scholarly journals Changes induced by sucrose administration on glucose metabolism in pancreatic islets in normal hamsters

2001 ◽  
Vol 171 (3) ◽  
pp. 551-556 ◽  
Author(s):  
ML Massa ◽  
MI Borelli ◽  
H Del Zotto ◽  
JJ Gagliardino

We correlated the changes in glucose-induced insulin secretion with those observed in glucose metabolism and hexokinase/glucokinase activity in islets from normal sucrose-fed hamsters. Blood glucose and insulin levels were measured in normal male hamsters fed with (S5) or without (C5) 10% sucrose in the drinking water for 5 weeks. Isolated islets (collagenase digestion) from both groups of animals were used to study insulin secretion, (14)CO(2) and (3)H(2)O production from D-[U-(14)C]-glucose and D-[5-(3)H]-glucose respectively, with 3.3 or 16.7 mM glucose in the medium, and hexokinase/glucokinase activity (fluorometric assay) in islet homogenates. Whereas S5 and C5 animals had comparable normal blood glucose levels, S5 showed higher insulin levels than C5 hamsters (2.3+/-0.1 vs 0.6+/-0.03 ng/ml, P<0.001). Islets from S5 hamsters released significantly more insulin than C5 islets in the presence of low and high glucose (3.3 mM glucose: 0.77+/-0.04 vs 0.20+/-0.06 pg/ng DNA/min, P<0.001; 16.7 mM glucose: 2.77+/-0.12 vs 0.85+/-0.06 pg/ng DNA/min, P<0.001) and produced significantly higher amounts of (14)CO(2) and (3)H(2)O at both glucose concentrations ((14)CO(2): 3.3 mM glucose: 0.27+/-0.01 vs 0.18+/-0.01, P<0.001; 16.7 mM glucose: 1.44+/-0.15 vs 0.96+/-0.08, P<0.02; (3)H(2)O: 3.3 mM glucose: 0.31+/-0.02 vs 0.15+/-0.01, P<0.001; 16.7 mM glucose: 1.46+/-0.20 vs 0.76+/-0.05 pmol glucose/ng DNA/min, P<0.005). The hexokinase K(m) and V(max) values from S5 animals were significantly higher than those from C5 ones (K(m): 100.14+/-7.01 vs 59.90+/- 3.95 microM, P<0.001; V(max): 0.010+/-0.0005 vs 0.008+/- 0.0006 pmol glucose/ng DNA/min, P<0.02). Conversely, the glucokinase K(m) value from S5 animals was significantly lower than in C5 animals (K(m): 15.31+/-2.64 vs 35.01+/-1.65 mM, P<0.001), whereas V(max) figures were within a comparable range in both groups (V(max): 0.048+/-0.009 vs 0.094+/-0.035 pmol glucose/ng DNA/min, not significant). The glucose phosphorylation ratio measured at 1 and 100 mM (hexokinase/glucokinase ratio) was significantly higher in S5 (0.26+/-0.02) than in C5 animals (0.11+/-0.01, P<0.005), and it was attributable to an increase in the hexokinase activity in S5 animals. In conclusion, sucrose administration increased the hexokinase/glucokinase activity ratio in the islets, which would condition the increase in glucose metabolism by beta-cells, and in beta-cell sensitivity and responsiveness to glucose. These results support the concept that increased hexokinase rather than glucokinase activity causes the beta-cell hypersensitivity to glucose, hexokinase being metabolically more active than glucokinase to up-regulate beta-cell function.

2014 ◽  
Vol 11 (1) ◽  
pp. 24-31
Author(s):  
I I Dedov ◽  
G A Melnichenko ◽  
E A Troshina ◽  
N V Mazurina ◽  
N A Ogneva ◽  
...  

