Increase In Blood Glucose Concentration Research Articles

Metyrapone effects on systemic and cerebral energy metabolism

Metyrapone is a cytochrome P450 inhibitor that protects against ischemia- and excitotoxicity-induced brain damages in rodents. This study examines whether metyrapone would act on energy metabolism in a manner congruent with its neuroprotective effect. In a first investigation, the rats instrumented with telemetric devices measuring abdominal temperature, received i.p. injection of either metyrapone or saline. One hour after injection, their blood and hippocampus were sampled. Hippocampus metabolite concentrations were measured using 1H high-resolution magic angle spinning-magnetic resonance spectroscopy (1H HRMAS-MRS). The hippocampus levels in phosphorylated mammalian target of rapamycin (mTOR) and adenosine monophosphate-activated protein kinase (AMPK) were measured by Western Blot analysis and those of c-fos and HSP70-2 mRNA were quantified by RT-PCR. In a second investigation, the rats received the same treatment and were sacrificed 1h after. The functioning of mitochondria was immediately studied on their whole brain. Metyrapone provoked a slight hypothermia which was correlated to the increase in blood glucose concentration. Metyrapone also increased blood lactate concentrations without modifying hippocampus lactate content. In the hippocampus, metyrapone decreased γ-aminobutyric acid (GABA) and glutamate levels but increased glutamine and N-acetyl-aspartate contents (NAA). Phosphorylated mTOR and AMPK and the c-fos and HSP70-2 mRNA levels were similar between treatment groups. Metyrapone did not modify blood corticosterone levels. Mitochondrial oxygen consumption was similar in both groups whatever the substrate used. These metabolic modifications, which take place without modifying blood glucocorticoid levels, are consistent with the neuroprotective properties of metyrapone as demonstrated in animal models.

Ovarian histomorphometric changes in adult offspring of diabetic rat mothers

In pregnant mothers, maternal diabetes occurs when the pancreas cannot produce enough insulin, which leads to increase blood glucose concentration in the mother and consequently in the foetus, causing various neonatal problems. This study was conducted to evaluate the effects of maternal diabetes on foetal ovarian structure. Sixteen adult female rats were allocated in two equal groups. Diabetes was induced in one group by alloxan. Both groups became pregnant by natural matting. Ninety days after birth, the female offspring were terminated, the body weight and blood glucose of the animals measured and their ovaries removed. Various histological parameters were determined using histological techniques. Results revealed a significant increase in body weight and blood glucose in the offspring of diabetic mothers (ODM) compared to that of controls. The weight, volume and diameter of the ovary and ovarian capsule thickness were decreased in the ODM group. The number and diameter of primary, preantral, antral and preovulatory follicles and corpora lutea were decreased in ovaries in the ODM. Maternal hyperglycaemia exhibited deleterious effects on the reproductive system of their offspring

Comparative effects on glucose absorption of intragastric and post-pyloric nutrient delivery in the critically ill

IntroductionStudies in the critically ill that evaluate intragastric and post-pyloric delivery of nutrient have yielded conflicting data. A limitation of these studies is that the influence in the route of feeding on glucose absorption and glycaemia has not been determined.MethodsIn 68 mechanically ventilated critically ill patients, liquid nutrient (100 ml; 1 kcal/ml containing 3 g of 3-O-Methyl-D-glucopyranose (3-OMG), as a marker of glucose absorption), was infused into either the stomach (n = 24) or small intestine (n = 44) over six minutes. Blood glucose and serum 3-OMG concentrations were measured at regular intervals for 240 minutes and the area under the curves (AUCs) calculated for 'early' (AUC60) and 'overall' (AUC240) time periods. Data are presented as mean (95% confidence intervals).ResultsGlucose absorption was initially more rapid following post-pyloric, when compared with intragastric, feeding (3-OMG AUC60: intragastric 7.3 (4.3, 10.2) vs. post-pyloric 12.5 (10.1, 14.8) mmol/l.min; P = 0.008); however, 'overall' glucose absorption was similar (AUC240: 49.1 (34.8, 63.5) vs. 56.6 (48.9, 64.3) mmol/l.min; P = 0.31). Post-pyloric administration of nutrients was also associated with greater increases in blood glucose concentrations in the 'early' period (AUC60: 472 (425, 519) vs. 534 (501, 569) mmol/l.min; P = 0.03), but 'overall' glycaemia was also similar (AUC240: 1,875 (1,674, 2,075) vs. 1,898 (1,755, 2,041) mmol/l.min; P = 0.85).ConclusionsIn the critically ill, glucose absorption was similar whether nutrient was administered via a gastric or post-pyloric catheter. These data may have implications for the perceived benefit of post-pyloric feeding on nutritional outcomes and warrant further investigation.

