Scaling vs. nonscaling methods of assessing autonomic tone in streptozotocin-induced diabetic rats

2002 ◽  
Vol 283 (3) ◽  
pp. H1142-H1149 ◽  
Author(s):  
Itay Perlstein ◽  
Nir Sapir ◽  
Joshua Backon ◽  
Dan Sapoznikov ◽  
Roman Karasik ◽  
...  
Keyword(s):  
Cross Correlation ◽  
Diabetic Rats ◽  
Fluctuation Analysis ◽  
Autoregressive Modeling ◽  
Autonomic Tone ◽  
Scaling Parameter ◽  
Average Value ◽  
Disease States ◽  
Streptozotocin Induced Diabetes ◽  
Baseline Conditions

We studied heart rate variability in rats by power scaling spectral analysis (PSSA), autoregressive modeling (AR), and detrended fluctuation analysis (DFA), assessed stability by coefficient of variation between consecutive 6-h epochs, and then compared cross-correlation among techniques. These same parameters were checked from baseline conditions through acute and chronic disease states (streptozotocin-induced diabetes) followed by therapeutic intervention (insulin). Cross-correlation between methods over the entire time period was r = 0.94 (DFA and PSSA), r = 0.81 (DFA and AR), and r = 0.77 (AR and PSSA). Under baseline conditions the scaling parameter measured by DFA and PSSA and the high-frequency (HF) component measured by AR fluctuated around an average value, but these fluctuations were different for the three methods. After diabetes induction, a strong correlation was found between the HF power and the short-term scaling parameter. Despite their differences in methodology, DFA and PSSA assess changes in parasympathetic tone as detected by autoregressive modeling.

Vasopressin V1 and V2 receptors in diabetes mellitus

1994 ◽  
Vol 266 (2) ◽  
pp. E217-E223 ◽  
Author(s):  
D. Trinder ◽  
P. A. Phillips ◽  
J. M. Stephenson ◽  
J. Risvanis ◽  
A. Aminian ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Inositol Phosphate ◽  
Free Water ◽  
Diabetic Rats ◽  
Biological Responses ◽  
Liver And Kidney ◽  
Streptozotocin Induced Diabetes ◽  
V2 Receptor ◽  
Plasma Arginine ◽  
Long Acting

Diabetes mellitus causes hypertonicity, increased plasma arginine vasopressin (AVP), polydipsia, and polyuria. Downregulation of AVP V2 receptors may contribute to the polyuria through diminished V2 receptor-mediated free water retention. After 2 wk of streptozotocin-induced diabetes mellitus, the diabetic rats had raised plasma glucose, AVP, and osmolality levels (P < 0.001) compared with nondiabetic controls (Sham). Insulin treatment (4 U long-acting insulin sc, daily) partially lowered these values (P < 0.01). There was a reduction in the number of renal and hepatic V1 receptors in the diabetic and diabetic+insulin animals compared with the sham animals (P < 0.05). The receptor affinity remained unchanged. In parallel, there was a reduction in maximum AVP-activated total inositol phosphate production in the liver and kidney of the diabetic and diabetic+insulin animals compared with the sham animals (P < 0.05). The density and affinity of renal V2 receptors and AVP-stimulated adenosine 3',5'-cyclic monophosphate production in the diabetic and diabetic+insulin animals were unchanged compared with the sham. These results demonstrate differential regulation of AVP receptors and suggest that downregulation of renal V2 receptors does not contribute to the polyuria of diabetes. In contrast, downregulation of V1 receptors might contribute to diminished V1 receptor-mediated biological responses to AVP seen in diabetes mellitus.

scholarly journals The acute effects of different spironolactone doses on cardiac function in streptozotocin-induced diabetic rats

2017 ◽  
Vol 95 (11) ◽  
pp. 1343-1350
Author(s):  
Aleksandra Vranic ◽  
Stefan Simovic ◽  
Petar Ristic ◽  
Tamara Nikolic ◽  
Isidora Stojic ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Systolic Function ◽  
Diabetic Rats ◽  
Diabetic Rat ◽  
Albino Rats ◽  
Acute Administration ◽  
Rat Hearts ◽  
Patients With Diabetes ◽  
Streptozotocin Induced Diabetes ◽  
Wistar Albino Rats

