scholarly journals Effect of adrenal medullectomy on metabolic responses to chronic intermittent hypoxia in the frequently sampled intravenous glucose tolerance test

2017 ◽  
Vol 122 (4) ◽  
pp. 767-774 ◽  
Author(s):  
Mi-Kyung Shin ◽  
Woobum Han ◽  
Hoon Joo ◽  
Shannon Bevans-Fonti ◽  
Masakazu Shiota ◽  
...  
Keyword(s):  
Blood Glucose ◽  
Insulin Sensitivity ◽  
Glucose Metabolism ◽  
Intermittent Hypoxia ◽  
Fasting Glucose ◽  
Fasting Blood Glucose ◽  
Tolerance Test ◽  
Intravenous Glucose Tolerance Test ◽  
Intravenous Glucose ◽  
Insulin Levels

Obstructive sleep apnea is associated with type 2 diabetes. We have previously developed a mouse model of intermittent hypoxia (IH) mimicking oxyhemoglobin desaturations in patients with sleep apnea and have shown that IH increases fasting glucose, hepatic glucose output, and plasma catecholamines. We hypothesize that adrenal medulla modulates glucose responses to IH and that such responses can be prevented by adrenal medullectomy. We performed adrenal medullectomy or sham surgery in lean C57BL/6J mice, which were exposed to IH or intermittent air (control) for 4 wk followed by the frequently sampled intravenous glucose tolerance test (FSIVGTT) in unanesthetized unrestrained animals. IH was administered during the 12-h light phase (9 AM to 9 PM) by decreasing inspired oxygen from 21 to 6.5% 60 cycles/h. Insulin sensitivity (SI), insulin independent glucose disposal [glucose effectiveness (SG)], and the insulin response to glucose (AIRG) were determined using the minimal model method. In contrast to our previous data obtained in restrained mice, IH did not affect fasting blood glucose and plasma insulin levels in sham-operated mice. IH significantly decreased SG but did not affect SI and AIRG. Adrenal medullectomy decreased fasting blood glucose and plasma insulin levels and increased glycogen synthesis in the liver in hypoxic mice but did not have a significant effect on the FSIVGTT metrics. We conclude that, in the absence of restraints, IH has no effect on glucose metabolism in lean mice with exception of decreased SG, whereas adrenal medullectomy decreases fasting glucose and insulin levels in the IH environment. NEW & NOTEWORTHY To our knowledge, this is the first study examining the role of adrenal catecholamines in glucose metabolism during intermittent hypoxia (IH) in unanesthetized unrestrained C57BL/6J mice. We report that IH did not affect fasting glucose and insulin levels nor insulin sensitivity and insulin secretion during, whereas glucose effectiveness was decreased. Adrenal medullectomy decreased fasting blood glucose and insulin levels in mice exposed to IH but had no effect on glucose metabolism, insulin secretion, and insulin sensitivity.

Effects of Chuju Polysaccharides on Glucose Metabolism in Diabetic Mice

2021 ◽  
Vol 20 (1) ◽  
pp. 90-96
Author(s):  
Jian-ting Yang ◽  
Guo-liang Zhou ◽  
Min Wei ◽  
Yan Liu
Keyword(s):  
Superoxide Dismutase ◽  
Blood Glucose ◽  
Insulin Sensitivity ◽  
Glucose Metabolism ◽  
Glutathione Peroxidase ◽  
Fasting Glucose ◽  
Human Subjects ◽  
Fasting Blood Glucose ◽  
Diabetic Mice ◽  
Clinical Investigations

Chuju is a special Chinese flower tea with extensive health benefits. In this study, we have examined the effects of crude Chuju polysaccharides on alloxan-induced diabetic mice by measuring fasting blood glucose, insulin-related index, activities of superoxide dismutase, glutathione peroxidase, and content of malondialdehyde in the serum and liver. The results show that the treatment led to increased insulin sensitivity and decreased fasting glucose. The blood and liver levels of malondialdehyde decreased, whereas superoxide dismutase and glutathione peroxidase levels were elevated by crude Chuju polysaccharides in alloxan-induced diabetic mice. These data support a basis for clinical investigations on crude Chuju polysaccharides in diabetic human subjects.

