Features Of Carbohydrate Metabolism Research Articles

Features of carbohydrate metabolism in a patient with type 1 diabetes mellitus in subclinical hypothyroidism in the outcome of chronic autoimmune thyroiditis

Diabetes mellitus and primary hypothyroidism, in the outcome of chronic autoimmune thyroiditis, the two most common diseases in endocrinology and the practicing doctor are important not to forget about the possible association of these pathologies. This applies to patients with diabetes mellitus, both 1 and 2 types. However, the combination of these two pathologies is more common in type 1 diabetes, which is due to the autoimmune nature of these diseases. A clinical case of a patient with type 1 diabetes mellitus, which is on pump insulin therapy, is presented, which, in the background of previously selected therapy, during the last 2 months, episodes of hypoglycemia increased. In the course of the survey, primary subclinical hypothyroidism was identified, in the outcome of chronic autoimmune thyroiditis. Against the background of the achievement of euthyroidism, it was possible to achieve compensation of carbohydrate metabolism without correction of previously selected insulin therapy. The high incidence of thyroid dysfunction in patients with diabetes mellitus, and as a consequence, the deterioration in the compensation of carbohydrate metabolism, requires a systematic screening of thyroid disorders in the presence of diabetes mellitus.

Особливості вуглеводного обміну, фактори ризику та фактичний вміст вуглеводів у раціонах харчування дітей, які мешкають у несприятливих екологічних умовах

Особливості вуглеводного обміну, фактори ризику та фактичний вміст вуглеводів у раціонах харчування дітей, які мешкають у несприятливих екологічних умовах

Features of carbohydrate metabolism and incretin secretion in patients with Cushing disease and acromegaly

Aim. This study aims to analyse the rhythm and levels of incretins and neuropeptides secretion in patients with Cushing disease (CD) and acromegaly, and thus specify the pathogenesis of carbohydrate metabolism disturbances.
 Matherials and methods. In this study, 42 patients (mean age, 37.5 years) with CD and acromegaly were enrolled. All patients were newly diagnosed with CD and acromegaly, and none had a history of previous drug therapy, radiotherapy or pituitary surgery. All patients underwent OGTT, during which glucose, glucagon, GLP-1, GLP-2, GIP and ghrelin were evaluated at 0, 30 and 120 min, respectively.
 Results. During OGTT, glucose levels were not significantly different between the groups. The relevance of pre-diabetes was higher in patients with CD. In these patients, while glucagon levels were substantially higher at all cut-off points than those in controls (р = 0.001), GIP secretion was slightly lower. The acromegaly group was characterised by an inverse rhythm of GIP secretion with no peak level at 30 min. In addition, GLP-1 levels were significantly higher in patients with CD (р = 0.047). Similarly, GLP-2 levels were also significantly higher in patients with CD than in those with acromegaly and controls (p = 0.001). Finally, ghrelin levels were significantly higher in patients with CD (р = 0.013) and acromegaly (р = 0.023).
 Conclusion. More pleiotropic actions of glucocorticoids can explain the higher relevance of carbohydrate metabolism disturbances in patients with CD. This can also be explained by higher levels of glucagon secretion, which do not depend on the type of carbohydrate metabolism disorder and are stimulated by a direct action of glucocorticoids on the glucagon receptor. GIP and GLP-1 secretion in patients with CD and acromegaly are characterised by the inverse rhythm with no peak levels, implying that these hormones do not play a crucial role in the development of carbohydrate disturbances in these patients. In contrast, GLP-2 and ghrelin seem to influence and potentially regulate glucose homeostasis in patients with CD and acromegaly.

