Preabsorptive insulin release and hypoglycemia in rats

1976 ◽  
Vol 230 (1) ◽  
pp. 56-60 ◽  
Author(s):  
J Louis-Sylvestre
Keyword(s):  
Blood Glucose ◽  
Insulin Release ◽  
Oral Intake ◽  
Hypothalamic Nucleus ◽  
Oral Glucose ◽  
Glucose Load ◽  
Glucose Intake ◽  
Metabolic Conditions ◽  
Freely Moving ◽  
Two Peaks

Peripheral blood glucose and immunologically reactive insulin levels were determined in freely moving normal rats which were submitted either to a free oral glucose load or to a gastric administration of the glucose load. Identical determinations were performed in ventromedial hypothalamic nucleus-(VMH) lesioned and vagotomized rats after the same oral intake. It was demonstrated that: 1) a free oral glucose intake was immediately followed by two peaks of insulun release and a resultant decrease in blood glucose; 2) a gastric glucose load resulted in a single peak of insulin release and the concomitant decline in blood glucose; 3) the recorded blood glucose level was the resultant of the insulin-induced hypoglycemia and the postabsorptive hyperglycemia; and 4) the responses were largely exaggerated in VMH-lesioned rats and abolished by vagotomy. It is concluded that the early prandial insulin release reflexly induced by food-related stimuli temporarily enhances the metabolic conditions which provoke feeding.

Effect of hand heating by a warm air box on O2 consumption of the contralateral arm

1992 ◽  
Vol 72 (6) ◽  
pp. 2364-2368 ◽  
Author(s):  
E. E. Blaak ◽  
M. A. Van Baak ◽  
K. P. Kempen ◽  
W. H. Saris
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Oxygen Consumption ◽  
Skin Temperature ◽  
Forearm Blood Flow ◽  
Venous Blood ◽  
Oral Glucose ◽  
Glucose Load ◽  
Glucose Intake ◽  
Integrated Response

Arterialization of venous blood is often used in studying forearm metabolism. Astrup et al. [Am. J. Physiol. 255 (Endocrinol. Metab. 18): E572-E578, 1988] showed that heating of the hand by a warming blanket caused a redistribution of blood flow in the contralateral arm and thus introduced errors in forearm skeletal muscle flux calculations. The present study was undertaken to investigate how hand heating by a warm air box (60 degrees C) would affect metabolism and blood flow in the contralateral arm before and during 3 h after a glucose load. Eleven healthy volunteers (5 males, 6 females) underwent an oral glucose tolerance test (70 g) on two different occasions, one test with and one without heating of the contralateral hand, in random order. Heating the hand for 30 min before glucose intake did not affect skin temperature, rectal temperature, deep venous oxygen saturation, forearm blood flow, or oxygen consumption of forearm skeletal muscle. Although, after the glucose load, heating significantly increased forearm blood flow (P less than 0.05), the integrated response after glucose was not significantly different between control and heating experiments [67 +/- 43 and 117 +/- 41 (SE) ml/100 ml tissue]. With both conditions, there was an increase in skin temperature (P less than 0.001, integrated response control: 369 +/- 79 and heating: 416 +/- 203 degrees C) and oxygen consumption of forearm muscle (control: 290 +/- 73, P less than 0.05 and heating: 390 +/- 130 mumol/100 ml, P less than 0.05) after glucose intake. These responses did not significantly differ between the conditions.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Evaluation of role of concentration and molecular weight of oat β-glucan in determining effect of viscosity on plasma glucose and insulin following an oral glucose load

2000 ◽  
Vol 84 (1) ◽  
pp. 19-23 ◽  
Author(s):  
P. J. Wood ◽  
M. U. Beer ◽  
G. Butler
Keyword(s):  
Molecular Weight ◽  
Blood Glucose ◽  
High Performance ◽  
Size Exclusion ◽  
Postprandial Blood Glucose ◽  
Oral Glucose ◽  
Oral Glucose Load ◽  
Glucose Load ◽  
Exclusion Chromatography ◽  
Insulin Responses

Data from clinical studies established that there was an inverse linear relationship between measures of postprandial blood glucose and insulin responses to an oral glucose load, consumed in a drink, and the logarithm of viscosity of the drink. These data have been re-analysed using concentration and molecular weight as the dependent variables. Molecular weight (M) of the β-glucans used was determined using high-performance size exclusion chromatography equipped with a triple detector system of right angle light scattering, viscometry and refractive index. A significant relationship between changes in peak blood glucose and a combination of logarithm of the concentration and logarithm of M was found.

