scholarly journals Modifications of gastric inhibitory polypeptide (GIP) secretion in man by a high-fat diet

1988 ◽  
Vol 59 (3) ◽  
pp. 373-380 ◽  
Author(s):  
L. M. Morgan ◽  
S. M. Hampton ◽  
J. A. Tredger ◽  
R. Cramb ◽  
V. Marks

1. Five healthy volunteers (usual fat intake 103) (SE 9) g/d and energy intake 9855 (SE 937) kJ/d were given on two separate occasions (a) 100 g oral glucose and (b) sufficient intravenous (IV) glucose to obtain similar arterialized plasma glucose levels to those after oral glucose.2. Subjects increased their fat intake by 68 (SE 9·6) % for 28 d by supplementing their diet with 146 ml double cream/d (fat intake on high-fat diet (HFD) 170 (SE 8) g/d; energy intake 12347 (SE 770)).3. The 100 g oral glucose load was repeated and IV glucose again given in quantities sufficient to obtain similar arterialized blood glucose levels. Immunoreactive plasma insulin, C-peptide and gastric inhibitory polypeptide (GIP) were measured.4. Plasma GIP levels were higher following oral glucose after the HFD (area under plasma GIP curve 0–180 min 1660 (SE 592) v. 2642 (SE 750) ng/l.h for control and HFD respectively; P < 0·05). Both insulin and C-peptide levels were significantly higher after oral than after IV glucose (P < 0·01) but neither were affected by the HFD. Glucose levels were lower following the HFD after both oral and IV glucose (area under plasma glucose curve 0–180 min, following oral glucose 6·7 (SE 0·3) mmol/l.h for control and 4·2 (SE 0·6) mmol/l.h for HFD; P < 0·01).5. Glucose-stimulated GIP secretion was thus enhanced by the HFD. Insulin secretion in response to oral glucose was unchanged, in spite of an improvement in glucose tolerance.6. The improvement in glucose tolerance post-HFD could possibly be due to a GIP-mediated inhibition of hepatic glycogenolysis, or a decreased rate of glucose uptake from the small intestine.

Nutrients ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 1666
Author(s):  
Dean S. Ross ◽  
Tzu-Hsuan Yeh ◽  
Shalinie King ◽  
Julia Mathers ◽  
Mark S. Rybchyn ◽  
...  

Increased risks of skeletal fractures are common in patients with impaired glucose handling and type 2 diabetes mellitus (T2DM). The pathogenesis of skeletal fragility in these patients remains ill-defined as patients present with normal to high bone mineral density. With increasing cases of glucose intolerance and T2DM it is imperative that we develop an accurate rodent model for further investigation. We hypothesized that a high fat diet (60%) administered to developing male C57BL/6J mice that had not reached skeletal maturity would over represent bone microarchitectural implications, and that skeletally mature mice would better represent adult-onset glucose intolerance and the pre-diabetes phenotype. Two groups of developing (8 week) and mature (12 week) male C57BL/6J mice were placed onto either a normal chow (NC) or high fat diet (HFD) for 10 weeks. Oral glucose tolerance tests were performed throughout the study period. Long bones were excised and analysed for ex vivo biomechanical testing, micro-computed tomography, 2D histomorphometry and gene/protein expression analyses. The HFD increased fasting blood glucose and significantly reduced glucose tolerance in both age groups by week 7 of the diets. The HFD reduced biomechanical strength, both cortical and trabecular indices in the developing mice, but only affected cortical outcomes in the mature mice. Similar results were reflected in the 2D histomorphometry. Tibial gene expression revealed decreased bone formation in the HFD mice of both age groups, i.e., decreased osteocalcin expression and increased sclerostin RNA expression. In the mature mice only, while the HFD led to a non-significant reduction in runt-related transcription factor 2 (Runx2) RNA expression, this decrease became significant at the protein level in the femora. Our mature HFD mouse model more accurately represents late-onset impaired glucose tolerance/pre-T2DM cases in humans and can be used to uncover potential insights into reduced bone formation as a mechanism of skeletal fragility in these patients.