Effect of weekly physical activity frequency on weight loss in healthy overweight and obese women attending a weight loss program: a randomized controlled trial

The effect of intensity and duration of physical activity (PA) on weight loss has been well described. However, the effect of the frequency of weekly PA on weight loss is still unknown. The purpose of this study was to evaluate the effect of the frequency of weekly PA sessions while maintaining the same total activity time on weight loss during a 24-wk weight loss program. Overweight and obese women [n = 75; body mass index (BMI; in kg/m2): 27-37; age: 18-40 y] who had a normally sedentary lifestyle were randomly allocated to 1 of 2 intervention groups: a high-frequency physical activity (HF) or a low-frequency physical activity (LF) group. The HF group included 50 min/d PA, 6 d/wk (300 min/wk). The LF group included 100 min/d PA, 3 d/wk (300 min/wk). Both groups were advised to follow the same dietary weight loss program. Both groups showed a significant decrease in anthropometric measurements and significant improvements in cardiometabolic disease risk characteristics over the 24 wk of the study. Compared with the HF group, the LF group had a greater decrease in weight (mean ± SD; LF: 9.58 ± 3.77 kg; HF: 7.78 ± 2.68 kg; P = 0.028), BMI (LF: 3.62 ± 1.56; HF: 2.97 ± 1.02; P = 0.029) and waist circumference (LF: 9.36 ± 4.02 cm; HF: 7.86 ± 2.41 cm; P = 0.031). However, there were no significant differences in carbohydrate metabolism characteristics or lipid profile after the 24 wk of intervention. Weekly PA undertaken over fewer sessions of longer duration during the week could be more effective for weight loss than when undertaken as more frequent shorter sessions in overweight and obese women on a weight loss program. This may be helpful for those who are neither willing nor able to schedule time for PA almost every day to achieve weight loss. This trial was registered at www.irct.ir as IRCT201402157754N4.

Клиническая эффективность совместного применения метформина и аторвастатина у пациентов остеоартрозом с метаболическим синдромом

The purpose was to evaluate the effectiveness of combined use of the Metformin and the Atorvastatin for the correction of the metabolic syndrome in patients with osteoarthritis. The study included 70 patients with osteoarthri-tis and metabolic syndrome, who were divided into 2 groups: control and basic. In the control group, the patients received only pathogenetic treatment of osteoarthritis and anti-hypertensive therapy. Patients of the main group also received the Metformin 500 mg x 2 times and the Atorvastatin 10 mg/day. The authors monitored biochemical, anthropo-metric indicators, assessed the severity of articular syndrome by calculation of the number of tender joints and swollen joints according to the index Richie. The intensity of articular syndrome was evaluated by the visual analogue scale, the authors determined the index WOMAC and Lequesne in both groups of patients 1-3, 7-10 days, 3, 6, and 12 months. On the background of combined use of these drugs has been able to achieve significantly positive changes in the characteristics of carbohydrate metabolism, lipid spectrum of blood, anthropometric data, as well as reducing the severity of pain and the number of swollen joints in the absence of side reactions. These results confirm the clinical efficacy of combined use of the Metformin and Atorvastatin not only for the metabolic syndrome, but for the articular status in osteoarthritis.

Glycolytic Metabolism is Differentially Coupled to Proliferative Potential and Morphodynamic Capacity in RAW 264.7 and Mafb/C-Maf Deficient Macrophage Lineages

