Goji Berry (Lycium barbarum) Supplementation during Pregnancy Influences Insulin Sensitivity in Rabbit Does but Not in Their Offspring

This study investigated the effects of Goji berry (Lycium barbarum) dietary supplementation during pregnancy on insulin sensitivity of rabbit does and their offspring. Starting from two months before the artificial insemination, 75 New Zealand White does were fed only commercial standard diet (C) or supplemented with 1% (G1) and 3% (G3) of Goji berries. Their offspring received a standard diet but kept the nomenclature of the mother’s group. Fasting and intravenous glucose tolerance test-derived indices were estimated at 21 days of pregnancy on rabbit does and at 90 days of age on the offspring. No difference was found in the fasting indices, while the diet modulated the response to glucose load of rabbit does. In particular, G3 group had the lowest glucose concentrations 5 min after the bolus administration (p < 0.05) and, as a result, differed in the parameters calculated during the elimination phase such as the elimination rate constant (Kel), the half-life of the exogenous glucose load (t1/2), and apparent volume of distribution (Vd; for all, p < 0.05). The high dose of Goji supplementation could thus enhance the first-phase glucose-induced insulin secretion. Findings on the offspring were inconsistent and therefore a long-term effect of Goji supplementation during pregnancy could not be demonstrated. Further study on the effect of Goji on the secretory pathway of insulin could clarify its hypoglycaemic action, while different protocols are needed to investigate its potential effects on foetal programming.

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Assessment of Insulin Sensitivity in Man: A Comparison of Minimal Model- and Euglycaemic Clamp-Derived Measures in Health and Heart Failure

Clinical Science ◽

10.1042/cs0860317 ◽

1994 ◽

Vol 86 (3) ◽

pp. 317-322 ◽

Cited By ~ 52

Author(s):

Jonathan W. Swan ◽

Christopher Walton ◽

Ian F. Godsland

Keyword(s):

Heart Failure ◽

Insulin Sensitivity ◽

Minimal Model ◽

Glucose Tolerance Test ◽

Tolerance Test ◽

Intravenous Glucose Tolerance Test ◽

High Dose ◽

Sensitivity Index ◽

Intravenous Glucose ◽

Intravenous Glucose Tolerance

1. Simplified protocols for the measurement of insulin resistance will facilitate studies of this potentially important variable. 2. Using the euglycaemic clamp as the reference technique, we have assessed the validity of the insulin sensitivity index (inversely related to insulin resistance) obtained using a high-dose (500 mg/kg), unmodified intravenous glucose tolerance test with a 16 point sampling schedule and analysis using the minimal model of glucose disappearance. The two methods were compared in 10 clinically normal subjects and five patients with severe heart failure secondary to coronary heart disease. 3. The insulin sensitivity index of the minimal model was compared with four clamp-derived measures. Correlation coefficients of 0.72–0.92 (P < 0.01−P < 0.001) were obtained between the two methods over a wide range of insulin sensitivity [model values 1.03–14.63 min−1/(pmol/l) × 10−5]. Patients with heart failure had the lowest measures of insulin sensitivity. 4. The high-dose, unmodified intravenous glucose tolerance test with minimal model analysis is a straightforward and economical clinical procedure and provides a valid measure of insulin sensitivity, in health and disease.

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PACAP stimulates insulin secretion but inhibits insulin sensitivity in mice

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.1998.274.5.e834 ◽

1998 ◽

Vol 274 (5) ◽

pp. E834-E842 ◽

Cited By ~ 16

Author(s):

Karin Filipsson ◽

Giovanni Pacini ◽

Anton J. W. Scheurink ◽

Bo Ahrén

Keyword(s):

