activities by classical multifunctional glucose-6-phosphatase (D-glucose-6-phosphate phosphohydrolase; EC 3.1.3.9) has been firmly established for the first four of these tissues on the basis of characteristic catalytic properties of the transferase pH-activity profiles, apparent Km values for carbamyl phosphate and glucose, substrate specificity, susceptibility to inhibition by molybdate, and activation by deoxycholate. Additional such activity due to non-specific acid (and alkaline) phosphatase action also is indicated at very high glucose concentrations. The possible physiological significance of the newly-elucidated presence of glucose-6-phosphatase-phosphotransferase in these various tissues, in addition to previously extensively studied liver, kidney, and mucosa of small intestine, is discussed briefly.

Adrenal Glands↗
PubMed1979

A controlled trial of glucose versus glucose and amino acids in premature infants.

A controlled study comparing two intravenous fluid regimens was performed in sick, premature infants. The regimens were isocaloric at 60 calories/kg/day, one providing glucose alone, the other glucose plus 2.5 gm/kg of amino acids. There was no difference in changes in body weight between the two groups; infants receiving glucose alone were in negative nitrogen balance; those receiving glucose plus amino acids were in positive nitrogen balance. Plasma amino acid values were compared to published, postprandial normal values. The TEAA and TAA of infants receiving amino acids were not different from normal. Values of TEAA and TAA of infants receiving glucose alone were significantly lower. Essential fatty acid deficiency developed in infants receiving amino acids but not in those receiving glucose alone. It is concluded that the glucose plus amino acid regimen results in anabolism without undue metabolic costs.

Amino Acids↗