scholarly journals A Novel Micronutrient Supplement to Preserve Male Metabolic Health and Prevent Fatty Liver (P21-007-19)

2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Saroj Khatiwada ◽  
Virginie Lecomte ◽  
Margaret Morris ◽  
Chris Maloney
Keyword(s):  
Lipid Metabolism ◽  
Fatty Liver ◽  
Insulin Release ◽  
Metabolic Health ◽  
Male Rats ◽  
Oral Glucose ◽  
Micronutrient Supplementation ◽  
Glucose Load ◽  
Triglyceride Accumulation ◽  
Obesogenic Diet

Abstract Objectives Growing evidence shows detrimental effects of paternal obesity on subsequent generations. We designed a micronutrient supplement whose components participate in one carbon metabolism and are anticipated to improve antioxidant capacity. Here, we studied the effects of the supplement on metabolic health and hepatic lipid metabolism in male rats consuming either a normal healthy diet or an obesogenic diet. Methods Male Sprague Dawley rats (3 weeks old, 17/group) were weaned onto control (CD) or high fat diet (HFD) with or without added micronutrient supplement (CDS; HFDS). After 12 weeks of diet, body composition was measured by magnetic resonance imaging, and blood samples were collected to assess supplementation levels. After 19 weeks of diet, oral glucose tolerance test (OGTT) was performed and plasma was collected to determine insulin release. At 27 weeks of diet, the rats were fasted and culled to harvest blood and tissues. Liver lipids and expression of genes involved in hepatic development and lipid metabolism were measured. Results Supplementation was confirmed by determining plasma folate concentrations (one component of supplement), which were increased by 26% across supplemented groups. HFD increased adiposity (P < 0.001) and body weight (P < 0.001), both of which were normalized in the HFDS group. HFD fed animals were glucose intolerant (blood glucose during OGTT, P = 0.005) compared to CD fed animals and had to release more insulin to clear an equivalent glucose load (insulin release during OGTT, P < 0.001). In comparison, the animals consuming HFDS needed less insulin to clear an equivalent glucose load (P < 0.001 vs HFD). HFD rats had larger livers than HFDS rats (P < 0.001). Micronutrient supplementation reduced hepatic triglyceride accumulation (P < 0.001) regardless of diet; this was accompanied by altered gene expression (particularly of CPT-1). Conclusions Dietary micronutrient supplementation prevented weight gain and adiposity, improved metabolic health, and excess lipid accumulation in liver in response to HFD. This provides evidence that the micronutrient supplement can preserve health and prevent fatty liver even when animals consume an obesogenic diet. Funding Sources NHMRC Australia project grant held by MJM and CAM. SK was supported by a UNSW international scholarship.

Enhanced myocardial depression in diabetic rats during E. coli sepsis

1987 ◽  
Vol 253 (2) ◽  
pp. H276-H282
Author(s):  
K. H. McDonough ◽  
R. W. Barbee ◽  
C. Dobrescu ◽  
C. H. Lang ◽  
J. J. Spitzer
Keyword(s):  
Blood Glucose ◽  
Fasting Blood Glucose ◽  
Systolic Pressure ◽  
Cardiac Performance ◽  
Diabetic Group ◽  
Control Group ◽  
Oral Glucose ◽  
Glucose Load ◽  
E Coli ◽  
Abnormal Response

The aim of this study was to determine whether diabetes enhanced the sensitivity of the myocardium to the deleterious effects of in vivo-administered Escherichia coli. Diabetes was induced in two groups of animals. One group received 70 mg/kg streptozotocin (iv) and exhibited a severe diabetes with elevated fasting and fed blood glucose concentrations and a markedly abnormal response to an oral glucose load. The second group received 45 mg/kg streptozotocin, was mildly diabetic (termed “latent” diabetes), and was characterized by normal fasting blood glucose but slightly elevated fed blood glucose and an abnormal response to a glucose load. A third group of rats received vehicle and served as time-matched control animals. Four weeks after induction of diabetes, all animals were catheterized under ether anesthesia and some received intraperitoneal injections of live E. coli. In vitro myocardial performance was assessed using the isolated, perfused working heart preparation. Ventricular function curves were generated by changing left atrial filling pressure and measuring changes in heart rate, cardiac output, and aortic peak systolic pressure. Cardiac performance in the severe diabetic group was depressed at the highest preload but was unchanged at lower preloads. Function in the latent diabetic group was not different from control. Sepsis induced a slight decrease in cardiac performance in the control group and resulted in larger reductions in the latent and severe diabetic groups. A depression in aortic flow was the major consequence of sepsis in the latent diabetic group, whereas decreased coronary flow was the primary change in the severe diabetic group.(ABSTRACT TRUNCATED AT 250 WORDS)