Background: Macrophages are highly specialized immune cells of different developmental origin, which occur in a continuum of diverse functional states in almost all tissues. In order to fulfil their complex role in tissue homeostasis and defence against pathogens they must be able to live with heterogeneous extrinsic nutrient conditions in tissue niches and handle variation in intrinsic metabolic demand that is determined by differentiation state, functional specialization and immune challenge. The purpose of the present study was to gain more insight in how metabolic specialization and versatility in fate and immune effector function of macrophages are coupled. Methods: In vitro phenotypic characteristics of two macrophage cell lineages of profoundly different developmental origin and polarization capacity, RAW 264.7 and Maf-DKO cells, were analysed. By use of biochemical and cell biological approaches and scanning electron microscopy, we studied the metabolic profiles of these two types of macrophages in relation to proliferative capacity, morphological appearance of cell surface and cell shape, and phagocytic activity as index of morphodynamic potential. Results: Comparison of gross features of carbohydrate metabolism, including levels of glycolytic enzymes Hexokinase (HK), Pyruvate Kinase (PK-M2), lactate dehydrogenase and nicotinamide phosphoribosyltransferase (Nampt), glucose and oxygen consumption and lactate production rates, and intracellular concentrations and redox ratios of NAD(P)(H) demonstrated that RAW 264.7 and Maf-DKO cells are conspicuously similar in that they both rely heavily on the use of glycolysis. In this respect they share many characteristics with primary macrophages. Strikingly, this uniform metabolic signature does not translate in behavioral-functional similarities as RAW 264.7 cells have a significantly higher proliferation rate, whereas Maf-DKO cells appear to be morphodynamically more active, form significantly more surface membrane protrusions and phagocytose complement opsonized particles much more efficiently. Conclusion: We conclude that the global rate of glycolysis in intermediary carbohydrate metabolism is similar for the two cell lineages, but that they can make differential use of this important pathway, either to fuel high morphodynamic activity in Maf-DKO cells, or for the sustenance of cell growth in fast proliferating RAW 264.7 cells. Our findings are in keeping with the idea that macrophages may uniformly prefer use of the rapid response time of glycolysis because this pathway provides them with the ability to meet any possible short-timescale energy demand required for immune function.

Enterococcus saccharolyticus subsp. taiwanensis subsp. nov., isolated from broccoli

A coccal strain isolated from fresh broccoli was initially identified as Enterococcus saccharolyticus; however, molecular identification and phenotypic traits did not support this identification. DNA-DNA hybridization with the type strain of E. saccharolyticus (76.4 % relatedness), DNA G+C content (35.7 mol%), phylogenetic analysis based on 16S rRNA, pheS and rpoA gene sequences, rep-PCR fingerprinting and profiles of cellular fatty acids, whole-cell proteins and enzyme activities, together with carbohydrate metabolism characteristics, indicated that this strain is distinct and represents a novel subspecies, for which the name Enterococcus saccharolyticus subsp. taiwanensis subsp. nov. is proposed. The type strain is 812(T) ( = NBRC 109476(T) = BCRC 80575(T)). Furthermore, we present an emended description of Enterococcus saccharolyticus and proposal of Enterococcus saccharolyticus subsp. saccharolyticus subsp. nov. (type strain ATCC 43076(T) = CCUG 27643(T) = CCUG 33311(T) = CIP 103246(T) = DSM 20726(T) = JCM 8734(T) = LMG 11427(T) = NBRC 100493(T) = NCIMB 702594(T)).

The influence of insulin resistance and disturbances of carbohydrate metabolism in the acute period of myocardial infarction

This work was designed to study parameters of carbohydrate metabolism and insulin resistance (IR) in patients presenting with myocardial infarction (MI) and elucidate their relation to MI complications. Special attention was given to the relationship between disturbances of carbohydrate metabolism (DCM), the clinical course of myocardial infarction in the acute and cicatrization phases, characteristics of coronary arteries in the patients with and without diabetes mellitus (groups 2 and 1 respectively). Insulin resistance was documented in 83.2% of the patients. Multiple lesions in the coronary arteries were shown to be directly related to the immunoreactive insulin (IRI) level (r=0.277; p=0.0008) and HOMA index (r=0.304; p=0.0001). They were more common in patients with IR (86%; p<0.001). The clinical course of MI was more frequently complicated by early post-infarction angina, MI relapses, and heart failure (Killip functional class II) in the patients presenting with a combination of IR and DCM than in those showing normal sensitivity to insulin regardless of the characteristics of carbohydrate metabolism. It is concluded that the detection and correction of insulin resistance and disturbances of carbohydrate metabolism are the indispensable prerequisites for the successful prevention of myocardial infarction.

