Combined effect of 2-deoxy-D-glucose and exercise on plasma catecholamine response

2-Deoxy-D-glucose (2-DG) is a nonmetabolizable analogue of glucose that, by competitive inhibition of glucose utilization, produces a central neuroglucopenia and a peripheral hyperglycemia. This glucopenic agent was used to gain more insight into the combined effects of central glucopenia and exercise on plasma catecholamine response. This was carried out by comparing one group of exercising (26 m/min, 0% grade) rats injected with 2-DG (2-DG-EX; 250 mg/kg iv) with two control groups: one group of exercising rats injected with a saline solution (SAL-EX) and one group of resting rats injected with 2-DG (2-DG-RE). Significant (P less than 0.05) increases in blood glucose levels were observed 10 min after administration of 2-DG (7.2–13.8 and 7.3–12.4 mmol/l in 2-DG-EX and 2-DG-RE groups, respectively). These elevated blood glucose levels were maintained throughout the experiment in the 2-DG-RE condition but decreased in 2-DG-EX rats to levels observed in the SAL-EX group after 45 min of running (13.8–8.0 mmol/l). The combination of 2-DG-induced neuroglucopenia and exercise resulted in an additive response of norepinephrine (0.59 vs. 0.34 and 0.34 ng/ml; t = 12 min) and an amplified epinephrine response (1.4 vs. 0.37 and 0.31 ng/ml; t = 12 min) compared with the responses to each stimulus alone (2-DG-EX vs. 2-DG-RE and SAL-EX, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Download Full-text

High Blood Glucose Levels Affect Auditory Brainstem Responses after Acoustic Overexposure in Rats

Audiology and Neurotology ◽

10.1159/000511448 ◽

2021 ◽

pp. 1-8

Author(s):

Jae-Hun Lee ◽

Sang Hee Ji ◽

Jae Yun Jung ◽

Min Young Lee ◽

Chi-Kyou Lee

Keyword(s):

Blood Glucose ◽

Hearing Threshold ◽

Auditory Brainstem ◽

Diabetic Rats ◽

Control Groups ◽

High Blood Glucose ◽

Glucose Levels ◽

Blood Glucose Levels ◽

Hearing Function ◽

Brainstem Response

Introduction: Diabetes mellitus (DM) is a systemic disease characterized by hyperglycemia and several pathological changes. DM-related hearing dysfunctions are associated with histological changes. Here, we explore hearing function and synaptic changes in the inner hair cells (IHCs) of rats with streptozotocin (STZ)-induced diabetes. Methods: STZ was injected to trigger diabetes. Rats with DM were exposed to narrow-band noise (105 dB SPL) for 2 h, and hearing function was analyzed 1, 3, 7, and 14 days later. Both the hearing threshold and the peak 1 amplitude of the tone auditory brainstem response were assessed. After the last functional test, animals were sacrificed for histological evaluation. Results: We found no changes in the baseline hearing threshold; however, the peak 1 amplitude at the low frequency (4 kHz) was significantly higher in both DM groups than in the control groups. The hearing threshold had not fully recovered at 14 days after diabetic rats were exposed to noise. The peak 1 amplitude at the higher frequencies (16 and 32 kHz) was significantly larger in both DM groups than in the control groups. The histological analysis revealed that the long-term DM group had significantly more synapses in the 16 kHz region than the other groups. Conclusions: We found that high blood glucose levels increased peak 1 amplitudes without changing the hearing threshold. Diabetic rats were less resilient in threshold changes and were less vulnerable to peak 1 amplitude and synaptic damage than control animals.

Download Full-text

Effect of reduced dietary zinc intake on carbohydrate and Zn metabolism in the genetically diabetic mouse (C57BL/KsJ db+/db+)

British Journal Of Nutrition ◽

10.1079/bjn19880122 ◽

1988 ◽

Vol 60 (3) ◽

pp. 499-507 ◽

Cited By ~ 9

Author(s):

Susan Southon ◽

Z. Kechrid ◽

A. J. A. Wright ◽

Susan J. Fairweather-Tait

Keyword(s):