Currently, cardiovascular diseases are the leading cause of global mortality, while diabetes mellitus remains an important cause of cardiovascular morbidity. A recent study showed that patients with diabetes mellitus treated with mineralocorticoid receptor antagonists have improved coronary microvascular function, leading to improved diastolic dysfunction. In this study, we evaluated the influence of acute administration of spironolactone on myocardial function in rats with streptozotocin-induced diabetes mellitus, with special emphasis on cardiodynamic parameters in diabetic rat hearts. The present study was carried out on 40 adult male Wistar albino rats (8 weeks old). Rats were randomly divided into 4 groups (10 animals per group): healthy rats treated with 0.1 μmol/L of spironolactone, diabetic rats treated with 0.1 μmol/L of spironolactone, healthy rats treated with 3 μmol/L of spironolactone, and diabetic rats treated with 3 μmol/L of spironolactone. Different, dose-dependent, acute responses of spironolactone treatment on isolated, working diabetic and healthy rat heart were observed in our study. In healthy rats, better systolic function was achieved with higher spironolactone dose, while in diabetic rats, similar effects of low and high spironolactone dose were observed.

scholarly journals Assessment of anti-diabetic activity of alcoholic and hydro-alcoholic extract of Terminalia arjuna & Syzygium cumini in streptozotocin-induced diabetes in Wistar rats

2020 ◽  
Vol 11 (SPL4) ◽  
pp. 1870-1882
Author(s):  
Takru Harshit ◽  
Dixit Praveen K ◽  
Kumar Kapil ◽  
Nagarajan K
Keyword(s):  
Body Weight ◽  
Glucose Level ◽  
Biochemical Parameters ◽  
Wistar Rats ◽  
Diabetic Rats ◽  
Terminalia Arjuna ◽  
Alcoholic Extract ◽  
Syzygium Cumini ◽  
Liver And Pancreas ◽  
Streptozotocin Induced Diabetes

We aimed to evaluate the effect of anti-diabetic activity of Terminalia arjuna, and Syzygium cumini extracts in Streptozotocin (STZ) induced diabetes in Wistar rats. STZ (55mg/kg) followed by nicotinamide (100mg/kg) was given to rats by intraperitoneal route to induce diabetes. Oral administration of alcoholic and hydro-alcoholic extracts of T. arjuna (TAAE) (250mg/kg and 500mg/kg), S. cumini (SCAE) (200mg/kg and 400mg/kg) and their composite extract were given to rats along with standard anti-diabetic drug Glibenclamide (5mg/kg). We evaluated body weight, glucose level, lipid profile and biochemical parameters in STZ induced diabetic rats. Also, histopathological studied were done in liver, kidney and pancreatic tissues of rats. Our finding revealed that TAAE and TAHE at 250mg/kg b.w. and 500mg/kg b.w., SCAE and SCHE at 400mg/kg b.w. and combination of TAAE (250mg/kg b.w.)+SCAE (400mg/kg b.w.) had a positive effect in lowering the blood glucose level and body weight on 28th day as compared to the initial observation on 0th day and also restored all the biochemical parameters such as LDL, VLDL, triglycerides and total Cholesterol and HDL towards the normal levels as well as histopathological improvement in Kidney, Liver and Pancreas. Data analysis showed that composite extract of TAAE (250mg/kg) and SCAE (400mg/kg ) improved diabetic consequences more effectively than composite extract of TAHE (500mg/kg) and SCHE (400mg/kg). TAAE and SCHE, in combination, demonstrate as a potential therapeutic agent against diabetes.

scholarly journals Hypoglycemic Potential of Dietary Supplementation of Protein Isolate from Fermented Cucumeropsis manii in Streptozotocin Induced Hyperglycemic in Male Wistar Albino Rats