Effects of training and nitric oxide on diabetic nephropathy progression in type I diabetic rats

The aim of the paper is to assess nitric oxide (NO) production during aerobic training and its role on the progression of diabetic nephropathy in rats. Induction of diabetes mellitus (DM) was achieved in adult male Wistar rats with streptozotocin. Half of the animals underwent training on a treadmill and the others (sedentary) stayed on a turned-off treadmill for the same period according to the following groups: sedentary control (CTL + SE); training control (CTL + EX); sedentary diabetic (DM + SE); and training diabetic (DM + EX) (n = 9 for all groups). The training on treadmill was carried out at a work rate of 16 m/min, 60 min/d, 5 d/week for eight weeks. Before and after the exercises, rats were placed in individual metabolic cages with standard chow and water ad libitum, for 24-h urine collection, followed by three hours' fasting blood sample withdrawal from the retro-orbital plexus, under anesthesia. Diabetic animals showed reduction of body weight, creatinine and urea depurations and NO excretion, increased blood glucose concentrations, albuminuria and thiobarbituric acid reactive substance (TBARS) excretion, when compared with the respective controls. All these alterations induced by DM were attenuated in the DM + EX versus DM + SE group. Analysis of insulin concentrations at the end of the protocol showed no significant change between the DM + SE and DM + EX groups. In conclusion, our data show that a routine physical exercise resulted in a better control of glycemia with an increased NO bioavailability and oxidative stress control, associated with an amelioration of renal function. We suggest aerobic training and the control of oxidative and nitrosative stress as useful non-pharmacological tools to delay the progression of diabetic nephropathy.

Factors Affecting the Glucose Response to Insulin Injection in Mares: Epinephrine, Short- and Long-Term Prior Feed Intake, Cinnamon Extract, and Omega-3 Fatty Acid Supplementation

Five experiments were conducted with mares to better define factors that might affect the assessment of insulin sensitivity via direct insulin injection, and to then apply this method of assessing insulin sensitivity to trials which tested two potential supplements for improving poor insulin sensitivity in horses. The experiments assessed the effects of the following: (1) previous administration of epinephrine, (2) overnight feed deprivation versus hay or pasture consumption, (3) 10-day acclimatization to hay in a dry lot versus pasture grazing, (4) cinnamon extract supplementation, and (5) fish oil supplementation on insulin sensitivity. Mares of known high and low insulin sensitivities were used in the first three experiments, whereas mares with low insulin sensitivities were used in the supplement trials. Epinephrine administration increased blood glucose concentrations ( P < .05) and prevented the insulin-induced decrease in blood glucose concentrations in both sensitive and insensitive mares. Overnight feed deprivation decreased ( P < .06) insulin sensitivity relative to overnight ad libitum access to hay, and both regimens resulted in reduced insulin sensitivity relative to overnight pasture availability; sensitive and insensitive mares responded similarly except when kept on pasture ( P = .0854). Ten days of hay consumption in a dry lot reduced ( P < .05) insulin sensitivity in insensitive mares, but not in sensitive mares, relative to pasture grazing. Supplementation with cinnamon extract or fish oil had no effect on insulin sensitivity of mares with known low insulin sensitivity under the conditions of these experiments.