Insulin Secretion ◽

Insulin Sensitivity ◽

Elimination Rate ◽

Insulin Response ◽

Area Under The Curve ◽

Glucose Disposal ◽

Sensitivity Index ◽

Maximal Effect ◽

Intravenous Glucose

Although pituitary adenylate cyclase-activating polypeptide (PACAP) stimulates insulin secretion, its net influence on glucose homeostasis in vivo has not been established. We therefore examined the action of PACAP-27 and PACAP-38 on insulin secretion, insulin sensitivity, and glucose disposal as derived from the minimal model of glucose disappearance during an intravenous glucose tolerance test in anesthetized mice. PACAP-27 and PACAP-38 markedly and equipotently potentiated glucose-stimulated insulin secretion, with a half-maximal effect at 33 pmol/kg. After PACAP-27 or PACAP-38 (1.3 nmol/kg), the acute (1–5 min) insulin response was 3.8 ± 0.4 nmol/l (PACAP-27) and 3.3 ± 0.3 nmol/l (PACAP-38), respectively, vs. 1.4 ± 0.1 nmol/l after glucose alone ( P < 0.001), and the total area under the curve for insulin (AUCinsulin) was potentiated by 60% ( P < 0.001). In contrast, PACAP-27 and PACAP-38 reduced the insulin sensitivity index (SI) [0.23 ± 0.04 10−4min−1/(pmol/l) for PACAP-27 and 0.29 ± 0.06 10−4min−1/(pmol/l) for PACAP-38 vs. 0.46 ± 0.02 10−4min−1/(pmol/l) for controls ( P < 0.01)]. Furthermore, PACAP-27 or PACAP-38 did not affect glucose elimination determined as glucose half-time or the glucose elimination rate after glucose injection or the area under the curve for glucose. Moreover, glucose effectiveness and the global disposition index (AUCinsulin times SI) were not affected by PACAP-27 or PACAP-38. Finally, when given together with glucose, PACAP-27 did not alter plasma glucagon or norepinephrine levels but significantly increased plasma epinephrine levels. We conclude that PACAP, besides its marked stimulation of insulin secretion, also inhibits insulin sensitivity in mice, the latter possibly explained by increased epinephrine. This complex action explains why the peptide does not enhance glucose disposal.

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A subcutaneously implanted glucose sensor: sensor signal and blood glucose following intravenous glucose load or insulin administration in normal and diabetic rats

Acta Endocrinologica ◽

10.1530/acta.0.117s181 ◽

1988 ◽

Vol 117 (4_Suppl) ◽

pp. S181 ◽

Cited By ~ 1

Author(s):

M. DOLDERER ◽

R. V. WARHADPANDE ◽

C. ZAWADIL ◽

H. ZIER ◽

W. KERNER ◽

...

Keyword(s):

Blood Glucose ◽

Glucose Sensor ◽

Diabetic Rats ◽

Insulin Administration ◽

Glucose Load ◽

Sensor Signal ◽

Intravenous Glucose ◽

Intravenous Glucose Load

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Insulin response to an intravenous glucose load during development of obesity in gold thioglucose-injected mice

Diabetes ◽

10.2337/diabetes.42.8.1153 ◽

1993 ◽

Vol 42 (8) ◽

pp. 1153-1158 ◽

Cited By ~ 2

Author(s):

S. C. Blair ◽

I. D. Caterson ◽

G. J. Cooney

Keyword(s):

Insulin Response ◽

Glucose Load ◽

Intravenous Glucose ◽

Gold Thioglucose ◽

Intravenous Glucose Load

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Comparison of estimates of insulin sensitivity from minimal model analysis of the insulin-modified frequently sampled intravenous glucose tolerance test and the isoglycemic hyperinsulinemic clamp in subjects with NIDDM

Diabetes ◽

10.2337/diabetes.44.6.631 ◽

1995 ◽

Vol 44 (6) ◽

pp. 631-635 ◽

Cited By ~ 8

Author(s):

P. A. Coates ◽

S. D. Luzio ◽

P. Brunel ◽

D. R. Owens

Keyword(s):

Insulin Sensitivity ◽

Glucose Tolerance ◽

Minimal Model ◽

Glucose Tolerance Test ◽

Tolerance Test ◽

Model Analysis ◽

Intravenous Glucose Tolerance Test ◽

Intravenous Glucose ◽

Intravenous Glucose Tolerance

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Association of plasma acylcarnitines with insulin sensitivity, insulin secretion, and prediabetes in a biracial cohort

Experimental Biology and Medicine ◽

10.1177/15353702211009493 ◽

2021 ◽

pp. 153537022110094

Author(s):

Ibiye Owei ◽

Nkiru Umekwe ◽

Frankie Stentz ◽

Jim Wan ◽

Sam Dagogo-Jack

Keyword(s):

