A high antioxidant spice blend attenuates postprandial insulin responses and increases hydrophilic ORAC in vivo

At present, the best available estimators of β-cell mass in humans are those based on measurement of insulin levels or appearance rates in the circulation. In several animal models, these estimators have been validated against β-cell mass in lean animals. However, as many diabetic humans are obese, a correlation between in vivo tests and β-cell mass must be evaluated over a range of body weights to include different levels of insulin sensitivity. For this purpose, obese ( n = 10) and lean ( n = 25) Göttingen minipigs were studied. β-Cell mass had been reduced ( n = 16 lean, n = 5 obese) with a combination of nicotinamide (67 mg/kg) and streptozotocin (125 mg/kg), acute insulin response (AIR) to intravenous glucose and/or arginine was tested, pulsatile insulin secretion was evaluated by deconvolution ( n = 30), and β-cell mass was determined histologically. AIR to 0.3 ( r2= 0.4502, P < 0.0001) or 0.6 g/kg glucose ( r2= 0.6806, P < 0.0001), 67 mg/kg arginine ( r2= 0.5730, P < 0.001), and maximum insulin concentration ( r2= 0.7726, P < 0.0001) were all correlated to β-cell mass when evaluated across study groups, and regression lines were not different between lean and obese groups except for AIR to 0.3 g/kg glucose. Baseline pulse mass was not significantly correlated to β-cell mass across the study groups ( r2= 0.1036, NS), whereas entrained pulse mass did show a correlation across groups ( r2= 0.4049, P < 0.001). This study supports the use of in vivo tests of insulin responses to evaluate β-cell mass over a range of body weights in the minipig. Extensive stimulation of insulin secretion by a combination of glucose and arginine seems to give the best correlation to β-cell mass.

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Impaired glucose tolerance, glucagon, and insulin responses in mice lacking the loop diuretic-sensitive Nkcc2a transporter

AJP Cell Physiology ◽

10.1152/ajpcell.00144.2019 ◽

2019 ◽

Vol 317 (4) ◽

pp. C843-C856 ◽

Cited By ~ 1

Author(s):

Lisa Kelly ◽

Mohammed M. Almutairi ◽

Shams Kursan ◽

Romario Pacheco ◽

Eduardo Dias-Junior ◽

...

Keyword(s):

Glucose Homeostasis ◽

Β Cells ◽

Islet Size ◽

Low Levels ◽

Glucagon And Insulin ◽

Cell Expression ◽

Insulin Responses ◽

Gluconeogenic Substrate

The Na+K+2Cl− cotransporter-2 ( Nkcc2, Slc12a1) is abundantly expressed in the kidney and its inhibition with the loop-diuretics bumetanide and furosemide has been linked to transient or permanent hyperglycemia in mice and humans. Notably, Slc12a1 is expressed at low levels in hypothalamic neurons and in insulin-secreting β-cells of the endocrine pancreas. The present study was designed to determine if global elimination of one of the Slc12a1 products, i.e., Nkcc2 variant a ( Nkcc2a), the main splice version of Nkcc2 found in insulin-secreting β-cells, has an impact on the insulin and glucagon secretory responses and fuel homeostasis in vivo. We have used dynamic tests of glucose homeostasis in wild-type mice and mice lacking both alleles of Nkcc2a ( Nkcc2aKO) and assessed their islet secretory responses in vitro. Under basal conditions, Nkcc2aKO mice have impaired glucose homeostasis characterized by increased blood glucose, intolerance to the sugar, delayed/blunted in vivo insulin and glucagon responses to glucose, and increased glycemic responses to the gluconeogenic substrate alanine. Further, we provide evidence of conserved quantitative secretory responses of Nkcc2aKO islets within a context of increased islet size related to hyperplastic/hypertrophic glucagon- and insulin-positive cells (α-cells and β-cells, respectively), normal total islet Cl− content, and reduced β-cell expression of the Cl− extruder Kcc2.