PPAR-γ2 Pro12Ala polymorphism is associated with post-challenge abnormalities of glucose homeostasis in children and adolescents with obesity

The aim of the study was to investigate the association between PPAR-gamma2 Pro12Ala polymorphism and laboratory characteristics of carbohydrate metabolism in children and adolescents with obesity. In addition, serum levels of tumor necrosis factor (TNF)-alpha, and soluble form of its receptors (sTNFR1 and sTNFR2) were assessed. In a cross-sectional study, 79 obese children and adolescents of Caucasian origin were investigated. PPAR-gamma2 Pro12Ala polymorphism was determined using polymerase chain reaction--restriction fragment length polymorphism technique. Serum levels of TNF-alpha, sTNFR1 and sTNFR2 were measured by enzyme amplified sensitivity immunoassay. The minor Ala allele frequency was found to be 14.56% in our cohort. No significant differences in age, BMI, waist circumference, blood pressure, serum lipid, uric acid, TNF-alpha, sTNFR1 and sTNFR2 values were found between carriers of the Ala allele (Pro/Ala and Ala/Ala; n=21) vs. homozygous carriers of the Pro allele (Pro/Pro; n=58). However, post-challenge (120 min) plasma glucose and insulin values were significantly lower in Ala allele carriers vs. homozygous Pro allele carriers (6.56 +/- 0.26 vs. 7.36 +/- 0.25 mmol/L and 65.9 +/- 13.8 vs. 111.8 +/- 20.7 microU/mL, respectively; p < 0.05); while no significant differences were found at fasting state. The association between PPAR-gamma2 Prol2Ala polymorphism and glucose metabolism is already present in children and adolescents with obesity who might be at the very beginning of the natural course of type 2 diabetes. At this stage, higher insulin sensitivity can be detected in Ala allele carriers compared to homozygous Pro subjects at post-challenge but not in fasting state; however, the TNF-system seems not to be involved in the alteration of glucose homeostasis due to PPAR-gamma2 Pro12Ala polymorphism.

The importance of combined glycemic control in patients with type 2 diabetes mellitus

The contribution of intensive control of glycemia to the reduction of the risk of microvascular complications of type 2 diabetes mellitus is known perfectly well whereas its influence on the development of macrovascular complications remains to be clarified and remains a subject of debates. Bearing in mind that hyperglycemia is a key pathogenetic factor triggering formation of diabetic complications, it is necessary to identify characteristics of carbohydrate metabolism to be taken into account when choosing therapeutic strategies and to determine their target values. Control of the HbA1c level remains the most accessible and informative tool for the assessment of the efficiency of long-term compensation of type 2 diabetes mellitus. However, this method is not altogether free from limitations that can hamper its clinical application. The fasting glycemia level does not completely reflect the quality of DM2 treatment. There is potential relationship between high postprandial plasma glucose levels and the development of vascular complications. Also, it has been shown that variability of glucose concentration may be an important risk factor of diabetic complications. Measurement of the full range of glycemic parameters including fasting plasma glucose level, HbA1c and postprandial glycemia gives an idea of the general picture of the course of the disease necessary for the choice of the treatment strategy.

Initiation of insulin therapy for type 2 diabetes mellitus

This program is designed to identify patients in whom diabetes mellitus resists therapy with oral hypoglycemic agents (OHA) and basal insulin administration is needed to maintain the HbA1c at the desired level below 7. Data from 2895 patients (2034 women and 851 men) were available for analysis. Only 2.6% of the patients had the glycated hemoglobin (HbA1c) level within the normal values prior to the onset of therapy. The remaining ones had decompensated diabetes mellitus that required supplementation of regular OHA therapy with Lantus insulin. Characteristics of carbohydrate metabolism significantly improved and decreased to the desired values within 12 weeks after the initiation of the combined treatment without enhancement of the risk of hypoglycemia. Results of the study demonstrate beneficial effect of the early prescription of basal insulin. Administration of glargine insulin permits to rapidly and safely reach optimal parameters of carbohydrate metabolism in the majority of the patients.

