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

2018 ◽  
Vol 1 (4) ◽  
Author(s):  
Shiyi He ◽  
Ying Zhang

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.

1988 ◽  
Vol 254 (2) ◽  
pp. E137-E143 ◽  
Author(s):  
S. Hulman ◽  
R. Kliegman ◽  
J. Heng ◽  
E. Crouser

Glucose turnover, clearance and response to insulin were determined in fasted newborn and adult dogs. Fasting levels of glucose and insulin and rates of glucose turnover and clearance were not different between the two groups. Blood glucose correlated with basal glucose turnover in newborn pups but not in adult dogs. Glucose turnover was not related to fasting plasma insulin levels. Glucose clearance was an inverse function of blood glucose levels among newborn but not adult dogs. Glucose clearance and blood glucose levels were not related to insulin concentrations. In response to euglycemic hyperinsulinemia, glucose metabolism increased 4-fold among adults but only 1.7-fold in pups. Hyperglycemic hyperinsulinemia increased glucose metabolism in both groups but to a much greater extent in the pups. Euglycemic hyperinsulinemia increased the metabolic clearance rate of glucose 4.2-fold among adults but only 1.8-fold in newborn dogs. In response to hyperglycemic hyperinsulinemia glucose clearance rates were now similar. Despite euglycemic hyperinsulinemia, the newborn dog had an attenuated response to insulin, demonstrating lower rates of glucose metabolism and glucose clearance. The response to the hyperglycemic stimuli suggests that maximal glucose uptake was not achieved during hyperinsulinemia alone. This response supports the concept of glucose-mediated regulation of glucose disposal in newborn animals.


2021 ◽  
pp. 1-8
Author(s):  
Jae-Hun Lee ◽  
Sang Hee Ji ◽  
Jae Yun Jung ◽  
Min Young Lee ◽  
Chi-Kyou Lee

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.


2007 ◽  
Vol 34 (6) ◽  
pp. 916-925 ◽  
Author(s):  
M. L. Soto-Montenegro ◽  
J. J. Vaquero ◽  
C. Arango ◽  
G. Ricaurte ◽  
P. García-Barreno ◽  
...  

1988 ◽  
Vol 60 (3) ◽  
pp. 499-507 ◽  
Author(s):  
Susan Southon ◽  
Z. Kechrid ◽  
A. J. A. Wright ◽  
Susan J. Fairweather-Tait

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.


2021 ◽  
Author(s):  
xishuai Wang ◽  
zhiqing Wang ◽  
donghui Tang

Abstract Purpose: In the present study, we attempted to investigate whether aerobic exercise (AE) could prevent sepsis and its complications and explored the related mechanisms. Methods: Forty ICR mice were divided into four groups: Control (Con), Lipopolysaccharide (LPS), Exercise (Ex), and Exercise + LPS (Ex + LPS) groups. Ex and Ex + LPS mice were performed with low-intensity AE for 4 weeks. LPS and Ex + LPS mice received 5 mg/kg LPS intraperitoneally for induction of sepsis. Histopathological micrographs showed the organ injury. This study examined the effects of AE on LPS-induced changes in systemic inflammation, pulmonary inflammation, lung permeability, oxidative stress-related indicators in the lung, blood glucose levels, plasma lactate levels, and plasma high-mobility group box 1 (HMGB1) levels, and bronchoalveolar lavage fluid (BALF) cell count. Sixty mice were used to perform survival rate analysis. Results: AE improved survival rates, MODS, and aortic injury in mice with sepsis. AE decreased LPS-induced oxidative stress injury in lung tissue. AE reduced the infiltration of neutrophils in the lung, liver, kidney, and heart tissues. AE suppressed CXCL-1, CXCL-8, IL-6, and TNF-α mRNA expression but activated IL-1RN, IL-10, Sirt-1, and Nrf-2 mRNA expression in the lung. AE decreased the serum levels of lactate and HMGB1 but increased blood glucose levels during sepsis. Conclusions: AE improves sepsis-associated lung, liver, kidney, heart, and aortic injury and death. AE modulates the inflammatory-anti-inflammatory and oxidative-antioxidative balance in the lung. AE, which can regulate the Warburg effect and impair LPS-induced lactate and HMGB1 release, is a novel therapeutic strategy for sepsis targeting aerobic glycolysis.