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Altered insulin and glucagon secretion in perfused ethionine-treated rat pancreases

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.1982.243.6.e505 ◽

1982 ◽

Vol 243 (6) ◽

pp. E505-E511

Author(s):

K. V. Axen ◽

F. X. Pi-Sunyer

Keyword(s):

Insulin Secretion ◽

Glucagon Secretion ◽

Gastric Inhibitory Polypeptide ◽

Oral Glucose ◽

Secretory Function ◽

Acinar Structure ◽

Basal Insulin Secretion ◽

Pathogenic Action ◽

Insulin Responses

The endocrine secretory function of rat pancreases in which pancreatitis had been induced by feeding rats a 0.5% ethionine diet was investigated. Despite loss of 50% of exocrine tissue and widespread destruction of acinar structure, pancreatic insulin and glucagon contents and 4-h fasting plasma insulin levels in vivo did not differ significantly from those of food-restricted, weight-matched controls. Plasma glucose concentrations (fasting and after oral glucose) were significantly lower than control. In isolated, perfused ethionine-treated pancreases secretin failed to stimulate insulin secretion, whereas basal insulin secretion and insulin responses to glucose, arginine, gastric inhibitory polypeptide, vasoactive intestinal peptide (VIP), and somatostatin were similar to those of controls. Basal glucagon secretion was elevated in ethionine-treated pancreases, and glucagon outputs in response to arginine, VIP, and somatostatin showed a consistent trend toward higher levels than those of controls. These findings demonstrate that ethionine-induced pancreatitis selectively impairs islet secretory function. These effects may be due to damage to islet cell membranes by exocrine enzymes and/or a direct pathogenic action of ethionine on the islets.

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Efficacy of fibre additions to flatbread flour mixes for reducing post-meal glucose and insulin responses in healthy Indian subjects

British Journal Of Nutrition ◽

10.1017/s0007114517000277 ◽

2017 ◽

Vol 117 (3) ◽

pp. 386-394 ◽

Cited By ~ 13

Author(s):

Hanny M. Boers ◽

Katrina MacAulay ◽

Peter Murray ◽

Rajendra Dobriyal ◽

David J. Mela ◽

...

Keyword(s):

Wheat Flour ◽

South Asian ◽

Guar Gum ◽

Asian Population ◽

Postprandial Glucose ◽

South Asian Population ◽

Chickpea Flour ◽

Insulin Responses ◽

Postprandial Insulin

AbstractThe incidence of type 2 diabetes mellitus (T2DM) is increasing worldwide, including in developing countries, particularly in South Asia. Intakes of foods generating a high postprandial glucose (PPG) response have been positively associated with T2DM. As part of efforts to identify effective and feasible strategies to reduce the glycaemic impact of carbohydrate-rich staples, we previously found that addition of guar gum (GG) and chickpea flour (CPF) to wheat flour could significantly reduce the PPG response to flatbread products. On the basis of the results of an exploratory study with Caucasian subjects, we have now tested the effect of additions of specific combinations of CPF with low doses of GG to a flatbread flour mix for their impacts on PPG and postprandial insulin (PPI) responses in a South-Asian population. In a randomised, placebo-controlled full-cross-over design, fifty-six healthy Indian adults consumed flatbreads made with a commercial flatbread mix (100 % wheat flour) with no further additions (control) or incorporating 15 % CPF in combination with 2, 3 or 4 % GG. The flatbreads with CPF and 3 or 4 % GG significantly reduced PPG (both ≥15 % reduction in positive incremental AUC, P<0·01) and PPI (both ≥28 % reduction in total AUC, P<0·0001) compared with flatbreads made from control flour. These results confirm the efficacy and feasibility of the addition of CPF with GG to flatbread flour mixes to achieve significant reductions in both PPG and PPI in Indian subjects.