The nutritional biochemistry of wool and hair follicles

AbstractThe rôle of various classes of nutrients (energy substrates, vitamins, minerals, amino acids) in the production of wool and hair from follicles, is considered for a variety of animal species. The wool and hair follicle have evolved a number of interesting features of carbohydrate metabolism including glutaminolysis, aerobic glycolysis, significant activity of the pentose phosphate pathway, and storage and mobilisation of glycogen. Presumably the necessity to continue to produce fibre despite fluctuations in the supply of oxygen and nutrients has resulted in some of these unique features, while others reflect the high level of DNA and protein synthesis occurring in the follicle. While it is considered that energy does not normally limit fibre growth, the relative contributions of aerobic and anerobic metabolism will greatly influence the amount of ATP available for follicle activity, such that energy availability may at times alter fibre growth. Alopecia and deficient fibre growth are consistent outcomes of deficiencies of biotin, riboflavin, pyridoxine, folate and pantothenic acid, but the precise rôles of these vitamins in follicle function await elucidation. Folate, in particular appears to play an important rôle in wool production, presumably reflecting its involvement in methionine metabolism. Cholecalciferol (vitamin D) significantly alters fibre growth in cultured follicles; vitamin D receptors are located in the outer root sheath, bulb, and dermal papilla of the follicle; and alopecia occurs in humans with defects in the vitamin D receptor. Retinol (vitamin A), too, appears to influence follicle function by altering keratinocyte proliferation and differentiation, with direct effects on the expression of keratin genes. The receptors for the retinoids are present in the keratogenous zone, the outer root sheath, the bulb, and the sebaceous glands. Vitamin A may also act indirectly on follicle function by influencing the activity of the insulin-like and epidermal growth factors and by altering vitamin D activity. At present there is little evidence implicating alpha-tocopherol (vitamin E) or phytylmenaquinone (vitamin K) in follicular events. Of the minerals, only copper and zinc have been shown to have direct effects on follicle function, independent of effects on food intake. Copper has direct effects on the activity of an unidentified enzyme on oxidation of thiol groups to form disulphide linkages. Wool produced by copper-deficient sheep lacks crimp, is weak and lustrous. Copper is also necessary for the activity of tyrosinase and the tyrosinase-related proteins involved in melanin synthesis. Zinc, like copper, is required for the normal keratinization of fibres but again, the precise rôle has yet to be elucidated. While the importance of amino acid supply for wool growth has long been established, there are still some unaswered questions such as; what are the effects of amino acids on fibre growth in animals other than sheep; what are the characteristics of the amino acid transport genes and proteins operating in the wool and hair follicle; and what are the specific rôles for amino acids in follicle function.

Influence of caloric intake on aging and on the response to stressors

Reducing the food intake of rodents to well below that of ad libitum fed animals increases the life span. This action, which gerontologists often refer to as the antiaging action of dietary restriction (DR), is due to the slowing of the aging processes. DR also maintains most physiological processes in a youthful state and delays the occurrence and/or slows the progression of age‐associated disease processes. This antiaging action of DR results from the reduced intake of calories. Reduction of the body fat content does not play a causal role in the antiaging action of DR, nor does reduction in the metabolic rate. Alterations in the characteristics of carbohydrate metabolism and of oxidative metabolism in response to DR have been found that are of such a nature that they could, at least in part, underlie the antiaging action. Several theories have recently been proposed in regard to the mechanisms responsible for the antiaging action of DR, but none has been tested by rigorously designed studies. Of these theories, the one that seems most promising is based on the fact that DR protects rats and mice of all ages against the damaging actions of acute stressors. This protective action against stressors may play a major role in the antiaging action of DR.