Effects of obesity and ovarian steroids on insulin secretion and removal in sheep

1989 ◽  
Vol 256 (1) ◽  
pp. E116-E128 ◽  
Author(s):  
J. P. McCann ◽  
E. N. Bergman ◽  
T. J. Reimers
Keyword(s):  
Insulin Secretion ◽  
Glucose Metabolism ◽  
Plasma Concentrations ◽  
Tolerance Test ◽  
Intravenous Glucose Tolerance Test ◽  
Interactive Effects ◽  
Intravenous Glucose ◽  
Hepatic Glucose ◽  
Organ Removal ◽  
Glucose Output

The interactive effects of sex steroids and obesity on glucose metabolism and pancreatic secretion and organ removal of insulin were determined in multicatheterized lean and obese sheep by multiplying venoarterial concentration differences by plasma flows. Ovariectomized lean and dietary obese ewes received implants of progesterone and estradiol-17 beta that produced plasma concentrations of each equivalent to those during either anestrus (low progesterone), diestrus or pregnancy (high progesterone), or estrus (high estradiol). Sheep were exposed to each of the three steroid treatments for 2 days and fasted overnight before blood samples were collected for 5 h before (basal) and 90 min after injecting glucose (200 mg/kg) to simulate an intravenous glucose tolerance test (IVGTT). Regardless of steroid treatment, pancreatic secretory (18 vs. 5 mU/min) and hepatic (10 vs. 2 mU/min) and hindquarters (1.8 vs. 0.5 mU/min) removal rates of insulin in the basal state were greater (P less than 0.005) in obese than lean sheep. Obese sheep had greater (P less than 0.025) basal hepatic glucose output (66 vs. 47 mg/min) and similar hindquarters glucose removal (37 vs. 32 mg/min) as lean sheep even though arterial concentrations of insulin were fourfold higher (25 vs. 6 microU/ml; P less than 0.01) in the obese sheep. High progesterone increased (P less than 0.05) basal hepatic insulin removal in obese sheep. High progesterone and high estradiol increased insulin but decreased (P less than 0.05) glucose removal in hindquarters of obese sheep in the basal state. High progesterone potentiated significantly glucose-induced hyperinsulinemia in obese sheep, whereas high estradiol suppressed hepatic insulin removal but increased the removal of insulin by hindquarters during glucose stimulation in the obese sheep. We concluded that excessive insulin secretion, not decreased insulin removal, maintains the basal hyperinsulinemia in moderately obese sheep and that the progesterone-to-estradiol ratio has marked and divergent effects on insulin and glucose metabolism in individual tissues of sheep both in the basal state and during an IVGTT.

Modified protocols improve insulin sensitivity estimation using the minimal model

1987 ◽  
Vol 253 (6) ◽  
pp. E595-E602 ◽  
Author(s):  
Y. J. Yang ◽  
J. H. Youn ◽  
R. N. Bergman
Keyword(s):  
Standard Deviation ◽  
Insulin Sensitivity ◽  
Minimal Model ◽  
Insulin Response ◽  
Tolerance Test ◽  
Intravenous Glucose Tolerance Test ◽  
Improve Insulin Sensitivity ◽  
Intravenous Glucose ◽  
Sensitivity Estimation ◽  
Model Technique

