scholarly journals The glucose tolerance test in mice: sex, drugs and protocol.

2021 ◽  
Author(s):  
Matilda Kennard ◽  
Manasi Nandi ◽  
Sarah Chapple ◽  
Aileen King
Keyword(s):  
Blood Glucose ◽  
Glucose Tolerance ◽  
Experimental Approach ◽  
Glucose Tolerance Test ◽  
Drug Effects ◽  
Tolerance Test ◽  
Oral Glucose ◽  
Preclinical Studies ◽  
Glucose Tolerance Tests ◽  
Blood Glucose Concentrations

Background and Purpose: Glucose tolerance tests (GTTs) are commonly used in preclinical studies but are poorly standardised. Male mice are often preferred due to more severe phenotypes which may aid in detecting drug effects. Using novel glucose telemetry in undisturbed mice, the effect of different pre-GTT protocols on blood glucose concentrations, GTTs and detection of drug effects were considered. Experimental Approach: Seven male and female C57Bl/6J mice (8-10 weeks) were implanted with HD-XG glucose telemetry devices. Mice were fasted for 16h overnight or 6h in the daytime following a whole cage change, cage change with retention of used bedding or no cage change prior to i.p.GTTs. Glucose tolerance following oral glucose gavage was compared to voluntary ingestion of gels. Using the most refined procedures, 250mg/kg oral metformin and 10nmol/kg i.p. exendin-4 were tested. Key Results: Blood glucose initially increased following cage changing at the start of the fast. For 6h fasting, retaining bedding reduced these initial responses and produced more timely glucose reductions whereas 16h fasts caused pronounced hypoglycaemia. Impaired glucose tolerance in males was exaggerated following 16h fasting or whole cage changes. Refined procedures including voluntarily ingested glucose gels blunted responses but the effects of exendin-4 and metformin were still observable in both sexes. Conclusion and Implications: Variations in GTT protocol can have profound effects on glucose homeostasis. Improved glucose tolerance due to protocol refinement and/or the use of females still allows for detection of drug effects providing evidence that more severe phenotypes are not required when testing drugs.

GLUCOSE TOLERANCE TESTS MODELING & PATIENT-SIMULATION FOR DIAGNOSIS

2001 ◽  
Vol 01 (02) ◽  
pp. 193-223 ◽  
Author(s):  
SARMA S. DITTAKAVI ◽  
DHANJOO N. GHISTA
Keyword(s):  
Blood Glucose ◽  
Glucose Tolerance ◽  
Oral Glucose Tolerance Test ◽  
Glucose Tolerance Test ◽  
Patient Simulation ◽  
Tolerance Test ◽  
Oral Glucose ◽  
Model Parameters ◽  
Oral Glucose Tolerance ◽  
Glucose Tolerance Tests

Diabetes mellitus is a heterogeneous clinical syndrome characterized by hyperglycemia and long-term specific complications: retinopathy, neuropathy, nephropathy, and cardiomyopathy. Automatic neuropathy leads to visceral denervation producing a variety of clinical abnormalities: cardiac and respiratory dysrythaemias, gastrointestinal motility disorders, urinary bladder dysfunction and impotence. Diabetes mellitus is a leading cause of blindness; renal failure and limb amputation all over the world. The need to detect diabetic risk factors and treat organ disorders and complications associated with diabetes provides the impetus for us to develop the technology for assessment of diabetes, its etiology and severity, as well as for assessing the efficacy of pharmacological therapy. This paper concerns: (i) modelling of blood-glucose regulation and tolerance-testing, (ii) demonstrating patient-simulation of the blood-glucose regulatory models, by means of which the model parameters can be evaluated and related to physiological parameters, and (iii) elucidating how the glucose-regulatory system model's pole-zero representation and the blood glucose-insulin transfer-function can explain the blood glucose response data in intravenous and oral glucose tolerance tests. An easy-to-implement simple clinical-application method is developed to simulate the response of the blood-glucose regulatory model in diabetic patients during intravenous glucose tolerance test and to estimate the model parameters, which can then enable differential diagnosis of diabetes and its severity as well as in early detection of risk-to-diabetes. In the oral glucose-tolerance test, the role of the gut is to facilitate transport of glucose across the intestinal wall. The Michaelis-Menten equation, describing this enzyme-catalyzed reaction rate, can be employed to conclude that the intestinal glucose absorption rate into the blood-compartment from the gut during the oral glucose-tolerance test is constant, almost resembling a rectangular pulse Nevertheless, we have formulated a new rate-control model to simulate the oral glucose-tolerance test data, by means of the response-function of a second-order system of a single-compartment (consisting of the gut and the blood-glucose pool), with the oral glucose-bolus as the impulse-input. We have also demonstrated application of this rate-control model to patients undergoing oral glucose-tolerance test, to evaluate the model parameters. By categorizing the ranges of these parameters for normals and diabetics (varying from mild to severe), we can reliably apply this model and procedure clinically.

scholarly journals Pharmacological potential of methanol extract of Anacardium occidentale stem bark on alloxan-induced diabetic rats

2018 ◽  
Vol 5 (7) ◽  
pp. 2440-2454
Author(s):  
D. A. Omoboyowa ◽  
F. O. Afolabi ◽  
T. C. Aribigbola
Keyword(s):  
Blood Glucose ◽  
Glucose Tolerance ◽  
Glucose Tolerance Test ◽  
Methanol Extract ◽  
Stem Bark ◽  
Tolerance Test ◽  
Diabetic Rats ◽  
Oral Glucose ◽  
Oral Glucose Tolerance ◽  
Β Cells