Non-diabetic hypoglycaemia: causes and pathophysiology

Hypoglycaemia has many possible causes, although similar symptoms in each case can make diagnosis of the cause complex. Common early warning signs of hypoglycaemia include blurred vision, dizziness, shakiness, sweating, irritability, nausea and palpitations, progressing to confusion, syncope, headache and disturbances of vision. Loss of consciousness and convulsions may follow if corrective steps are not taken to increase blood glucose concentration. In rare cases death may occur if blood glucose remains low for 12 hours or more, as brain function is reduced and cannot be sustained. However, death from hypoglycaemia is avoidable. Causes of non-diabetic hypoglycaemia are an under-reported area in the nursing and wider literature. This article aims to help nursing staff recognise the types and causes of this condition.

Non-diabetic hypoglycaemia: causes and pathophysiology

Hypoglycaemia has many possible causes, although similar symptoms in each case can make diagnosis of the cause complex. Common early warning signs of hypoglycaemia include blurred vision, dizziness, shakiness, sweating, irritability, nausea and palpitations, progressing to confusion, syncope, headache and disturbances of vision. Loss of consciousness and convulsions may follow if corrective steps are not taken to increase blood glucose concentration. In rare cases death may occur if blood glucose remains low for 12 hours or more, as brain function is reduced and cannot be sustained. However, death from hypoglycaemia is avoidable. Causes of non-diabetic hypoglycaemia are an under-reported area in the nursing and wider literature. This article aims to help nursing staff recognise the types and causes of this condition.

Effect of a Pool of Peptides Isolated from Crotalus durissus terrificus (South American Rattlesnake) Venom on Glucose Levels of Mice Fed on a High-Fat Diet

This study investigated the effect of a pool of peptides, isolated from venom of Crotalus durissus terrificus (South American rattlesnake) on glucose concentration in C57BL/6 mice fed on a high-fat diet for 6 weeks. The pool of peptides (molecular mass around of 10 kDa) was obtained using a MidJet apparatus with a cartridge of 10 KDa. The peptide pool was injected intraperitoneally in mice in a single dose (0.5 mg/animal) or multiple doses (0.2 mg/dose). After predetermined times (30, 60, 90 and 120 min) post injections, venous blood samples were collected for enzymatic measurement of serum glucose using a commercial glucose kit (glucose oxidase method). High-fat fed mice showed an increase in blood glucose concentration, in comparison with mice fed on the chow diet. Thirty minutes after a single dose of the peptide pool, high-fat fed animals showed a significant decrease (~47%) in glycemia. However, the glucose level increased again at 60 and 120 min. Conversely, after multiple injections of the pool of peptides administered every 30 min, the blood glucose concentration in the high-fat mice was significantly decreased (~37%) and remained at low levels until 120 min. These results suggest that the tested pool of peptides from Crotalus durissus terrificus contained a peptide (or peptides) with a beneficial role on glucose-lowering action of high-fat fed mice.

Early hyperglycemia following alloxan administration in vivo is not associated with altered hepatic mitochondrial function: acceptable model for type 1 diabetes?

Alloxan and oxidative stress, which have been detected in livers of laboratory animals shortly after in vivo alloxan administration, cause in vitro mitochondrial dysfunction, thus questioning alloxan diabetes as an acceptable model for type 1 diabetes, a model that cannot legitimately be used to investigate mitochondrial metabolism in a diabetic state. In the current study, the blood glucose concentration increased in the drug-treated group of Sprague-Dawley rats (compared with the placebo group) 45 or 60min after alloxan treatment, whereas at 30min the blood glucose concentration was unchanged. State 4, state 3, respiratory control, efficiency of oxidative phosphorylation, and mitochondrial ATP synthase activity, assayed using glutamate plus malate, pyruvate plus malate, or succinate as a substrate, were not negatively altered during the entire study. These results indicated that early increases of blood glucose concentration, after in vivo alloxan administration, did not lead to liver mitochondrial dysfunction, suggesting that alloxan diabetes can be used for the study of liver mitochondrial respiration in a diabetic state.

