Oral administration of SR-110, a peroxynitrite decomposing catalyst, enhances glucose homeostasis, insulin signaling, and islet architecture in B6D2F1 mice fed a high fat diet

Johns, Michael; Abadi, Sakineh Esmaeili Mohsen; Malik, Nehal; Lee, Joshua; Neumann, William L.; Rausaria, Smita; Imani-Nejad, Maryam; McPherson, Timothy; Schober, Joseph; Kwon, Guim

doi:10.1016/j.abb.2016.03.002

Cited by 2 publications

(5 citation statements)

References 33 publications

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“…Figure 5B shows the summary of % β-cell area obtained from lean (n ¼ 12) and HFD-fed mice (n ¼ 21). Increased islet size and number in HFD- fed mice have been extensively studied previously [32,33,34]. Moreover, HFD altered not only the architecture of islets but also percent α-cells [34].…”

Section: Resultsmentioning

confidence: 98%

“…Increased islet size and number in HFD- fed mice have been extensively studied previously [32,33,34]. Moreover, HFD altered not only the architecture of islets but also percent α-cells [34]. Normal healthy rodent islets contain β-cells in the center and α-cells in the periphery of the islet [32,33,34].…”

Section: Resultsmentioning

confidence: 99%

“…Moreover, HFD altered not only the architecture of islets but also percent α-cells [34]. Normal healthy rodent islets contain β-cells in the center and α-cells in the periphery of the islet [32,33,34]. HFD caused α-cells to migrate towards the center of the islet.…”

Section: Resultsmentioning

confidence: 99%

“…The similar changes of k 2 and k 4 support the impact of obesity on insulin-sensitive tissues as a whole. Although it is only at one time point (4 months after the respective diets), we have studied alterations in insulin signaling by examining the ratio of P-Akt/total Akt in the liver, heart, and skeletal muscle tissues isolated from lean-and HFD-fed mice injected with 0.65 U/kg insulin 5 min prior to asphyxiation by CO 2 [34]. All three tissues isolated from HFD-fed mice showed lower levels of p-Akt as compared to those from lean diet-fed mice [34], suggesting insulin resistance had developed in these tissues, corroborating low values of k 2 and k 4 found in the current study.…”

Section: Resultsmentioning

confidence: 99%

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Tracking changes of the parameters of glucose-insulin homeostasis during the course of obesity in B6D2F1 mice

Abadi

Balouchzadeh

Uzun

et al. 2020

Heliyon

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Obesity is one of the primary causes of type 2 diabetes mellitus (T2DM). To better understand how obesity impairs glucose-insulin homeostasis, we tracked fasting blood glucose and insulin levels and the key components of glucose-insulin homeostasis for 7 months in high fat diet (HFD; 45% fat) fed mice (n ¼ 8). Every 2 weeks we measured body weight, fasting blood glucose and insulin levels, and estimated 5 key rate constants of glucoseinsulin homeostasis using the methods established previously (Heliyon 3: e00310, 2017). Mice gained weight steadily, more than doubling their weights after 7 months (23.6 AE 0.5 to 52.3 AE 1.4 g). Fasting (basal) insulin levels were elevated (221.3 AE 16.7 to 1043.1 AE 90.5 pmol l -1 ) but fasting blood glucose levels unexpectedly returned to the baseline levels (152.8 AE 7.0 to 152.0 AE 7.2 mg/dl) despite significantly elevated levels (216.8 AE 44.9 mg/dl, average of 3 highest values for 8 mice) during the experimental period. After 7 months of HFD feeding, the rate constants for insulin secretion (k 1 ), insulin-independent glucose uptake (k 3 ), and insulin concentration where liver switches from glucose uptake to release (I pi ) were significantly elevated. Insulin-dependent glucose uptake (k 2 ) and rate constant of liver glucose transfer (k 4 ) were lowered but no statistical significance was reached. The novel and key finding of this study is the wide range of fluctuations of the rate constants during the course of obesity, reflecting the body's compensatory responses against metabolic alterations caused by obesity.