We’ve studied a carbohydrate metabolism in morbidly obese (MO) patients and the patients after bariatric surgery. The patients of the 1st group had BMI40 (n=22) and no history of diabetes mellitus. Patients after biliopancreatic diversion (BPD) performed for MO were included in the 2nd group (n=23). The 3rd group was a control group of normal weight healthy subjects (n=22). Blood glucose levels, insulin, GLP-1, GIP and glucagon during the OGTT (with 75 g of glucose) at 0, 30, 60 and 120 minutes were measured in all patients. In MO group fasting glucose levels were the highest. Impaired glucose metabolism was revealed in 68.2% of patients (n=10). Impaired fasting glucose (IFG) was diagnosed in 4 cases (18.2%), impaired glucose tolerance (IGT) in 11 patients (50%). In the BPD postprandial blood glucose levels (120 min) were lower if compared to the other groups. In 4 individuals (17.4%) we found postprandial hypoglycemia (2.8 mmol/l). Patients of the MO group had the highest fasting insulin levels and HOMA-IR (p0.001). The maximum of insulin concentration was seen on minute 30 of the OGTT in the 2nd and 3rd groups, and it was significantly higher in the post-bariatric patients (p=0.026). In MO group the maximum of the plasma insulin levels were on the 60th minute and were still elevated after 120 minutes. Fasting and stimulated (on the 30th minute) levels of GLP-1 were significantly higher after BPD (р=0.037 and p=0.022 at 0 and 30 min, respectively). Morbidly obese patients had higher fasting and stimulated GIP. Fasting glucagon concentrations were similar in the surgical and control groups, while the people with MO had higher initial levels of glucagon (p=0.013) and it was not suppressed during the OGTT (p=0.076). Glucose intolerance and insulin resistance incidence was higher in MO patients. Hyperglucagonemia, increased GIP and decreased GLP-1 levels are observed in MO patients. Stimulated plasma insulin and GLP-1 concentrations were significantly increased in patients who underwent BPD, and may cause postprandial hypoglycemia.


2020 ◽  
Vol 11 ◽  
pp. 204201882096506
Author(s):  
Basma Haris ◽  
Saras Saraswathi ◽  
Khalid Hussain

Hyperinsulinaemic hypoglycaemia (HH) is a biochemical finding of low blood glucose levels due to the dysregulation of insulin secretion from pancreatic β-cells. Under normal physiological conditions, glucose metabolism is coupled to β-cell insulin secretion so that blood glucose levels are maintained within the physiological range of 3.5–5.5 mmol/L. However, in HH this coupling of glucose metabolism to insulin secretion is perturbed so that insulin secretion becomes unregulated. HH typically occurs in the neonatal, infancy and childhood periods and can be due to many different causes. Adults can also present with HH but the causes in adults tend to be different. Somatostatin (SST) is a peptide hormone that is released by the delta cells (δ-cells) in the pancreas. It binds to G protein-coupled SST receptors to regulate a variety of location-specific and selective functions such as hormone inhibition, neurotransmission and cell proliferation. SST plays a potent role in the regulation of both insulin and glucagon secretion in response to changes in glucose levels by negative feedback mechanism. The half-life of SST is only 1–3 min due to quick degradation by peptidases in plasma and tissues. Thus, a direct continuous intravenous or subcutaneous infusion is required to achieve the therapeutic effect. These limitations prompted the discovery of SST analogues such as octreotide and lanreotide, which have longer half-lives and therefore can be administered as injections. SST analogues are used to treat different forms of HH in children and adults and therapeutic effect is achieved by suppressing insulin secretion from pancreatic β-cells by complex mechanisms. These treatments are associated with several side effects, especially in the newborn period, with necrotizing enterocolitis being the most serious side effect and hence SS analogues should be used with extreme caution in this age group.


1993 ◽  
Vol 264 (3) ◽  
pp. E441-E449 ◽  
Author(s):  
E. Christiansen ◽  
H. B. Andersen ◽  
K. Rasmussen ◽  
N. J. Christensen ◽  
K. Olgaard ◽  
...  

beta-Cell function and glucose metabolism were studied in eight insulin-dependent diabetic recipients of combined segmental pancreas and kidney transplant with peripheral insulin delivery (Px), in eight nondiabetic kidney-transplant individuals (Kx), and in eight normal subjects (Ns) after three consecutive mixed meals. All subjects had normal fasting plasma glucose, but increased basal levels of C-peptide were demonstrated in the transplant groups (P < 0.05 relative to Ns). Postprandial hyperglycemia was increased 14% in Kx and 32% in Px (P < 0.05), whereas compared with Ns postprandial C-peptide levels were increased three- and twofold, respectively, in Kx and Px (P < 0.05). Compared with Ns basal insulin secretion rate (combined model) was increased 2-fold in Kx and 1.4-fold in Px (P < 0.05). Maximal insulin secretion rate was reduced 25% in Px compared with Kx (P < 0.05) but not different from that of Ns (P NS). Also, maximal insulin secretion rate occurred later in Px than in controls (Tmax: Px 50 min, Kx 30 min, and Ns 32 min; P < 0.05). The total integrated insulin secretion was increased 1.4-fold in Px compared with Ns (P < 0.05) but decreased 1.4-fold compared with Kx (P < 0.05). Fasting and postprandial proinsulin-to-C-peptide molar ratios were inappropriately increased in Px compared with Kx and Ns. Basal hepatic glucose production was increased 43% in Px and 33% in Kx compared with Ns (P < 0.05). Postprandial total systemic glucose appearance was similar in all three groups, whereas peripheral glucose disposal was 15% reduced in Px (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)