Comparative evaluation of local anaesthesia with adrenaline and without adrenaline on blood glucose concentration in patients undergoing tooth extractions.

Lignocaine hydrochloride is the most widely used and easily available local anaesthetic agent. Adrenaline is frequently combined with lignocaine to enhance the duration of anaesthesia, decrease toxicity, to achieve vasoconstriction and to provide a bloodless field. This study was conducted to do the comparative evaluation of local anaesthesia with adrenaline and without adrenaline on blood glucose concentration in patients under going tooth extraction. The study was conducted on 120 patients comprising of 60 healthy and 60 diabetic patients. All these patients were in need of multiple extractions. The patients were in the age group of 18-50years. On their first visit the patients were given plain lignocaine and tooth extraction was carried out. One week later the same patient was given lignocaine with 1:80,000 adrenaline to carry out tooth extraction. Serial blood glucose estimations were done at definite intervals (prior to administration of local anaesthetic, immediately after injecting the LA, 10 and 20min following the injection of LA) on both the occasions. The mean blood glucose concentration increased from the base line level of 84.81 to 85.09mg/dl in healthy patients and from 206.82 to 207.09mg/dl in diabetic patients 10min following the injection of 2% plain lignocaine. This increase in blood glucose concentration following the administration of plain lignocaine was statistically not significant (P>0.05). There was statistically significant (P<0.005) increase in the blood glucose concentration from 88.81 to 105.55mg/dl in healthy, and 208.77 to 242.46mg/dl in diabetic patients 20min following the injection of lignocaine with adrenaline. While assessing the generalized effects of local anaesthetic solutions, metabolic as well as haemodynamic responses should be investigated. Adrenaline containing LA should be used with caution in Type 2 diabetics as adrenaline causes suppression of insulin release.

A Recent Update on the Role of Ghrelin in Glucose Homeostasis

Recent evidence highlights an important role of ghrelin in glucose homeostasis. In this review we provide a detailed summary of recent advances in this field. We describe the effects of ghrelin on all aspects of glucose homeostasis including glucose-stimulated insulin secretion, hepatic glucose production and insulin stimulated glucose disposal in the peripheral tissues. The existing evidence suggests ghrelin primarily inhibits insulin release from the pancreas and we highlight an important mechanism involving AMPK-UCP2 ATP-stimulated potassium channels and intracellular calcium regulation. Ghrelin increases hepatic glucose production and prevents glucose disposal in muscle and adipose tissues, which collectively leads to hyperglycemia and impaired glucose tolerance. We discuss the important role ghrelin plays in glucose homeostasis during different metabolic states. During severe calorie restriction, ghrelin increases blood glucose concentrations in order to maintain glucose homeostasis. In diet-induced obesity, ghrelin exacerbates hyperglycemia and promotes a diabetic phenotype.

Abstract 1030: Use of 18F-FDG-PET as a biomarker to demonstrate activity of the novel AKT inhibitor AZD5363 in a xenograft model