Psychiatric Aspects of Diabetes—a Physician's View

1981 ◽  
Vol 139 (6) ◽  
pp. 485-493 ◽  
Author(s):  
R. B. Tattersall
Keyword(s):  
Blood Glucose ◽  
Glucose Tolerance ◽  
Blood Glucose Level ◽  
Glucose Level ◽  
Common Factor ◽  
Fasting Blood Glucose ◽  
Normal Glucose Tolerance ◽  
Oral Glucose ◽  
Glucose Load ◽  
Normal Glucose

A raised blood sugar level no more defines a single entity than does a raised bilirubin or a low haemoglobin. Diabetes is a heterogenous group of disorders whose only common factor is hyperglycaemia (Tattersallet al, 1980). The classification of diabetes is being revised, although the changes are of more relevance to epidemiologists than clinicians. Previous standards of normal glucose tolerance were set too low, so that some people were labelled diabetic who had no symptoms and have proved on follow-up not to be at risk of developing complications such as retinopathy (i.e. they had a non-disease). Epidemiological evidence suggests that the cut-off point for ‘true’ diabetes (i.e. a condition which leads to complications and shortening of life span) is a blood glucose level two hours after a 50 G oral glucose load of 11.1 mMol/L (National Diabetes Data Group, 1979). This corresponds to a fasting blood glucose level of 7 mMol/L or below. Hence, a single blood glucose value, either in the fasting state or two hours after a 50 G glucose load, is enough to diagnose diabetes and glucose tolerance tests should hardly ever be necessary.

The Effect of Starvation and Diabetes on Glycolytic Enzymes in Human Adipose Tissue

1971 ◽  
Vol 41 (6) ◽  
pp. 545-553 ◽  
Author(s):  
D. J. Galton ◽  
J. P. D. Wilson
Keyword(s):  
Adipose Tissue ◽  
Blood Glucose ◽  
Negative Correlation ◽  
Marked Decrease ◽  
Fasting Blood Glucose ◽  
Human Adipose Tissue ◽  
Oral Glucose ◽  
Oral Glucose Load ◽  
Glucose Load ◽  
And Control

1. The activities of hexokinase (EC 2.7.1.1) and phosphofructokinase (EC 2.7.1.11) have been studied in homogenates of adipose tissue taken from human diabetics, fasting and control patients. 2. Three isoenzymes of hexokinase were observed with apparent Km values for glucose of 1.04 × 10-5 m, 2.6 × 10-4 m and 2.9 × 10-4 m, respectively. 3. No change in activity of hexokinase was found in adipose tissue of untreated diabetics (n = 22), treated diabetics (n = 13) or non-diabetic controls. However, fasting was associated with a decrease of approx. 40% in the activity of hexokinase in adipose tissue. 4. In contrast, there was a marked decrease in the activity of phosphofructokinase in adipose tissue from untreated diabetics (n = 24) which was restored to normal by either insulin therapy or treatment by hypoglycaemic drugs. 5. There was a negative correlation between the phosphofructokinase/hexokinase ratio in adipose tissue and the fasting blood glucose (P = 0.01) and the 2 h blood glucose (P = 0.03) after an oral glucose load (50 g). 6. The functional significance of the changes in enzyme activities is discussed in relation to the glucose intolerance of diabetes.