Characteristics of Carbohydrate Metabolism in Sweet Corn (sugary-1) Endosperms

Metabolic characteristics of developing sugary-l maize (Zea mays L.) endosperms were investigated. In the later stages of development (&gt;30 days postpollination), sugary-1 kernels maintained higher levels of many enzyme activities and retained more moisture than normal kernels. Higher enzyme activities were attributed to moisture retention and were not associated with any increase in dry weight accumulation. Of enzyme activities measured at 20 days postpollination, that of ADP-glucose pyrophosphorylase was higher in sugary-1 kernels than in normal, whereas total amylase, a-amylase, and pullulanase activities were lower. Experiments testing the effects of zero, one, two, and three doses of the sugary-1 gene in OH43 endosperms indicated that the sugary-1 phenotype was not expressed until three doses of the sugary-1 gene were present. Decreased activities of amylases, but not of pullulanase, were attributed to an interference in detection by phytoglycogen. Increased ADP-glucose pyrophosphorylase activity is attributed to a response by the maize endosperm cells to increased sucrose concentrations.

Glucose utilization in the surgical newborn infant receiving total parenteral nutrition

Glucose is the main source of nonprotein calories in total parenteral nutrition (TPN). However, its use has been associated with various nutritional, metabolic, and respiratory complications. The aim of this study was to determine, in the stable surgical newborn infant, the characteristics of carbohydrate metabolism, in particular the maximum oxidative threshold for intravenous glucose and the thermogenic effect of glucose. Twenty-one studies were done on 11 infants (weight 2.82 ± 0.19 kg) receiving TPN containing constant amounts of amino acids (2.5 g/kg/d) and fat (3.0 g/kg/d), and different amounts of glucose (range, 10 to 25 g/kg/d). Oxygen consumption (V̇O 2), carbon-dioxide production (V̇O 2), and resting energy expenditure (REE) were measured by indirect calorimetry. Urinary nitrogen excretion rate was measured and substrate utilization calculated from the non-protein respiratory quotient (NPRQ). There was a positive correlation between the predictor variable glucose intake and the dependent variables V̇O 2 ( r = .55; P < .05), V̇CO 2 ( r = .83; P < .0001), REE ( r = .65; P < .005), NPRQ ( r = .94; P < .0001), respiratory rate ( r = .46; P < .06), and plasma triglycerides level ( r = .67; P < .01). When glucose intake exceeded 18 g/kg/d the NPRQ was greater than 1.0, indicating glucose conversion to fat. Above this level of intake, the gradient of the correlation between the predictor variable glucose intake and the dependent variables V̇CO 2 and REE increased. From this study we conclude that: (1) Glucose intake is the principal determinant of glucose utilization and exerts an influence on the metabolism of exogenous fat. (2) Once the maximum oxidative capacity for glucose (18 g/kg/d) is reached: net fat oxidation ceases and net fat synthesis occurs; the thermogenic effect of glucose increases and the efficiency with which glucose is metabolized decreases; carbon dioxide production increases and is associated with an increased respiratory rate; and endogenous triglycerides are released into the circulation.

Dietary restriction alters characteristics of glucose fuel use.

A longitudinal study of plasma glucose and insulin concentrations in ad libitum fed and dietary restricted male F344 rats was carried out. The life span diurnal pattern of plasma glucose concentration was such that through most of the day dietary restricted rats have significantly lower plasma glucose levels than ad libitum fed rats. Throughout the life span, dietary restricted rats maintain mean 24-hour plasma glucose concentrations about 15% below those of ad libitum fed rats. Plasma insulin levels are maintained in dietary restricted rats at about 50% of the levels in ad libitum fed rats. Although plasma glucose and insulin levels are lower, dietary restricted rats use glucose fuel at the same rate per unit of metabolic mass per day as rats fed ad libitum. While these findings are consistent with the glycation hypothesis of aging and with our hypothesis that dietary restriction retards the aging processes by altering the characteristics of fuel use, they do not establish the validity of either. It is possible that this effect of dietary restriction on carbohydrate metabolism plays no role in its antiaging action. Further studies are required to define the role of these altered characteristics of carbohydrate metabolism in the aging processes.