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Distinct Characteristics of Rye and Wheat Breads Impact on Their in Vitro Gastric Disintegration and in Vivo Glucose and Insulin Responses

Foods ◽

10.3390/foods5020024 ◽

2016 ◽

Vol 5 (4) ◽

pp. 24 ◽

Cited By ~ 9

Author(s):

Emilia Nordlund ◽

Kati Katina ◽

Hannu Mykkänen ◽

Kaisa Poutanen

Keyword(s):

Insulin Responses

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Hypoinsulinaemia in the lactating rat is caused by a decreased glycaemic stimulus to the pancreas

Journal of Endocrinology ◽

10.1677/joe.0.1250081 ◽

1990 ◽

Vol 125 (1) ◽

pp. 81-88 ◽

Cited By ~ 9

Author(s):

R. J. Madon ◽

D. M. Ensor ◽

D. J. Flint

Keyword(s):

Portal Vein ◽

Vena Cava ◽

Pregnant Rats ◽

Isolated Islets Of Langerhans ◽

Hepatic Portal Vein ◽

Hepatic Portal ◽

Insulin Responses ◽

Perifusion System

ABSTRACT An in-vitro perifusion system was devised in order to examine the secretory profiles of isolated islets of Langerhans, derived from different physiological states, when subjected to various stimuli relevant to lactation. Islets from pregnant rats secreted more insulin than did those from virgin animals; however, islets from lactating and virgin animals secreted similar amounts of insulin with all stimuli, including glucose, amino acids, cations and neurotransmitters. When virgin rats were pretreated for 5 days in vivo with GH or prolactin, insulin responses in vitro were unchanged. Cannulation of the hepatic portal vein and inferior vena cava in vivo revealed that both insulin and glucose concentrations were lower in the portal vein of the lactating rat compared with the virgin animal. It was therefore concluded that insulin concentrations are depressed during lactation as a consequence of the pancreas receiving a diminished glycaemic stimulus rather than because of any change in β-cell sensitivity. Journal of Endocrinology (1990) 125, 81–88

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Effect of acute and sub-chronic administration of the imidazoline compound S 22068 on in vivo glucose and insulin responses in normal lean CBA/Ca mice

General Pharmacology The Vascular System ◽

10.1016/s0306-3623(00)00059-8 ◽

2000 ◽

Vol 34 (3) ◽

pp. 183-191 ◽

Cited By ~ 6

Author(s):

Celia A Williams ◽

Mei-Fen Shih ◽

Peter V Taberner

Keyword(s):

Chronic Administration ◽

Insulin Responses

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The Mechanism of Action of Guar Gum in Improving Glucose Tolerance in Man

Clinical Science ◽

10.1042/cs0660329 ◽

1984 ◽

Vol 66 (3) ◽

pp. 329-336 ◽

Cited By ~ 187

Author(s):

N. A. Blackburn ◽

J. S. Redfern ◽

H. Jarjis ◽

A. M. Holgate ◽

I. Hanning ◽

...

Keyword(s):

Gastric Emptying ◽

Glucose Tolerance ◽

Guar Gum ◽

Glucose Absorption ◽

Oral Glucose ◽

Electrical Measurements ◽

Fluid Convection ◽

Insulin Responses

1. Experiments were carried out in human volunteers to investigate the mechanism by which guar gum improves glucose tolerance. 2. Guar reduced both plasma glucose and insulin responses to an oral glucose load, and delayed gastric emptying. However, there was no correlation between changes in individual blood glucose responses and changes in gastric emptying rates induced by guar. 3. With a steady-state perfusion technique, glucose absorption was found to be significantly reduced during perfusion of the jejunum with solutions containing guar, but returned to control values during subsequent guar-free perfusions. 4. Preperfusing the intestine with guar did not affect electrical measurements of unstirred layer thickness in the human jejunum in vivo.. 5. Experiments in vitro established that glucose diffusion out of a guar/glucose mixture was delayed under conditions of constant stirring. 6. We conclude that guar improves glucose tolerance predominantly by reducing glucose absorption in the small intestine. It probably does this by inhibiting the effects of intestinal motility on fluid convection.

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