2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Jihye Lee ◽  
Seong-Ho Lee

Abstract Objectives Patchouli alcohol is a sesquiterpene alcohol found in Pogostemon cablin. Recently, we observed that patchouli alcohol reduced lipid accumulation in differentiated 3T3-L1 adipocytes and increased glucose uptake in differentiated C2C12 myocytes. This study was designed to investigate anti-obese and anti-diabetic activities of patchouli alcohol using high fat diet-induced obese mouse model. Methods Forty-eight 5-week old C57BL/6 J male mice were assigned into four groups and fed with 1) normal diet (control), 2) high fat diet, 3) high fat diet with gavaging 25 mg of patchouli alcohol/kg body weight and 4) high fat diet with gavaging 50 mg of patchouli alcohol/kg body weight. High fat diet or control diets were provided to each treatment group for four weeks and then different doses of patchouli alcohol (0, 25 or 50 mg/kg body weight) was orally administered for following 8 weeks with the diet. At age of week 17, all animals were sacrificed, fat tissues were collected, and tissue weight was measured. In addition, twenty C57BL/6 J male mice were assigned into the same treatment groups above. At the end of the 8 weeks (age of week 17), the mice were fasted for 12 h and the oral glucose tolerance test was performed after intraperitoneal injection of 2 g of anhydrous glucose/kg body weight. The blood was collected from tail at 0, 15, 30, 90 and 120 min after injection and blood glucose level was analyzed using glucose meter. Results Treatment of patchouli alcohol (50 mg/kg body weight) significantly reduced body weight and accumulation of body fat pads which was highly induced by feeding of high fat diet. An analysis of individual fat pad weights (expressed as mg weight of fat pad/g body weight) revealed a significant decrease of epididymal and retroperitoneal fat pad in patchouli alcohol-treated mice whereas brown adipose tissue were not significantly altered. And, slightly improved glucose tolerance was observed at 90 and 120 minutes after glucose injection in mice treated with patchouli alcohol (50 mg/kg body weight) compared to those fed with high fat diet alone. Conclusions We propose a potential use of patchouli alcohol as an anti-obesity compound in obese population. Funding Sources NIFA Hatch grant. Supporting Tables, Images and/or Graphs


Nutrients ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 3192
Author(s):  
Chiu-Li Yeh ◽  
Po-Jen Yang ◽  
Po-Chu Lee ◽  
Jin-Ming Wu ◽  
Po-Da Chen ◽  
...  

Obesity is a health problem associated with many metabolic disorders. Weight reduction can effectively alleviate obesity-associated complications. Sleeve gastrectomy is a commonly used bariatric surgery and is considered safe and effective for improving outcomes. Glutamine (GLN) is an amino acid with anti-oxidative and anti-inflammatory properties. This study used a mouse model of sleeve gastrectomy to investigate the impacts of intravenous GLN administration on glucose tolerance and adipocyte inflammation short-term after surgery. C57BL6 male mice were divided into normal control (NC) and high-fat diet groups. The high-fat diet provided 60% of energy from fat for 10 weeks to induce obesity. Mice fed the high-fat diet were then assigned to a sham (SH) or sleeve gastrectomy with saline (S) or GLN (G) groups. The S group was intravenously injected with saline, while the G group was administered GLN (0.75 g/kg body weight) via a tail vein postoperatively. Mice in the experimental groups were sacrificed on day 1 or 3 after the surgery. Results showed that obesity resulted in fat accumulation, elevated glucose levels, and adipokines production. Sleeve gastrectomy aggravated expressions of inflammatory cytokine and macrophage infiltration markers, cluster of differentiation 68 (CD68), epidermal growth factor-like module-containing mucin-like hormone receptor-like 1 (EMR-1), and macrophage chemoattractant protein-1, in adipose tissues. Treatment of obese mice with GLN downregulated hepatic proteomic profiles associated with the gluconeogenesis pathway and improved glucose tolerance. Moreover, macrophage infiltration and adipose tissue inflammation were attenuated after the sleeve gastrectomy. These findings imply that postoperative intravenous GLN administration may improve glucose tolerance and attenuate inflammation shortly after the bariatric surgery in subjects with obesity.