Effect of hyperglycaemia on glucose concentration of human nasal secretions

2004 ◽  
Vol 106 (5) ◽  
pp. 527-533 ◽  
Author(s):  
David M. WOOD ◽  
Amanda L. BRENNAN ◽  
Barbara J. PHILIPS ◽  
Emma H. BAKER
Keyword(s):  
Blood Glucose ◽  
Glucose Tolerance ◽  
Normal Glucose Tolerance ◽  
Oral Glucose ◽  
Oral Glucose Load ◽  
Glucose Load ◽  
Normal Glucose ◽  
Nasal Secretions ◽  
Blood Glucose Concentrations ◽  
Glucose Threshold

Glucose is not detectable in airways secretions of normoglycaemic volunteers, but is present at 1–9 mmol·l-1 in airways secretions from people with hyperglycaemia. These observations suggest the existence of a blood glucose threshold at which glucose appears in airways secretions, similar to that seen in renal and salivary epithelia. In the present study we determined the blood glucose threshold at which glucose appears in nasal secretions. Blood glucose concentrations were raised in healthy human volunteers by 20% dextrose intravenous infusion or 75 g oral glucose load. Nasal glucose concentrations were measured using modified glucose oxidase sticks as blood glucose concentrations were raised. Glucose appeared rapidly in nasal secretions once blood glucose was clamped at approx. 12 mmol·l-1 (n=6). On removal of the clamp, nasal glucose fell to baseline levels in parallel with blood glucose concentrations. An airway glucose threshold of 6.7–9.7 mmol·l-1 was identified (n=12). In six subjects with normal glucose tolerance, blood glucose concentrations rose above the airways threshold and nasal glucose became detectable following an oral glucose load. The presence of an airway glucose threshold suggests that active glucose transport by airway epithelial cells normally maintains low glucose concentrations in airways secretions. Blood glucose exceeds the airway threshold after a glucose load even in people with normal glucose tolerance, so it is likely that people with diabetes or hyperglycaemia spend a significant proportion of each day with glucose in their airways secretions.

A new concept for the evaluation of the blood glucose and insulin responses of healthy subjects following an oral glucose load

1974 ◽  
Vol 11 (4) ◽  
pp. 265-276 ◽  
Author(s):  
Olga Szabo ◽  
Werner Oppermann ◽  
Rafael A. Camerini-Dávalos ◽  
Carl Victor
Keyword(s):  
Blood Glucose ◽  
Healthy Subjects ◽  
Oral Glucose ◽  
Oral Glucose Load ◽  
Glucose Load ◽  
Insulin Responses

scholarly journals Physical Exercise and Glucose Tolerance in Nigerian University Students

2020 ◽  
Vol 6 (4) ◽  
pp. 432-438
Author(s):  
EO Taiwo ◽  
LO Thanni
Keyword(s):  
Blood Glucose ◽  
Physical Exercise ◽  
Glucose Tolerance ◽  
University Students ◽  
Fasting Blood Glucose ◽  
Oral Glucose ◽  
Oral Glucose Load ◽  
Glucose Load ◽  
Post Exercise ◽  
The Mean

Background: Studying post-prandial fluctuations in blood glucose has high physiological and clinical relevance. Physical exercise is known to influence this fluctuation. Objectives: To determine the gender difference in glucose tolerance following physical exercise in a population of university students. Methods: A total of 146 students were randomly selected from the Olabisi Onabanjo University, Sagamu, Ogun State, southwest Nigeria. Following overnight fast, Oral Glucose Tolerance Test (OGTT) was carried out. Pre-exercise, fasting blood glucose (FBG) was measured at 0 mins, and after oral glucose load of 75 grams at 30 minutes intervals for 2 hours. The physical exercise involved cycling using a bicycle ergometer for an hour. Thereafter, OGTT was conducted again 1 hour post-exercise. Results: The ages of the subjects ranged from 20 years to 49 years. There were 73 (50.0%) females. The mean Body Mass Index (BMI) of 23.5±1.1 kg/m2 for females was comparable to 22.8±0.3 kg/m2 for the males (p = 0.571). Seven (9.6%) females were obese compared to 2 (2.7%) males. The mean post-prandial blood glucose increased from 71.6±1.6 mg/dl to 90.8±1.8 mg/dl after oral glucose load and thereafter to 88.0±4.2 mg/dl at 120 minutes among males. The post-exercise blood glucose patterns included a significant reduction in the mean FBS for males compared to females (64.5±1.9 mg/dl vs. 71.7±1.9 mg/dl; p = 0.001) Conclusions: Glucose tolerance with exercise is better in females than males. The clinical importance of physical exercise lies in its effect on glucose tolerance.

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