2014 ◽  
Vol 11 (1) ◽  
pp. 24-31
Author(s):  
I I Dedov ◽  
G A Melnichenko ◽  
E A Troshina ◽  
N V Mazurina ◽  
N A Ogneva ◽  
...  

We’ve studied a carbohydrate metabolism in morbidly obese (MO) patients and the patients after bariatric surgery. The patients of the 1st group had BMI40 (n=22) and no history of diabetes mellitus. Patients after biliopancreatic diversion (BPD) performed for MO were included in the 2nd group (n=23). The 3rd group was a control group of normal weight healthy subjects (n=22). Blood glucose levels, insulin, GLP-1, GIP and glucagon during the OGTT (with 75 g of glucose) at 0, 30, 60 and 120 minutes were measured in all patients. In MO group fasting glucose levels were the highest. Impaired glucose metabolism was revealed in 68.2% of patients (n=10). Impaired fasting glucose (IFG) was diagnosed in 4 cases (18.2%), impaired glucose tolerance (IGT) in 11 patients (50%). In the BPD postprandial blood glucose levels (120 min) were lower if compared to the other groups. In 4 individuals (17.4%) we found postprandial hypoglycemia (2.8 mmol/l). Patients of the MO group had the highest fasting insulin levels and HOMA-IR (p0.001). The maximum of insulin concentration was seen on minute 30 of the OGTT in the 2nd and 3rd groups, and it was significantly higher in the post-bariatric patients (p=0.026). In MO group the maximum of the plasma insulin levels were on the 60th minute and were still elevated after 120 minutes. Fasting and stimulated (on the 30th minute) levels of GLP-1 were significantly higher after BPD (р=0.037 and p=0.022 at 0 and 30 min, respectively). Morbidly obese patients had higher fasting and stimulated GIP. Fasting glucagon concentrations were similar in the surgical and control groups, while the people with MO had higher initial levels of glucagon (p=0.013) and it was not suppressed during the OGTT (p=0.076). Glucose intolerance and insulin resistance incidence was higher in MO patients. Hyperglucagonemia, increased GIP and decreased GLP-1 levels are observed in MO patients. Stimulated plasma insulin and GLP-1 concentrations were significantly increased in patients who underwent BPD, and may cause postprandial hypoglycemia.


Endocrinology ◽  
2018 ◽  
Vol 160 (1) ◽  
pp. 193-204 ◽  
Author(s):  
Isadora C Furigo ◽  
Miriam F Suzuki ◽  
João E Oliveira ◽  
Angela M Ramos-Lobo ◽  
Pryscila D S Teixeira ◽  
...  

Abstract Previous studies have shown that bromocriptine mesylate (Bromo) lowers blood glucose levels in adults with type 2 diabetes mellitus; however, the mechanism of action of the antidiabetic effects of Bromo is unclear. As a dopamine receptor agonist, Bromo can alter brain dopamine activity affecting glucose control, but it also suppresses prolactin (Prl) secretion, and Prl levels modulate glucose homeostasis. Thus, the objective of the current study was to investigate whether Bromo improves insulin sensitivity via inhibition of Prl secretion. Male and female ob/ob animals (a mouse model of obesity and insulin resistance) were treated with Bromo and/or Prl. Bromo-treated ob/ob mice exhibited lower serum Prl concentration, improved glucose and insulin tolerance, and increased insulin sensitivity in the liver and skeletal muscle compared with vehicle-treated mice. Prl replacement in Bromo-treated mice normalized serum Prl concentration without inducing hyperprolactinemia. Importantly, Prl replacement partially reversed the improvements in glucose homeostasis caused by Bromo treatment. The effects of the Prl receptor antagonist G129R-hPrl on glucose homeostasis were also investigated. We found that central G129R-hPrl infusion increased insulin tolerance of male ob/ob mice. In summary, our findings indicate that part of Bromo effects on glucose homeostasis are associated with decrease in serum Prl levels. Because G129R-hPrl treatment also improved the insulin sensitivity of ob/ob mice, pharmacological compounds that inhibit Prl signaling may represent a promising therapeutic approach to control blood glucose levels in individuals with insulin resistance.


1992 ◽  
Vol 72 (1) ◽  
pp. 361-365 ◽  
Author(s):  
F. Trabelsi ◽  
S. Cardin ◽  
R. Helie ◽  
G. R. Brisson ◽  
J. M. Lavoie

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)


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