2007 ◽  
Vol 34 (6) ◽  
pp. 916-925 ◽  
Author(s):  
M. L. Soto-Montenegro ◽  
J. J. Vaquero ◽  
C. Arango ◽  
G. Ricaurte ◽  
P. García-Barreno ◽  
...  

Endocrinology ◽  
2005 ◽  
Vol 146 (12) ◽  
pp. 5425-5432 ◽  
Author(s):  
Yan Ao ◽  
Natalie Toy ◽  
Moon K. Song ◽  
Vay Liang W. Go ◽  
Hong Yang

Insulin secretion is impaired in type 2 diabetes (T2D). The insulin and glucose responses to central autonomic activation induced by excitation of brain medullary TRH receptors were studied in T2D Goto-Kakizaki (GK) rats. Blood glucose levels in normally fed, pentobarbital-anesthetized GK and nondiabetic Wistar rats were 193 and 119 mg/100 ml in males and 214 and 131 mg/100 ml in females. Intracisternal injection (ic) of the stable TRH analog RX 77368 (10 ng) induced significantly higher insulin response in both genders of overnight-fasted GK rats compared with Wistar rats and slightly increased blood glucose in female Wistar rats but significantly decreased it from 193 to 145 mg/100 ml in female GK rats. RX 77368 (50 ng) ic induced markedly greater glucose and relatively weaker insulin responses in male GK rats than Wistar rats. Bilateral vagotomy blocked ic RX 77368-induced insulin secretion, whereas adrenalectomy abolished its hyperglycemic effect. In adrenalectomized male GK but not Wistar rats, ic RX 77368 (50 ng) dramatically increased serum insulin levels by 6.5-fold and decreased blood glucose levels from 154 to 98 mg/100 ml; these changes were prevented by vagotomy. GK rats had higher basal pancreatic insulin II mRNA levels but a lower response to ic RX 77368 (50 ng) compared with Wistar rats. These results indicate that central-vagal activation-induced insulin secretion is susceptible in T2D GK rats. However, the dominant sympathetic-adrenal response to medullary TRH plays a suppressing role on vagal-mediated insulin secretion. This unbalanced vago-sympathetic activation by medullary TRH may contribute to the impaired insulin secretion in T2D.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xishuai Wang ◽  
Zhiqing Wang ◽  
Donghui Tang

AbstractWe investigated the impact of aerobic exercise (AE) on multiple organ dysfunction syndrome (MODS), aortic injury, pathoglycemia, and death during sepsis. ICR mice were randomized into four groups: Control (Con), Lipopolysaccharide (LPS), Exercise (Ex), and Exercise + LPS (Ex + LPS) groups. Mice were trained with low-intensity for 4 weeks. LPS and Ex + LPS mice received 5 mg/kg LPS intraperitoneally for induction of sepsis. Histopathological micrographs showed the organ morphology and damage. This study examined the effects of AE on LPS-induced changes in systemic inflammation, pulmonary inflammation, lung permeability, and bronchoalveolar lavage fluid (BALF) cell count, oxidative stress-related indicators in the lung, blood glucose levels, plasma lactate levels, serum insulin levels, plasma high-mobility group box 1 (HMGB1) levels, glucose transporter 1 (Glut1) and HMGB1, silent information regulator 1 (Sirt-1), and nuclear factor erythroid 2-related factor 2 (Nrf-2) mRNA expression levels in lung tissue. AE improved sepsis-associated multiple organ dysfunction syndrome (MODS), aortic injury, hypoglycemia, and death. AE prominently decreased pulmonary inflammation, pulmonary edema, and modulated redox balance during sepsis. AE prominently decreased neutrophil content in organ. AE prominently downregulated CXCL-1, CXCL-8, IL-6, TNF-α, Glu1, and HMGB1 mRNA expression but activated IL-1RN, IL-10, Sirt-1, and Nrf-2 mRNA expression in the lung during sepsis. AE decreased the serum levels of lactate and HMGB1 but increased blood glucose levels and serum insulin levels during sepsis. A 4-week AE improves sepsis-associated MODS, aortic injury, pathoglycemia, and death. AE impairs LPS-induced lactate and HMGB1 release partly because AE increases serum insulin levels and decreases the levels of Glut1. AE is a novel therapeutic strategy for sepsis targeting aerobic glycolysis.