Background: The anti-hyperglycemic potential of methanol stem bark extract of Anacardium occidentale (MSBEAO) was investigated using an alloxan-induced diabetic rat model. Alloxan administration induces the generation of free radicals which can affect antioxidant status resulting in the disruption of the β-cells of the pancreas. Therefore, this study examines the antioxidant potential of the plant extract and the ameliorating effect on the pancreas of alloxan-induced diabetic rats. Methods: Diabetes was induced by intraperitoneal injection of 150 mg/kg body weight of alloxan monohydrate. MSBEAO, at a concentration of 100 or 200 mg/kg b.w. was orally administered to alloxan-induced diabetic rats and normal rats. The hypoglycemic effect, oral glucose tolerance test, and biochemical assay of alloxan-induced diabetic rats were assayed using standard procedures. Results: Preliminary phytochemical screening of the extract revealed the presence of alkaloids, tannins, saponins, terpenoids, carbohydrates, and phenols at moderate concentrations. The lethality dose (LD50) of the plant extract was found to be equal to or less than 5000 mg/kg b.w. The hypoglycemic effect of the extract on the non-diabetic rats revealed a significant (p<0.05) decrease in the blood glucose concentration of animals administered with 1 g/kg b.w. of the extract, compared to normal control rats administered with normal saline. In the oral glucose tolerance test, the methanol extract exerted the highest response, similar to glibenclamide after 15 and 30 minutes of administration, compared to the control rats. The methanol extract yielded the highest blood glucose lowering effects after 9 days of treatment (p<0.05), compared to diabetic rats administered with normal saline and 0.3 mg/kg b.w. of glibenclamide. Administration of the extract at 200 mg/kg b.w. showed improved pancreas architecture and regeneration of the β-cells, compared with the pancreas of animals in the other groups. Conclusion: The results of this study suggest that MSBEAO is a potentially effective agent for the management of diabetes which might result from the antioxidant-generating capacity of the stem bark.

scholarly journals GESTATIONAL DIABETES MELLITUS

2012 ◽  
Vol 19 (04) ◽  
pp. 462-468
Author(s):  
M. IKRAM ◽  
SYED HAIDER HASAN ALAM ◽  
SHAFQAT MUKHTAR ◽  
M. Saeed
Keyword(s):  
Diabetes Mellitus ◽  
Blood Glucose ◽  
Gestational Diabetes ◽  
Glucose Tolerance ◽  
Gestational Diabetes Mellitus ◽  
Glucose Tolerance Test ◽  
Fasting Blood Glucose ◽  
Tolerance Test ◽  
Oral Glucose ◽  
Oral Glucose Tolerance

Introduction: Gestational diabetes mellitus is common disorder in pregnancy. It is associated with adverse pregnancy outcome. There is no consensus regarding the optimal approach to screening of gestational diabetes mellitus. The present study has tried toobserve the value of fasting blood glucose in screening of gestational diabetes. Objective: To determine the frequency of patients in whomfasting blood glucose and 100gm glucose tolerance show agreement for screening of gestational diabetes mellitus at 24 -28 wks. Studydesign: Comparative cross sectional study. Settings: The study was conducted at Gynecology and Obstetrics department Shaikh ZayedFederal Post Graduate Institute Lahore. Duration of study with dates: 6 months from 12Nov 2010 to 11 May 2011. Material and method: Thestudy included 135 booked patients with positive family history of diabetes mellitus. All patients underwent fasting blood glucose at 24-28 weeksof gestation, regardless of results of fasting blood glucose on next visit they underwent 100g oral glucose tolerance test (OGTT). The agreementbetween fasting blood glucose and 100g oral glucose tolerance test was calculated in frequency and percentages. Results: The mean age ofwomen in studied population was 27.15±3.70.Out of 135 patients 86.7 %( 117) showed agreement between results of fasting blood glucose and100g OGTT while 13.31 %( 18) showed no agreement between both of the tests. Conclusions: Fasting blood glucose is a good screeningoption for gestational diabetes mellitus along with positive history. It provides a simple, cheap and more practical test for screening of gestationaldiabetes mellitus. However diagnostic confirmation with 100g OGTT should be done.

scholarly journals Preliminary phytochemical screening and evaluation of hypoglycemic properties of the root extract of Uveria chamae

2015 ◽  
Vol 10 (2) ◽  
pp. 326 ◽  
Author(s):  
Emordi Jonathan Emeka ◽  
Agbaje Esther Oluwatoyin ◽  
Oreagba Ibrahim Adekunle ◽  
Iribhogbe Osede Ignis
Keyword(s):  
Single Dose ◽  
Blood Glucose ◽  
Glucose Tolerance ◽  
Glucose Tolerance Test ◽  
Tolerance Test ◽  
Oral Glucose ◽  
Oral Glucose Tolerance ◽  
Phytochemical Screening ◽  
Glucose Levels ◽  
Blood Glucose Levels

<p>The purpose of this study is to evaluate the hypoglycaemic properties and preliminary phytochemical screening of <em>Uveria chamae</em>. The hypoglycaemic properties of <em>Uveria chamae</em> was assessed on normoglycaemic rat that received single dose of the extract at 250 and 500 mg/kg body weight and blood glucose levels estimated at 2, 4, and 6 hours (single dose study). The hypoglycaemic property of the extract was also evaluated in normoglycemic rats by oral glucose tolerance test. Phytochemical screening of the extract for the presence of secondary metabolites was performed with standard methods. The extract showed a significant (p&lt;0.05) reduction in blood glucose levels at 2h and 6h compared to control.  The oral glucose tolerance test  result also showed a significant decrease (p&lt;0.05) in blood glucose levels . The study showed that the extract, <em>Uveria chamae</em> has hypoglycaemic properties which may be accounted for by the presence of the phytochemicals.</p><p> </p>

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