Abstract Introduction: The PI3K/Akt/PTEN network is the most frequently de-regulated pathway in human cancer. The protein kinase Akt, a key node on this pathway, has been shown to drive proliferation and survival of tumour cells, and also plays a key role in glucose metabolism. Therefore, it is hypothesized that Akt inhibition can be assessed using 18F-flurodeoxyglucose (18F-FDG) positron emission tomography (PET). The aim of this study was to determine tumour uptake of 18F-FDG 4 hours after an acute dose of AZD5363 or vehicle using a range of doses in the U87-MG xenograft model, the overall goal being to correlate 18F-FDG changes with tumour pharmacodynamics in the absence of any systemic glucose changes. Materials &amp; Methods: AZD5363 was administered orally at 75, 130, 200 and 300mg/kg. Prior to dosing blood glucose concentration was measured and mice were dosed with either vehicle or AZD5363 4 hours prior to imaging. 18F-FDG was administered as an i.v. bolus under anaesthesia; followed by a 45-minute wash-out period and a 20 minute PET scan. Mice were then sacrificed and blood samples taken for pharmacokinetic (PK) analysis and blood glucose concentration. Tumours were removed and snap frozen for pharmacodynamic analysis and background tissues taken for biodistribution analysis. Image analysis was carried out using Inveon Reconstruction Workplace (IRW) software. Biodistribution data were derived from gamma counting. Decay correction and uptake values were calculated using Microsoft Excel and statistical analysis performed using Graph Pad Prism. Results: Mean tumour volumes were not statistically different amongst the five groups. There was significantly decreased 18F-FDG uptake (p&amp;lt;0.05) in the tumour in all of the AZD5363 treated groups as a group average compared to vehicle; maxSUV = 4.06 ± 0.41 (SEM) in the vehicle; 3.42 ± 0.23; 3.16 ± 0.16; 3.12 ± 0.18 and 2.66 ± 0.06 (SEM) in the 75, 130, 200 and 300mg/kg groups respectively. There was a significant increase in blood glucose concentration at only the higher doses of 200 and 300mg/kg compared to the vehicle group post-dose (p&amp;lt; 0.05). There was significantly increased 18F-FDG uptake in the blood, lung and liver from biodistribution data at the 300mg/kg treated dose compared to vehicle (p&amp;lt;0.05). Ex-vivo tumour biomarker analyses demonstrated dose-dependent inhibition of PRAS40, GSK3β and S6 phosphorylation in response to AZD5363. Furthermore, AZD5363 resulted in dose-dependent inhibition of tumour growth in this xenograft model. Conclusions: AZD5363 significantly reduced tumour 18F-FDG uptake at all four doses investigated in U87-MG human glioma xenografts 4 hours after drug administration. This correlated with inhibition of AKT substrate and downstream biomarker phosphorylation in the tumours and was seen at doses that did not cause systemic blood glucose changes. Therefore, 18F-FDG PET has potential as a biomarker for AZD5363 activity in the clinic. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1030. doi:10.1158/1538-7445.AM2011-1030

Impaired Glucose Tolerance in Mice Lacking Cellular Prion Protein

We previously demonstrated that the expression of cellular prion protein (PrPC) in islet [beta]-cells is suppressed in hyperglycemic rats suggesting a major role for PrPC in blood glucose regulation. To further characterize the function of PrPC in glucose homeostasis, we studied glucoregulation in PrPC knockout (PrPC KO) mice. Glucose tolerance, insulin secretion, and insulin sensitivity were analyzed to assess glucoregulation in Zrch I PrPC KO and the C57BL/6 (control) mice. Immunohistochemistry and morphometry were used to measure [beta]-cell mass. Male PrPC KO mice had significantly increased blood glucose concentration 60, 120, and 180 minutes after intraperitoneal injection of glucose compared with C57BL/6 mice. Female PrPC KO mice showed a less pronounced phenotype of glucose intolerance. Evaluation of [beta]-cell mass, insulin and proinsulin deficiency, and insulin resistance in male mice revealed essentially no difference between PrPC KO and control mice. The only exception was an increase in serum insulin concentration in male PrPC KO mice 5 minutes after glucose injection. This report is the first to show that PrPC in [beta]-cells is involved in glucoregulation. A further understanding of the role of PrPC in regulating [beta]-cell function will provide valuable insight into the mechanisms of blood glucose regulation.