Characteristics of carbohydrate metabolism in isolated cytotrophoblastic cells compared to whole placental tissue

Characteristics of carbohydrate metabolism in isolated cytotrophoblastic cells compared to whole placental tissue

A new mathematical approach to the metabolism of [14C]glucose, with applications to sensory ganglia of chicken embryos.

Abstract— The available models of carbohydrate metabolism are not suitable for analysis of experiments on dorsal root ganglia of chicken embryos because they assume that certain products of the pentose cycle mix freely with those of glycolysis, which appears not to be true in this tissue, and because full isotopic equilibration, needed before the start of measurements, is not achieved while the excised ganglia are reasonably fresh. Therefore, new equations were developed which assume only a steady state of relevant metabolic intermediates and make use of the process of isotopic equilibration as a source of information. It is also assumed that an initially unknown but calculable fraction of the products of each pentose cycle re‐enters the next cycle, the remainder leaking either to glycolysis or to the incubation medium. From measurements of the time course of output of labelled CO2 in the presence of [1‐14C]‐ and [6‐14C]glucose and the incorporation and release in lactate of labelled C from [l‐14C]glucose, the equations permit the estimation of many features of carbohydrate metabolism, such as the partitioning of material between the pentose cycle and glycolysis, the partitioning of CO2 output between the pentose and citric acid cycles, the partitioning of the products of glycolysis between CO2 and other destinations, such as lactate, and the degree of recycling from one pentose cycle into the next. In addition, the time course of labelled CO2 output from [2‐14C]glucose can be predicted; this, by comparison with the observed output, serves to support some variants of the basic model, while invalidating others.In dorsal root ganglia from 15‐day chicken embryos, the assumption of a metabolic steady state was supported by a constant output of labelled CO2 from [l‐14C]glucose for 15 or more hours, except for the initial period of isotopic equilibration. By use of the new equations, it is concluded that in these ganglia (a) recycling in the pentose cycle can be 100% efficient in some incubation conditions, but not in others, (b) more CO2 is released from the pentose cycle than from the citric acid cycle, (c) large, quantifiable differences exist between the utilization of the various carbon atoms of glucose, and (d) a pool of intermediates within the pentose cycle, with a time constant of about 1 h, explains a large delay observed in the output of C‐6 of glucose into CO2, which occurs with a time constant as long as 5 h under some conditions. Under conditions where recycling is complete in the pentose cycle, this cycle must operate in isolation from glycolysis, which would otherwise convert much of the output of the pentose cycle to lactate. This may explain the role of fructose‐1,6‐diphospha‐tase in the tissue, without recourse to the oft‐proposed, puzzling, and ATP‐degrading‘futile cycle’between fructose‐6‐P and fructose‐1,6‐diP.It is proposed that the new equations may be suitable for similar analyses on some, but not all, other tissues.

LSD-25 and carbohydrate metabolism

Summary The effect of LSD-25 on certain features of carbohydrate metabolism was studied in rat brains. The following results were obtained. (1) Additionin vitro of concentrations of2.5·10−5 M and 5·10−5 M LSD-25 significantly inhibited glycolysis, with greater inhibition at the higher concentration. (2) In brain examined 1 h after injection, glycolysis was observed to be significantly increased after a single dose of 4 mg/kg LSD-25. (3) Phosphorylase and hexokinase activities were unaffected by the addition of LSD-25 at a concentration of 5·10−5 Min vitro. Injection of 1.5 mg/kg LSD-25 at 12-hourly intervals for 10 days produced no observable change in glycolysis or in phosphorylase activity in brain tissue extracted 12 h after the final injection.

Special features of carbohydrate metabolism in sugar diabetes in the period of lactation

Special features of carbohydrate metabolism in sugar diabetes in the period of lactation