2015 ◽  
Vol 47 ◽  
pp. 289-290
Author(s):  
Cody G. Durrer ◽  
Zhongxiao Wan ◽  
Nia Lewis ◽  
Philip N. Ainslie ◽  
Nathan T. Jenkins ◽  
...  

2008 ◽  
Vol 295 (2) ◽  
pp. E401-E406 ◽  
Author(s):  
Muhammad A. Abdul-Ghani ◽  
Masafumi Matsuda ◽  
Rucha Jani ◽  
Christopher P. Jenkinson ◽  
Dawn K. Coletta ◽  
...  

To assess the relationship between the fasting plasma glucose (FPG) concentration and insulin secretion in normal glucose tolerance (NGT) and impaired glucose tolerance (IGT) subjects, 531 nondiabetic subjects with NGT ( n = 293) and IGT ( n = 238; 310 Japanese and 232 Mexican Americans) received an oral glucose tolerance test (OGTT) with measurement of plasma glucose, insulin, and C-peptide every 30 min. The insulin secretion rate was determined by plasma C-peptide deconvolution. Insulin sensitivity (Matsuda index) was measured from plasma insulin and glucose concentrations. The insulin secretion/insulin resistance (IS/IR) or disposition index was calculated as ΔISR/ΔG ÷ IR. As FPG increased in NGT subjects, the IS/IR index declined exponentially over the range of FPG from 70 to 125 mg/dl. The relationship between the IS/IR index and FPG was best fit with the equation: 28.8 exp(−0.036 FPG). For every 28 mg/dl increase in FPG, the IS/IR index declined by 63%. A similar relationship between IS/IR index and FPG was observed in IGT. However, the decay constant was lower than in NGT. The IS/IR index for early-phase insulin secretion (0–30 min) was correlated with the increase in FPG in both NGT and IGT ( r = −0.43, P < 0.0001 and r = −0.20, P = 0.001, respectively). However, the correlation between late-phase insulin secretion (60–120 min) and FPG was not significant. In conclusion, small increments in FPG, within the “normal” range, are associated with a marked decline in glucose-stimulated insulin secretion and the decrease in insulin secretion with increasing FPG is greater in subjects with NGT than IGT and primarily is due to a decline in early-phase insulin secretion.


2021 ◽  
Author(s):  
Haopeng Lin ◽  
Nancy Smith ◽  
Aliya F Spigelman ◽  
Kunimasa Suzuki ◽  
Mourad Ferdaoussi ◽  
...  

SUMOylation reduces oxidative stress and preserves islet mass at the expense of robust insulin secretion. To investigate a role for the deSUMOylating enzyme <u>sen</u>trin-specific <u>p</u>rotease <u>1</u> (SENP1) following metabolic stress, we put pancreas/gut-specific SENP1 knockout mice (pSENP1-KO) on a high fat diet (HFD). Male pSENP1-KO mice were more glucose intolerant following HFD than littermate controls, but only in response to oral glucose. A similar phenotype was observed in females. Plasma glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like-peptide 1 (GLP-1) responses were identical in pSENP1-KO and -WT littermates, including the HFD-induced upregulation of GIP responses. Islet mass was not different, but insulin secretion and β-cell exocytotic responses to the GLP-1 receptor agonist Exendin-4 (Ex4) and GIP were impaired in islets lacking SENP1. Glucagon secretion from pSENP1-KO islets was also reduced, so we generated β-cell-specific SENP1 knockout mice (βSENP1-KO). These phenocopied the pSENP1-KO mice with selective impairment in oral glucose tolerance following HFD, preserved islet mass expansion, and impaired β-cell exocytosis and insulin secretion to Ex4 and GIP without changes in cAMP or Ca<sup>2+</sup> levels. Thus, β-cell SENP1 limits oral glucose intolerance following HFD by ensuring robust insulin secretion at a point downstream of incretin signaling.


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