Blood Glucose ◽

Control Diet ◽

Fasting Blood Glucose ◽

Liver Glycogen ◽

Diabetic Mouse ◽

Whole Body ◽

Diabetic Mice ◽

Control Groups ◽

Glucose Levels ◽

Blood Glucose Levels

1. Male, 4–5-week-old, genetically diabetic mice (C57BL/KsJ db/db) and non-diabetic heterozygote litter-mates (C57BL/KsJ db/+)were fed on a diet containing 1 mg zinc/kg (low-Zn groups) or 54 mg Zn/kg (control groups) for 27 d. Food intakes and body-weight gain were recorded regularly. On day 28, after an overnight fast, animals were killed and blood glucose and insulin concentrations, liver glycogen, and femur and pancreatic Zn concentrations were determined.2. The consumption of the low-Zn diet had only a minimal effect on the Zn status of the mice as indicated by growth rate, food intake and femur and pancreatic Zn concentrations. In fact, diabetic mice fed on the low-Zn diet had a higher total food intake than those fed on the control diet. The low-Zn diabetic mice had higher fasting blood glucose and liver glycogen levels than their control counterparts. Fasting blood insulin concentration was unaffected by dietary regimen.3. A second experiment was performed in which the rate of loss of 65Zn, injected subcutaneously, was measured by whole-body counting in the two mouse genotypes over a 28 d period, from 4 to 5 weeks of age. The influence of feeding low-Zn or control diets was also examined. At the end of the study femur and pancreatic Zn and non-fasting blood glucose levels were determined.4. All mice fed on the low-Zn diet showed a marked reduction in whole-body 65Zn loss compared with those animals fed on the control diet. In the low-Zn groups, the loss of 65Zn from the diabetic mice was significantly greater than that from heterozygote mice. This difference was not observed in the control groups. Blood glucose levels were elevated in the low-Zn groups. Possible reasons for these observations are discussed.5. The present study demonstrates an adverse effect of reduced dietary Zn intake on glucose utilization in the genetically diabetic mouse, which occurred before any significant tissue Zn depletion became apparent.

Download Full-text

Evidence that increased glucose cycling in islets of diabetic ob/ob mice is a primary feature of the disease

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.1995.269.4.e623 ◽

1995 ◽

Vol 269 (4) ◽

pp. E623-E626 ◽

Cited By ~ 1

Author(s):

A. Khan ◽

S. Efendic

Keyword(s):

Blood Glucose ◽

Dimethyl Sulfoxide ◽

Insulin Release ◽

Glucose Oxidation ◽

Glucose Utilization ◽

Glucose Levels ◽

Blood Glucose Levels ◽

Blood Glucose Concentrations ◽

Old Mice ◽

Diabetic Syndrome

Glucose cycling (GC) is increased in pancreatic islets from hyperglycemic 6-mo-old ob/ob mice. We determined whether normalization of glycemia alters islet GC and insulin release in response to glucose as well as oxidation and utilization of the glucose. Mice were treated with phlorizin in dimethyl sulfoxide (DMSO) for 10 days, which resulted in normalization of blood glucose concentrations. Controls received DMSO. The mice were fasted overnight and killed, and their islets were isolated for measurements of insulin release at 5.5 and 16.7 mM glucose and at 16.7 mM glucose plus 10 mM arginine. GC was measured by the incorporation of 3H from 3H2O into carbon 2 of glucose, glucose oxidation by the yield of 14CO2 from [U-14C]glucose, and glucose utilization by the yield of 3H2O from [5-3H]glucose. Phlorizin treatment did not alter the response of insulin to glucose and to glucose plus arginine. GC was 30% in control and phlorizin-treated animals. Glucose oxidation and utilization were also the same in both groups. In fed 10- to 12-mo-old mice exhibiting a broad range of blood glucose levels, there was no correlation between GC and either insulin release or glucose concentrations. Thus the islets of ob/ob mice exhibit an increased rate of GC regardless of glycemia. This indicates that the increased rate of GC is an important characteristic of the diabetic syndrome in these animals and not simply secondary to hyperglycemia.