We attempted to improve the precision of the estimation of insulin sensitivity (S1) from the minimal model technique by modifying insulin dynamics during a frequently sampled intravenous glucose tolerance test (FSIGT). Tolbutamide and somatostatin (SRIF) were used to change the insulin dynamics without directly affecting insulin sensitivity. Injection of tolbutamide (100 mg) at t = 20 min provoked an immediate secondary peak in insulin response, resulting in a greater integrated incremental insulin than the standard FSIGT. SRIF, injected at t = -1 min, delayed insulin secretion in proportion to the dose without any change in magnitude. Computer simulation was used to assess the precision of S1 estimation. Insulin dynamics from both standard and modified protocols were adjusted in magnitude, with the shape unchanged and analyzed to determine the effect of the magnitude of insulin response. Fractional standard deviation was reduced from 73% with the standard insulin profile to 23% with tolbutamide and 18% with the highest dose of SRIF. In addition, the fractional standard deviation of S1 estimates decreased exponentially with increasing magnitude of insulin response. Modified FSIGTs require a smaller insulin response than the standard protocol to achieve the same precision.

scholarly journals Interrelationships of growth hormone AluI polymorphism, insulinresistance, milk production and reproductive performance in Holstein-Friesian cos

2008 ◽  
Vol 53 (No. 11) ◽  
pp. 604-616 ◽  
Author(s):  
O. Balogh ◽  
O. Szepes ◽  
K. Kovacs ◽  
M. Kulcsar ◽  
J. Reiczigel ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Insulin Sensitivity ◽  
Glucose Tolerance Test ◽  
Area Under The Curve ◽  
Tolerance Test ◽  
Intravenous Glucose Tolerance Test ◽  
Intravenous Glucose ◽  
Intravenous Glucose Tolerance ◽  
Holstein Friesian ◽  
Friesian Cows

Healthy multiparous Holstein-Friesian cows (<I>n</I> = 22, parity: 2–4) from a large-scale dairy herd in Hungary were subjected to an intravenous glucose tolerance test 10–15 days after calving. <I>Alu</I>I genotype of growth hormone, several plasma metabolites and metabolic hormones were determined, and current and previous lactation yields were recorded. We also used the Revised Quantitative Insulin Sensitivity Check Index (RQUICKI) and its modified version (RQUICKI<sub>BHB</sub>) for the estimation of peripheral insulin sensitivity. The majority of cows (<I>n</I> = 18) was leucine homozygous (LL), four were heterozygous (LV) and there were no valine homozygous (VV) animals in the population. Current average milk production was not different between <I>Alu</I>I genotypes, but LV cows tended to have higher 305-day previous lactation yields (<I>P</I> = 0.13). <I>Alu</I>I polymorphism was not associated with any of the calculated glucose and leptin parameters of the intravenous glucose tolerance test (<I>P</I> > 0.58). Heterozygous cows were prone to higher basal insulin levels (<I>P</I> = 0.064), longer time to reach half of the maximal and basal insulin concentrations (<I>P</I> = 0.035 and <I>P</I> = 0.054, respectively) and larger insulin area under the curve (<I>P</I> = 0.032). Both RQUICKI and RQUICKIBHB estimated decreased insulin sensitivity in LV compared to LL cows (<I>P</I> = 0.055 and <I>P</I> = 0.044, respectively). Higher plasma NEFA and BHB levels accounted for slower glucose disappearance and lower insulin release and insulin clearance rate (<I>P</I> < 0.05). Average yield was inversely related to glucose area under the curve (<I>P</I> = 0.040) and time to reach baseline concentration (<I>P</I> = 0.005). Plasma cortisol lowered glucose clearance rate (<I>P</I> = 0.040) and prolonged time to reach basal levels (<I>P</I> = 0.006). More weight loss was associated with higher glucose peak and prolonged glucose disappearance time (<I>P</I> = 0.055 and <I>P</I> = 0.024, respectively). All cows became cyclic and showed signs of estrus during the study period. There were no differences between leucine homozygous and heterozygous animals in the onset of ovarian activity and in the time of first observed estrus (<I>P</I> > 0.540). We conclude that Holstein-Friesian cows heterozygous for <I>Alu</I>I polymorphism of the growth hormone gene may be more likely to develop insulin resistance during early lactation than leucine homozygous cows. Decreased insulin sensitivity could be part of a homeorhetic adaptation process that supports nutrient partioning for the use of the mammary gland and may allow LV cows to reach higher yields throughout lactation.

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