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Section: Resultsmentioning

confidence: 98%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

See 2 more Smart Citations

Tracking changes of the parameters of glucose-insulin homeostasis during the course of obesity in B6D2F1 mice

Abadi

Balouchzadeh

Uzun

et al. 2020

Heliyon

Self Cite

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show abstract

“…In healthy subjects, the liver processes large quantities of lipids, but stores only small amounts in the form of TAG, with steady state TAG contents of less than 5% [25]. Excess TAG accumulation in the liver occurs in the setting of obesity, insulin resistance, and type 2 diabetes [26,27]. In streptozotocin-induced diabetic rats, a consistent increase in hepatic TAG content was observed only in the ketotic diabetic rats with no insulin treatment [28].…”

Section: Plos Onementioning

confidence: 99%

Study of blood glucose and insulin infusion rate in real-time in diabetic rats using an artificial pancreas system

et al. 2021

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Artificial pancreas system (APS) is an emerging new treatment for type 1 diabetes mellitus. The aim of this study was to develop a rat APS as a research tool and demonstrate its application. We established a rat APS using Medtronic Minimed Pump 722, Medtronic Enlite sensor, and the open artificial pancreas system as a controller. We tested different dilutions of Humalog (100 units/ml) in saline ranged from 1:3 to 1:20 and determined that 1:7 dilution works well for rats with ~500g bodyweight. Blood glucose levels (BGL) of diabetic rats fed with chow diet (58% carbohydrate) whose BGL was managed by the closed-loop APS for the total duration of 207h were in euglycemic range (70–180 mg/dl) for 94.5% of the time with 2.1% and 3.4% for hyperglycemia (>180mg/dl) and hypoglycemia (<70 mg/dl), respectively. Diabetic rats fed with Sucrose pellets (94.8% carbohydrate) for the experimental duration of 175h were in euglycemic range for 61% of the time with 35% and 4% for hyperglycemia and hypoglycemia, respectively. Heathy rats fed with chow diet showed almost a straight line of BGL ~ 95 mg/dl (average 94.8 mg/dl) during the entire experimental period (281h), which was minimally altered by food intake. In the healthy rats, feeding sucrose pellets caused greater range of BGL in high and low levels but still within euglycemic range (99.9%). Next, to study how healthy and diabetic rats handle supra-physiological concentrations of glucose, we intraperitoneally injected various amounts of 50% dextrose (2, 3, 4g/kg) and monitored BGL. Duration of hyperglycemia after injection of 50% dextrose at all three different concentrations was significantly greater for healthy rats than diabetic rats, suggesting that insulin infusion by APS was superior in reducing BGL as compared to natural insulin released from pancreatic β-cells. Ex vivo studies showed that islets isolated from diabetic rats were almost completely devoid of pancreatic β-cells but with intact α-cells as expected. Lipid droplet deposition in the liver of diabetic rats was significantly lower with higher levels of triacylglyceride in the blood as compared to those of healthy rats, suggesting lipid metabolism was altered in diabetic rats. However, glycogen storage in the liver determined by Periodic acid-Schiff staining was not altered in diabetic rats as compared to healthy rats. A rat APS may be used as a powerful tool not only to study alterations of glucose and insulin homeostasis in real-time caused by diet, exercise, hormones, or antidiabetic agents, but also to test mathematical and engineering models of blood glucose prediction or new algorithms for closed-loop APS.

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Oral administration of SR-110, a peroxynitrite decomposing catalyst, enhances glucose homeostasis, insulin signaling, and islet architecture in B6D2F1 mice fed a high fat diet

Cited by 2 publications

References 33 publications

Tracking changes of the parameters of glucose-insulin homeostasis during the course of obesity in B6D2F1 mice

Tracking changes of the parameters of glucose-insulin homeostasis during the course of obesity in B6D2F1 mice

Study of blood glucose and insulin infusion rate in real-time in diabetic rats using an artificial pancreas system

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