Download Full-text

Blood glucose replacement rates in normal and diabetic humans

Journal of Applied Physiology ◽

10.1152/jappl.1961.16.5.789 ◽

1961 ◽

Vol 16 (5) ◽

pp. 789-795 ◽

Cited By ~ 24

Author(s):

George A. Reichard ◽

A. Gerson Jacobs ◽

Philip Kimbel ◽

Norman J. Hochella ◽

Sidney Weinhouse

Keyword(s):

Blood Glucose ◽

Intravenous Injection ◽

Glucose Utilization ◽

Specific Activity ◽

Normal Subjects ◽

Utilization Rate ◽

Replacement Rate ◽

Glucose Levels ◽

Glucose Carbon ◽

Blood Glucose Levels

The rate of decrease in specific activity of blood glucose following intravenous injection of uniformly C14–labeled glucose in a series of 13 nondiabetic and 19 diabetic humans was measured over periods of 3—6 hr. In the nondiabetic humans the specific activity decreased exponentially for about 3 hr, then usually slowed down gradually over the next 3 hr. From the curves obtained up to 3 hr, rates of blood glucose replacement were estimated to be 120 mg/kg/hr, with a range of from 84 to 153 mg/kg/hr. The high and fluctuating blood glucose levels of the diabetic subjects made estimations of replacement rate somewhat uncertain, but despite a wider spread of values, the average, at 109 mg/kg/hr, was not markedly different from that of the nondiabetic subjects. Mild diabetics on the whole had a lower replacement rate, whereas severe diabetics had a markedly higher replacement rate than the normal subjects. The proportion of blood glucose carbon appearing in the respiratory CO2 was also similar—in nondiabetics, 25±3%, and in diabetics, 22 ± 5%. Despite the higher glucose pool in the diabetics, the glucose spaces were about the same at 30 ± 5% and 29 ± 3%, respectively. Taking into consideration a glucose utilization rate by brain of 60—70 mg/kg/hr, the turnover data indicate that relatively little of the glucose which enters the blood in the fasting human is used by the peripheral musculature. Submitted on November 25, 1960

Download Full-text

Renal gluconeogenesis and increased glucose utilization in shock

American Journal of Physiology-Legacy Content ◽

10.1152/ajplegacy.1976.231.3.872 ◽

1976 ◽

Vol 231 (3) ◽

pp. 872-879 ◽

Cited By ~ 9

Author(s):

LT Archer ◽

B Benjamin ◽

MM Lane ◽

LB Hinshaw

Keyword(s):

Blood Glucose ◽

Glucose Utilization ◽

Endotoxic Shock ◽

Endotoxin Shock ◽

In Vitro Experiments ◽

Blood Components ◽

Glucose Levels ◽

Blood Glucose Levels ◽

Renal Gluconeogenesis

The roles of renal gluconeogenesis and glucose utilization in control, hemorrhaged, and endotoxin-injected animals were investigated using anesthetized, eviscerated, nonnephrectomized and nephrectomized dogs. Results demonstrate an increased glucose utilization in both hemorrhagic and endotoxic shock which was marked after endotoxin. Since blood glucose values dropped more in nephrectomized, hemorrhaged animals, in contrast to the nonnephrectomized, hemorrhaged dogs, the kidneys were assumed to perform a significant gluconeogenic role. The kidneys did not appear to perform gluconeogenesis in endotoxin shock since blood glucose levels were comparable in eviscerated, endotoxin-treated animals whether nephrectomized or not. To ascertain the tissue responsible for the increased glucose utilization in endotoxin shock, a study was performed with endotoxin added to blood in vitro (estimated LD100 concentration). The endotoxin-treated blood (n = 7) demonstrated an increased glucose utilization compared with saline controls (n = 7) (P less than or equal 0.02). Acclerated glucose utilization rates were comparable between the eviscerated, nephrectomized animals and in vitro experiments. These data suggest that excessive glucose demand by certain blood components may partially explain the lethal hypoglycemia of endotoxin shock.

Download Full-text

SIRT1 Activation by Equisetum arvense L. (Horsetail) Modulates Insulin Sensitivity in Streptozotocin Induced Diabetic Rats

Molecules ◽

10.3390/molecules25112541 ◽

2020 ◽

Vol 25 (11) ◽

pp. 2541

Author(s):

Csaba Hegedűs ◽

Mariana Muresan ◽

Andrea Badale ◽

Mariann Bombicz ◽

Balázs Varga ◽

...