Overexpression of Glyoxalase-I Reduces Hyperglycemia-induced Levels of Advanced Glycation End Products and Oxidative Stress in Diabetic Rats

The reactive advanced glycation end product (AGE) precursor methylglyoxal (MGO) and MGO-derived AGEs are associated with diabetic vascular complications and also with an increase in oxidative stress. Glyoxalase-I (GLO-I) transgenic rats were used to explore whether overexpression of this MGO detoxifying enzyme reduces levels of AGEs and oxidative stress in a rat model of diabetes. Rats were made diabetic with streptozotocin, and after 12 weeks, plasma and multiple tissues were isolated for analysis of AGEs, carbonyl stress, and oxidative stress. GLO-I activity was significantly elevated in multiple tissues of all transgenic rats compared with wild-type (WT) littermates. Streptozotocin treatment resulted in a 5-fold increase in blood glucose concentrations irrespective of GLO-I overexpression. Levels of MGO, glyoxal, 3-deoxyglucosone, AGEs, and oxidative stress markers nitrotyrosine, malondialdehyde, and F2-isoprostane were elevated in the diabetic WT rats. In diabetic GLO-I rats, glyoxal and MGO composite scores were significantly decreased by 81%, and plasma AGEs and oxidative stress markers scores were significantly decreased by ∼50%. Hyperglycemia induced a decrease in protein levels of the mitochondrial oxidative phosphorylation complex in the gastrocnemius muscle, which was accompanied by an increase in the lipid peroxidation product 4-hydroxy-2-nonenal, and this was counteracted by GLO-I overexpression. This study shows for the first time in an in vivo model of diabetes that GLO-I overexpression reduces hyperglycemia-induced levels of carbonyl stress, AGEs, and oxidative stress. The reduction of oxidative stress by GLO-I overexpression directly demonstrates the link between glycation and oxidative stress.

Beeinflussung der Blutkonzentration von Glukose und anorganischem Phosphat durch Infusion 5- und 20%iger Glukoselösung bei Milchkühen

The study was performed to evaluate the influence of an intravenous infusion of 5% and 20% dextrose solution on the plasma concentration of glucose and inorganic phosphate in healthy, dairy cows. Ten healthy, lactating, nonpregnant 3 to 6 year-old Holstein-Friesian cows were included in this investigation. The daily milk yield was 20.3±2.7 liters. Blood plasma concentrations of inorganic phosphate and glucose were determined before, during, immediately and 60 minutes after infusion of 0.9% physiological saline, 5% or 20% dextrose solution. A statistically significant influence of dextrose infusion on blood glucose concentration was observed. After 20% dextrose infusion (200 g dextrose) the blood glucose concentration increased by approximately 13.26 mmol/l. The administration of 5% dextrose solution (50 g dextrose) yielded an increase of blood glucose concentration by 3.31 mmol/l. There was no significant correlation between plasma inorganic phosphate concentrations and infusion of 0.9% saline, 5% or 20% dextrose solution. Intravenous administration of 1000 ml of 5% or 20% dextrose solution does not induce a lasting plasma phosphate reduction and is suitable for elevating the blood glucose concentration.

ELEVATION OF PLASMA CORTICOSTERONE TO PHYSIOLOGICALLY RELEVANT LEVELS INCREASED METABOLIC RATE IN A TERRESTRIAL SALAMANDER

