scholarly journals Basal blood glucose concentration in free-living striped mice is influenced by food availability, ambient temperature and social tactic

2015 ◽  
Vol 11 (5) ◽  
pp. 20150208 ◽  
Author(s):  
Carsten Schradin ◽  
Neville Pillay ◽  
Anna Kondratyeva ◽  
Chi-Hang Yuen ◽  
Ivana Schoepf ◽  
...  

Vertebrates obtain most of their energy through food, which they store mainly as body fat or glycogen, with glucose being the main energy source circulating in the blood. Basal blood glucose concentration (bBGC) is expected to remain in a narrow homeostatic range. We studied the extent to which bBGC in free-living African striped mice ( Rhabdomys pumilio ) is influenced by ecological factors with a bearing on energy regulation, i.e. food availability, abiotic environmental variation and social tactic. Striped mice typically form extended family groups that huddle together at night, reducing energetic costs of thermoregulation, but solitary individuals also occur in the population. We analysed 2827 blood samples from 1008 individuals of seven different social categories that experienced considerable variation in food supply and abiotic condition. Blood samples were taken from mice in the morning after the overnight fast and before foraging. bBGC increased significantly with food plant abundance and decreased significantly with minimum daily ambient temperature. Solitary striped mice had significantly higher bBGC than group-living striped mice. Our results suggest that adaptive responses of bBGC occur and we found large natural variation, indicating that bBGC spans a far greater homeostatic range than previously thought.

Author(s):  
Li-Nong Ji ◽  
Li-Xin Guo ◽  
Li-Bin Liu

AbstractBlood glucose self-monitoring by individuals with diabetes is essential in controlling blood glucose levels. The International Organization for Standardization (ISO) introduced new standards for blood glucose monitoring systems (BGMS) in 2013 (ISO 15197: 2013). The CONTOUR PLUSThis study evaluated the accuracy and precision of CONTOUR PLUS BGMS in quantitative glucose testing of capillary and venous whole blood samples obtained from 363 patients at three different hospitals.Results of fingertip and venous blood glucose measurements by the CONTOUR PLUS system were compared with laboratory reference values to determine accuracy. Accuracy was 98.1% (96.06%–99.22%) for fingertip blood tests and 98.1% (96.02%–99.21%) for venous blood tests. Precision was evaluated across a wide range of blood glucose values (5.1–17.2 mmol/L), testing three blood samples repeatedly 15 times with the CONTOUR PLUS blood glucose meter using test strips from three lots. All within-lot results met ISO criteria (i.e., SD<0.42 mmol/L for blood glucose concentration <5.55 mmol/L; CV<7.5% for blood glucose concentration ≥5.55 mmol/L). Between-lot variations were 1.5% for low blood glucose concentration, 2.4% for normal and 3.4% for high.Accuracy of both fingertip and venous blood glucose measurements by the CONTOUR PLUS system was >95%, confirming that the system meets ISO 15197: 2013 requirements.


1992 ◽  
Vol 38 (3) ◽  
pp. 411-413 ◽  
Author(s):  
A Y Chan ◽  
C S Ho ◽  
T Y Chan ◽  
R Swaminathan

Abstract We studied the changes in blood glucose concentration in blood samples collected in heparinized specimen tubes containing no other preservative, or containing NaF, D-mannose, or a combination of NaF and D-mannose. Blood concentration in samples taken into NaF decreased by 0.40 mmol/L in the first 2 h; thereafter, there was no change. In samples collected into mannose there was a small but significant decrease in blood glucose concentration with time. When samples containing mannose were analyzed immediately after collection, the concentration of glucose was higher than in later analyses, probably because of an exchange of intracellular glucose for extracellular mannose. When a combination of NaF and mannose was used, the blood glucose concentration was relatively stable but slightly higher than nonpreserved samples for the next 24 h. However, samples containing mannose were unsuitable for electrolyte analysis. We conclude that a combination of D-mannose and NaF may be a better preservative for blood glucose than either compound alone.


Neonatology ◽  
1969 ◽  
Vol 14 (3-4) ◽  
pp. 194-202 ◽  
Author(s):  
P.A.J. Adam ◽  
D. Kornhauser ◽  
D. Link ◽  
R. Schwartz

2014 ◽  
Vol 307 (4) ◽  
pp. H587-H597 ◽  
Author(s):  
Mark W. Sims ◽  
James Winter ◽  
Sean Brennan ◽  
Robert I. Norman ◽  
G. André Ng ◽  
...  

While it is well established that mortality risk after myocardial infarction (MI) increases in proportion to blood glucose concentration at the time of admission, it is unclear whether there is a direct, causal relationship. We investigated potential mechanisms by which increased blood glucose may exert cardiotoxicity. Using a Wistar rat or guinea-pig isolated cardiomyocyte model, we investigated the effects on cardiomyocyte function and electrical stability of alterations in extracellular glucose concentration. Contractile function studies using electric field stimulation (EFS), patch-clamp recording, and Ca2+ imaging were used to determine the effects of increased extracellular glucose concentration on cardiomyocyte function. Increasing glucose from 5 to 20 mM caused prolongation of the action potential and increased both basal Ca2+ and variability of the Ca2+ transient amplitude. Elevated extracellular glucose concentration also attenuated the protection afforded by ischemic preconditioning (IPC), as assessed using a simulated ischemia and reperfusion model. Inhibition of PKCα and β, using Gö6976 or specific inhibitor peptides, attenuated the detrimental effects of glucose and restored the cardioprotected phenotype to IPC cells. Increased glucose concentration did not attenuate the cardioprotective role of PKCε, but rather activation of PKCα and β masked its beneficial effect. Elevated extracellular glucose concentration exerts acute cardiotoxicity mediated via PKCα and β. Inhibition of these PKC isoenzymes abolishes the cardiotoxic effects and restores IPC-mediated cardioprotection. These data support a direct link between hyperglycemia and adverse outcome after MI. Cardiac-specific PKCα and β inhibition may be of clinical benefit in this setting.


2014 ◽  
Vol 19 (3) ◽  
pp. 527-533 ◽  
Author(s):  
Miho Senda ◽  
Susumu Ogawa ◽  
Kazuhiro Nako ◽  
Masashi Okamura ◽  
Takuya Sakamoto ◽  
...  

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