Keyword(s):

Blood Glucose ◽

Insulin Sensitivity ◽

Diabetic Rats ◽

Signal Pathways ◽

Equisetum Arvense ◽

Control Groups ◽

Glucose Levels ◽

Blood Glucose Levels ◽

Inflammatory Processes ◽

Cardioprotective Effects

BACKGROUND: Equisetum arvense L., commonly known as field horsetail is a perennial fern of which extracts are rich sources of phenolic compounds, flavonoids, and phenolic acids. Activation of SIRT1 that was shown to be involved in well-known signal pathways of diabetic cardiomyopathy has a protective effect against oxidative stress, inflammatory processes, and apoptosis that are the basis of diseases such as obesity, diabetes mellitus, or cardiovascular diseases. The aim of our study was to evaluate the antidiabetic and cardioprotective effects of horsetail extract in streptozotocin induced diabetic rats. METHODS: Diabetes was induced by a single intraperitoneal injection of 45 mg/kg streptozotocin. In the control groups (healthy and diabetic), rats were administered with vehicle, whilst in the treated groups, animals were administered with 50, 100, or 200 mg/kg horsetail extract, respectively, for six weeks. Blood glucose levels, glucose tolerance, and insulin sensitivity were determined, and SIRT1 levels were measured from the cardiac muscle. RESULTS: The horsetail extract showed moderate beneficial changes in blood glucose levels and exhibited a tendency to elevate SIRT1 levels in cardiomyocytes, furthermore a 100 mg/kg dose also improved insulin sensitivity. CONCLUSIONS: Altogether our results suggest that horsetail extract might have potential in ameliorating manifested cardiomyopathy acting on SIRT1.

Download Full-text

PO-146 Effects of aerobic exercise training on GTT and ITT in apelin Knockout mice

Exercise Biochemistry Review ◽

10.14428/ebr.v1i4.10493 ◽

2018 ◽

Vol 1 (4) ◽

Author(s):

Shiyi He ◽

Ying Zhang

Keyword(s):

Blood Glucose ◽

Glucose Metabolism ◽

Exercise Training ◽

Aerobic Exercise ◽

Aerobic Exercise Training ◽

Control Groups ◽

Glucose Levels ◽

Blood Glucose Levels ◽

Insulin Tolerance ◽

Glucose Clearance

Objective Aerobic exercise training is important to prevent and cure chronic diseases such as diabetes, cardiovascular diseases and so on. Apelin has been identified as a novel myokine in recent years, and the exogenous supplementation of apelin can promote the glucose absorption, the biosynthesis of mitochondria and the oxidation of fatty acids in skeletal muscle. Intraperitoneal glucose (GTT) and insulin tolerance tests (ITT) are useful in vivo assays that provide approximations of glucose metabolism and homeostasis. The bigger area under the curve (AUC) confirmed the decreased glucose clearance, which is evaluated by GTT. However, the mechanism of apelin mediating glucose metabolism during aerobic exercise training is not clear. Our study was to investigate the differences of GTT and ITT after four weeks training between wild-type (WT) mice (C57BL/6J) and apelin Knockout (KO) mice. Methods Two-month-old WT and KO were divided into trained and control groups (n=8-10/group) respectively. There are four groups: WT control (WC), apelin KO control (KC), WT trained (WT), and apelin KO trained (KT). The trained groups were trained on treadmills for four weeks (six days per week and one hour per day). In order to maintain the exercise intensity, the speed is at 70%-75% VO2max with an incline of 5 degrees. The control groups were kept at a sedentary condition. after four weeks of interventions, glucose was measured at 0, 15, 30, 45, 60, 90, 120min following GTT. Glucose was also measured at 0, 30, 60, 90, 120min following ITT. Results (1) blood glucose levels and AUC of the KC were significantly bigger than those of WC. ITT showed that KC also had slower insulin-stimulated glucose clearance compared with the WC. (2) Following 4-week training, KT had lower blood glucose levels and AUC of the KT was significantly smaller than those of KC. KT had faster insulin-stimulated glucose clearance compared with KC. Conclusions Without apelin, glucose tolerance and insulin tolerance in mice will decrease. And aerobic exercise training improves them in apelin deficiency mice.

Download Full-text