Type 2 Diabetes ◽

Insulin Secretion ◽

Insulin Sensitivity ◽

Glucose Tolerance ◽

Intravenous Glucose Tolerance Test ◽

Cross Sectional ◽

Parental History ◽

Intravenous Glucose

The ability to predict prediabetes, which affects ∼90 million adults in the US and ∼400 million adults worldwide, would be valuable to public health. Acylcarnitines, fatty acid metabolites, have been associated with type 2 diabetes risk in cross-sectional studies of mostly Caucasian subjects, but prospective studies on their link to prediabetes in diverse populations are lacking. Here, we determined the association of plasma acylcarnitines with incident prediabetes in African Americans and European Americans enrolled in a prospective study. We analyzed 45 acylcarnitines in baseline plasma samples from 70 adults (35 African-American, 35 European-American) with incident prediabetes (progressors) and 70 matched controls (non-progressors) during 5.5-year (mean 2.6 years) follow-up in the Pathobiology of Prediabetes in a Biracial Cohort (POP-ABC) study. Incident prediabetes (impaired fasting glucose/impaired glucose tolerance) was confirmed with OGTT. We measured acylcarnitines using tandem mass spectrometry, insulin sensitivity by hyperinsulinemic euglycemic clamp, and insulin secretion using intravenous glucose tolerance test. The results showed that progressors and non-progressors during POP-ABC study follow-up were concordant for 36 acylcarnitines and discordant for nine others. In logistic regression models, beta-hydroxy butyryl carnitine (C4-OH), 3-hydroxy-isovaleryl carnitine/malonyl carnitine (C5-OH/C3-DC), and octenoyl carnitine (C8:1) were the only significant predictors of incident prediabetes. The combined cut-off plasma levels of <0.03 micromol/L for C4-OH, <0.03 micromol/L for C5-OH/C3-DC, and >0.25 micromol/L for C8:1 acylcarnitines predicted incident prediabetes with 81.9% sensitivity and 65.2% specificity. Thus, circulating levels of one medium-chain and two short-chain acylcarnitines may be sensitive biomarkers for the risk of incident prediabetes among initially normoglycemic individuals with parental history of type 2 diabetes.

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Effect of training on insulin binding to rat skeletal muscle sarcolemmal vesicles

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.1986.250.5.e570 ◽

1986 ◽

Vol 250 (5) ◽

pp. E570-E575

Author(s):

G. K. Grimditch ◽

R. J. Barnard ◽

S. A. Kaplan ◽

E. Sternlicht

Keyword(s):

Skeletal Muscle ◽

Insulin Sensitivity ◽

Exercise Training ◽

Insulin Binding ◽

Whole Body ◽

Rat Skeletal Muscle ◽

Binding Studies ◽

Muscle Enzyme ◽

Intravenous Glucose ◽

High Affinity

We examined the hypothesis that the exercise training-induced increase in skeletal muscle insulin sensitivity is mediated by adaptations in insulin binding to sarcolemmal (SL) insulin receptors. Insulin binding studies were performed on rat skeletal muscle SL isolated from control and trained rats. No significant differences were noted between groups in body weight or fat. An intravenous glucose tolerance test showed an increase in whole-body insulin sensitivity with training, and specific D-glucose transport studies on isolated SL vesicles indicated that this was due in part to adaptations in skeletal muscle. Enzyme marker analyses revealed no differences in yield, purity, or contamination of SL membranes between the two groups. Scatchard analyses indicated no significant differences in the number of insulin binding sites per milligram SL protein on the high-affinity (15.0 +/- 4.1 vs. 18.1 +/- 6.4 X 10(9)) or on the low-affinity portions (925 +/- 80 vs. 884 +/- 106 X 10(9)) of the curves. The association constants of the high-affinity (0.764 +/- 0.154 vs. 0.685 +/- 0.264 X 10(9) M-1) and of the low affinity sites (0.0096 +/- 0.0012 vs. 0.0102 +/- 0.0012 X 10(9) M-1) also were similar. These results do not support the hypothesis that the increased sensitivity to insulin after exercise training is due to changes in SL insulin receptor binding.

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