2021 ◽  
pp. 31-42
Author(s):  
A. O. Abiola ◽  
A. O. Iyoribhe ◽  
S. A. Adeniyi ◽  
O. B. Adu ◽  
A. S. Ogunbowale ◽  
...  
Keyword(s):  
Blood Glucose ◽  
Blood Glucose Concentration ◽  
Diabetic Control ◽  
Protein Isolate ◽  
Diabetic Rats ◽  
Control Group ◽  
Albino Rats ◽  
Antioxidant Enzyme Activities ◽  
Cvd Risk ◽  
Streptozotocin Induced Diabetes

The effect of Protein isolate from fermented melon seeds (Ogiri Protei Isolates; OPI) of Cucumeropsis manii on blood glucose, lipid profile, and antioxidant enzyme activities in streptozotocin (STZ)-induced diabetic rats was investigated. Thirty Male Wistar rats were divided into five equal groups. GThe first control group with no exposure. The second group of rats with Streptozotocin-induced non-treated diabetes. The 3rd and 4th groups of rats with Streptozotocin-induced diabetes supplemented with Ogiri protein isolates (200, 600 mg/kg in diet). And the 5th group of rats with Streptozotocin-induced diabetes administered glibenclamide in a dose 500 ug/kg in diet [17]. The OPI was administered for 6 weeks. The administration of OPI reduced the blood glucose concentration of the STZ-induced diabetic rats. Sera and hepatic superoxide dismutase, activities of the STZ-induced diabetic rats were significantly (P< 0.05) increased in comparison with the diabetic control rats. Lipid peroxidation of the supplemented OPI diabetic rats was significantly (P< 0.05) decreased in comparison with the diabetic control rats as the administration of OPI to the STZ-induced diabetic rats significantly increased the enzymes’ activities. The concentration of low-density lipoproteins in the OPI supplemented rats was significantly elevated. These data demonstrate that OPI supplements might be beneficial for correcting hyperglycemia but the consumption of OPI can modulate some tissue lipids in a direction not beneficial for CVD risk in patients with diabetes.

Food intake and gastric emptying in rats with streptozotocin-induced diabetes

1984 ◽  
Vol 247 (6) ◽  
pp. R1054-R1061 ◽  
Author(s):  
J. G. Granneman ◽  
E. M. Stricker
Keyword(s):  
Gastric Emptying ◽  
Food Intake ◽  
Glucose Absorption ◽  
Diabetic Rats ◽  
High Carbohydrate Diet ◽  
Carbohydrate Diet ◽  
Low Carbohydrate Diet ◽  
High Carbohydrate ◽  
Low Carbohydrate ◽  
Streptozotocin Induced Diabetes

Recent studies suggest that the rate of nutrient transit through the upper gastrointestract may provide cues that are important to the control of food intake. We examined gastrointestinal function in rats with streptozotocin-induced diabetes and related these findings to concomitant changes in food intake. Control and diabetic rats were adapted to one of two isocaloric diets either high in carbohydrate or fat. Control rats ate similar amounts of each diet. In contrast, diabetic animals fed high-carbohydrate diet were hyperphagic, whereas those fed low-carbohydrate diet ate normal amounts of food. Gastric emptying, intestinal mass, disaccharidase activity, and glucose absorption were increased in normophagic diabetic rats fed a low-carbohydrate diet. Feeding diabetic rats high-carbohydrate diet potentiated each of these effects, and food intake was highly correlated with rate of gastric emptying. These and other results indicate that diabetes enhances gastric emptying and intestinal carbohydrate digestion and absorption, even in the absence of hyperphagia. Consequently, the hyperphagia of diabetic rats may be in part a behavioral response to a greatly accelerated clearance of nutrients from the upper gastrointestinal tract that occurs when these animals are fed diets rich in carbohydrate.

scholarly journals BOLD MRI to evaluate early development of renal injury in a rat model of diabetes