Medicina ◽  
2018 ◽  
Vol 54 (5) ◽  
pp. 77 ◽  
Author(s):  
Tzu-Rong Peng ◽  
Ta-Wei Wu ◽  
You-Chen Chao

Background: Gestational diabetes mellitus (GDM) is a condition, in which women develop high blood sugar levels during pregnancy without having diabetes. Evidence on the effects of probiotics on the blood glucose levels of women with GDM is inconsistent. Objective: The present study aimed to investigate the effects of probiotics on the blood glucose levels of pregnant women. Methods: Online databases, such as PubMed, Cochrane, and Excerpta Medica Database (EMBASE) were searched for randomized controlled trials (RCTs) published before July 2018. Trials had to meet the inclusion criteria of our study. Methodological quality and risk bias were independently assessed by two reviewers. Data were pooled using a random effects model and were expressed as the mean difference (MD) and 95% confidence interval (CI). Heterogeneity was evaluated and quantified as I2. Results: In total, 12 RCTs were included in this study. Studies have shown that the use of probiotics significantly reduced the fasting blood glucose (FBG) level (MD: −0.10 mmol/L; 95% CI: −0.19, −0.02), insulin concentration (MD: −2.24 μIU/mL; 95% CI: −3.69, −0.79), Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) score (MD: −0.47; 95% CI: −0.74, −0.21), and Homeostasis model of assessment-estimated β cell function (HOMA-B) score (MD: −20.23; 95% CI: −31.98, −8.49) of pregnant women. In a subgroup analysis, whether the blood glucose-lowering effect of probiotics influenced the diagnosis of pregnant women with GDM was assessed. The results showed that probiotics had significantly reduced the fasting blood glucose (FBG) level (MD: −0.10 mmol/L; 95% CI: −0.17, −0.04) and HOMA-IR score (MD: −0.37; 95% CI: −0.72, −0.02) of pregnant women who were not diagnosed with GDM. Conclusion: Probiotics reduce the blood glucose level of pregnant women, especially without GDM diagnosis. However, further research using RCTs must be conducted to validate the results of the present study.


Endocrine ◽  
2020 ◽  
Vol 70 (3) ◽  
pp. 629-634 ◽  
Author(s):  
Rossella Cannarella ◽  
Nicolò Musso ◽  
Rosita A. Condorelli ◽  
Marco Musmeci ◽  
Stefania Stefani ◽  
...  

Abstract Objective To assess the role of c. 2039 A/G (p. Asp680Ser) (rs6166) and c. −29 G/A (rs1394205) follicle-stimulating hormone receptor (FSHR) gene single nucleotide polymorphisms (SNPs) in a cohort of healthy men. Methods One-hundred twenty-seven healthy men underwent evaluation of the anthropometric parameters, assessment of metabolic and lipid profile, measurement FSH serum levels, and genotyping of both the aforementioned FSHR SNPs. Data grouped according to the FSHR rs6166 or rs1394205 genotypes underwent to statistical analysis. Main results The three groups of men for each FSHR SNP did not differ statistically significantly for body mass index and serum FSH levels. As for FSHR rs6166 SNP, glucose levels were significantly lower in men with the GG genotype compared with those with the AA genotype. Men with AG had lower insulin levels and HOMA index values compared with those carrying the genotype AA (p < 0.05). The GG group showed a negative correlation between serum FSH levels and insulin and between serum FSH levels and HOMA index (p < 0.05). In contrast, men grouped according to the FSHR rs1394205 genotype showed no significant difference in blood glucose, serum insulin levels, and HOMA index. The AG group showed a negative correlation between FSH insulin and between serum FSH levels and HOMA index (p < 0.05). Conclusions Men with the genotype GG of the FSHR rs6166 SNP have lower blood glucose levels than those with the AA genotype. Their FSH levels inversely correlated with insulin and HOMA index. In contrast, the genotype FSHR rs6166 A/G did not reveal any role of FSH on glucose metabolism in healthy men. The inverse relationship between FSH and insulin or HOMA index in the group with the genotype GG of the FSHR rs6166 SNP suggests a possible cross-talk between FSH and insulin.


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