Event Abstract Back to Event ELEVATION OF PLASMA CORTICOSTERONE TO PHYSIOLOGICALLY RELEVANT LEVELS INCREASED METABOLIC RATE IN A TERRESTRIAL SALAMANDER Corina Wack1, Sarah DuRant2, William Hopkins2 and Sarah Woodley1* 1 Duquesne University, United States 2 Virginia Tech, Department of Fish and Wildlife Conservation, United States Plasma glucocorticoid hormones (GCs) become elevated when individuals are exposed to stressors. GCs alter intermediary metabolism to increase blood glucose concentrations. In the absence of compensatory mechanisms, this increase in intermediary metabolism may be reflected in whole-animal metabolic rate. Studies in fish, birds, and reptiles have shown that GCs may alter whole animal metabolic rates, but results are conflicting and often involve GCs levels that are not physiologically relevant. A previous study in red-legged salamanders (Plethodon shermani) found that male courtship pheromone increased plasma corticosterone (CORT; primary GC in amphibians) concentrations in males but not females. To understand the possible metabolic effect of elevated plasma CORT, we measured the effects of male courtship pheromone and exogenous application of CORT on oxygen consumption in male red-legged salamanders. Exogenous application of CORT elevated plasma CORT to physiologically relevant levels. Compared to treatment with male courtship pheromone and vehicle, treatment with CORT increased oxygen consumption rates within two hours after treatment resulting in 12% more oxygen consumed over a 2 hr period. Contrary to our previous work, treatment with pheromone did not increase plasma CORT, perhaps because subjects used in this study were not in breeding condition. Our study is one of the few to evaluate the influence of physiologically relevant elevations in CORT on whole animal metabolism in wildlife, and the first to show that elevated plasma CORT increases metabolism in an amphibian. Keywords: stress Conference: ISAREN 2011: 7th International Symposium on Amphibian and Reptilian Endocrinology and Neurobiology, Ann Arbor, United States, 11 Jul - 13 Jul, 2011. Presentation Type: Poster Topic: Stress Citation: Wack C, DuRant S, Hopkins W and Woodley S (2011). ELEVATION OF PLASMA CORTICOSTERONE TO PHYSIOLOGICALLY RELEVANT LEVELS INCREASED METABOLIC RATE IN A TERRESTRIAL SALAMANDER. Front. Endocrinol. Conference Abstract: ISAREN 2011: 7th International Symposium on Amphibian and Reptilian Endocrinology and Neurobiology. doi: 10.3389/conf.fendo.2011.03.00045 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 22 Jul 2011; Published Online: 09 Aug 2011. * Correspondence: Prof. Sarah Woodley, Duquesne University, Pittsburgh, United States, woodleys@duq.edu Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract Supplemental Data The Authors in Frontiers Corina Wack Sarah DuRant William Hopkins Sarah Woodley Google Corina Wack Sarah DuRant William Hopkins Sarah Woodley Google Scholar Corina Wack Sarah DuRant William Hopkins Sarah Woodley PubMed Corina Wack Sarah DuRant William Hopkins Sarah Woodley Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

A needle in a haystack:focus on “Proteomic alterations of distinct mitochondrial subpopulations in the type 1 diabetic heart”

diabetes mellitus is increasingly common throughout the world, due to both an increase in incidence and to decreased mortality of those with diabetes. Unfortunately, diabetes more than doubles the risk of cardiovascular disease in adults, and it even causes its own peculiar form of “diabetic”

Blood volume changes and water appearance in the circulation from water and 3% and 6% carbohydrate drinks

This study investigated water absorption and blood volume changes after drinking water and 3% and 6% carbohydrate drinks. Nine healthy male volunteers completed this crossover study after giving informed consent to participate. On three separate occasions they consumed 500 ml of Evian water (W), a 3% carbohydrate drink (3% CHO) or a 6% carbohydrate drink (6% CHO) to which had been added 10.00±0.01 g of deuterium oxide. Blood samples were collected 10 and 5 min before drink ingestion and at 2, 5, 10, 15, 20, 30, 45 and 60 min after drink ingestion. In addition, subjective feeling questionnaires were completed at intervals throughout and subjects urinated before and after the study period. Blood samples were analysed for haematocrit and haemoglobin, glucose and deuterium concentrations. There was a significant increase in blood glucose concentration after consumption of both the 3% CHO and 6% CHO drinks, with the increase being greater after consumption of the 6% CHO drink. Both the 3% CHO and 6% CHO drinks promoted a significant blood and plasma volume expansion after their consumption whereas there was no change in blood and plasma volumes when water was consumed. Blood deuterium enrichment increased after consumption of all three drinks, but there was no significant difference between drinks. The results suggest that when a significant expansion of blood volume is desired, this can be achieved by consumption of the 3% CHO or 6% CHO drink rather than with plain water consumption. This is likely to be due to the sodium and carbohydrate content of these drinks.

The association between blood glucose and oxidized lipoprotein(a) in healthy young women

BackgroundOxidized lipoproteins play important roles in the atherosclerotic processes. Oxidized lipoprotein(a) (oxLp(a)) may be more potent in atherosclerotic pathophysiology than native Lp(a), a cardiovascular disease-relevant lipoprotein. Increased blood glucose concentrations can induce oxidative modification of lipoproteins. The aim of this study was to investigate the association between circulating oxLp(a) and cardiometabolic variables including blood glucose in healthy volunteers within the normal range of blood glucose.MethodsSeveral cardiometabolic variables and serum oxLp(a) (using an ELISA system) were measured among 70 healthy females (mean age, 22 years).ResultsLp(a) and glucose were significantly and positively correlated with oxLp(a) in simple correlation test. Furthermore, a multiple linear regression analysis showed oxLp(a) to have a weakly, but significantly positive and independent correlation with only blood glucose (β = 0.269, P < 0.05).ConclusionsThese results suggest that increased glucose may enhance the oxidization of Lp(a) even at normal glucose levels.

Physiological responses to temperature and haeme synthesis modifiers in earthworm Lumbricus terrestris (Annelida: Oligochaeta)

Earthworms (Lumbricus terrestris) acclimated at 2° and 6°C above their average habitat temperature (10°C) had respectively 15 and 40% higher rate of respiration than those at habitat temperature. At 14°C, the rate of respiration and blood hemoglobin (Hb) concentration both increased by ∼60 and 50%, respectively, of the values at habitat temperature. At higher temperatures the rate of respiration and Hb synthesis started decreasing. At 20-23°C, the respiration and Hb concentration decreased respectively by about 85% and 35% of that at 14°C. Decrease in blood Hb concentration at higher temperatures appeared to be due to the lowering of the activity of blood enzyme δ-aminolaevulinic acid dehydratase (ALAD). Exposure of 20-23°C-acclimated pale worms to ALAD inhibitor (lead), lowered the already compromised rate of respiration and blood Hb concentration; while exposure to hexachlorobenzene (HCB, inducer of haeme synthesis) and ferric chloride (enhancer of haeme synthesis) did not overcome the inhibitory effect of high temperature on Hb synthesis. At 20-23°C the affinity of Hb for oxygen also decreased as indicated by the lowering of oxy-Hb (HbO) concentration in blood. The lowering of concentration of blood Hb and its affinity for oxygen may lower the amount of oxygen delivered to cells, which may limit the level of aerobic metabolism (glycolysis, oxidative phosphorylation), as indicated by an increase in blood glucose concentration and a decrease in in vitro activities of mitochondrial electron transport system components (ETS) namely NADH-cytochrome c reductase, succinate dehydrogenase, cytochrome c oxidase, and ATPases. Although the oxygen concentration in air, at sea level, does not decrease significantly from 6° to 20-23°C (lack of hypoxia), lowering of both Hb and HbO concentrations by high temperature may cause significant hypoxemia. The latter may lead to inhibition of the activity of muscle mitochondrial respiratory enzymes (ETS). The resulting inhibition of ATP synthesis and hydrolysis may cause deficit of energy needed for peristalsis/fictive locomotion of body and heart muscles (as indicated by a decrease in heart rate) to facilitate diffusion and transport of gases. The upper critical temperature (20-23°C) also slows down the heart rate and causes hyperosmotic stress (hypovolemia). Thus, a rise in soil temperature above 18°C, which inhibits Hb synthesis, Hb oxygenation, and mitochondrial ETS activity, and slows down the heart rate and causes hyperosmotic stress, can make this and higher temperatures lethal to populations of these earthworms, especially in the presence of metabolic inhibitors and respiratory poisons.