2018 ◽  
Vol 46 (4) ◽  
pp. 1391-1403 ◽  
Author(s):  
Qidong Wang ◽  
Chuangen Guo ◽  
Lan Zhang ◽  
Rui Zhang ◽  
Zhaoming Wang ◽  
...  
Keyword(s):  
Renal Injury ◽  
Diabetic Rats ◽  
Blood Oxygenation ◽  
Dynamic Changes ◽  
Bold Mri ◽  
Oxygenation Level ◽  
Mri Scans ◽  
Streptozotocin Induced Diabetes ◽  
Magnetic Resonance Imaging Mri ◽  
Diabetes Induction

Objective To investigate changes in renal oxygenation levels by blood-oxygenation-level dependent (BOLD)-magnetic resonance imaging (MRI), and to evaluate BOLD-MRI for detecting early diabetic renal injury. Methods Seventy-five rats, with unilateral nephrectomy, were randomly divided into streptozotocin-induced diabetes mellitus (DM, n = 65) and normal control (NC, n = 10) groups. BOLD-MRI scans were performed at baseline (both groups) and at 3, 7, 14, 21, 28, 35, 42, 49, 56, 63 and 70 days (DM only). Renal cortical (C) and medullary (M) R2* signals were measured and R2* medulla/cortex ratio (MCR) was calculated. Results DM-group CR2* and MR2* values were significantly higher than NC values following diabetes induction. R2* values increased gradually and peaked at day 35 (CR2*, 33.95 ± 0.34 s–1; MR2*, 43.79 ± 1.46 s–1), then dropped gradually (CR2*, 33.17 ± 0.69 s–1; MR2*, 41.61 ± 0.95 s–1 at day 70). DM-group MCR rose gradually from 1.12 to 1.32 at day 42, then decreased to 1.25 by day 70. Conclusions BOLD-MRI can be used to non-invasively evaluate renal hypoxia and early diabetic renal injury in diabetic rats. MCR may be adopted to reflect dynamic changes in renal hypoxia.

scholarly journals Comparison of the Effects of Glibenclamide on Metabolic Parameters, GLUT1 Expression, and Liver Injury in Rats With Severe and Mild Streptozotocin-Induced Diabetes Mellitus

Medicina ◽  
2012 ◽  
Vol 48 (10) ◽  
pp. 78 ◽  
Author(s):  
Jelizaveta Sokolovska ◽  
Sergejs Isajevs ◽  
Olga Sugoka ◽  
Jelena Sharipova ◽  
Natalia Paramonova ◽  
...  
Keyword(s):  
Gene Expression ◽  
Diabetes Mellitus ◽  
Protein Expression ◽  
Diabetic Rats ◽  
Metabolic Parameters ◽  
Gene And Protein Expression ◽  
Glut1 Expression ◽  
Mild Diabetes ◽  
Streptozotocin Induced Diabetes ◽  
Glut1 Gene

Background and Objective. Glucose transport via GLUT1 protein could be one of additional mechanisms of the antidiabetic action of sulfonylureas. Here, the GLUT1 gene and the protein expression was studied in rats in the course of severe and mild streptozotocin-induced diabetes mellitus and under glibenclamide treatment. Material and Methods. Severe and mild diabetes mellitus was induced using different streptozotocin doses and standard or high fat chow. Rats were treated with glibenclamide (2 mg/kg daily, per os for 6 weeks). The therapeutic effect of glibenclamide was monitored by measuring several metabolic parameters. The GLUT1 mRNA and the protein expression in the kidneys, heart, and liver was studied by means of real-time R T-PCR and immunohistochemistry. Results. The glibenclamide treatment decreased the blood glucose concentration and increased the insulin level in both models of severe and mild diabetes mellitus. Severe diabetes mellitus provoked an increase in both GLUT1 gene and protein expression in the kidneys and the heart, which was nearly normalized by glibenclamide. In the kidneys of mildly diabetic rats, an increase in the GLUT1 gene expression was neither confirmed on the protein level nor influenced by the glibenclamide treatment. In the liver of severely diabetic rats, the heart and the liver of mildly diabetic rats, the GLUT1 gene and the protein expression was changed independently of each other, which might be explained by abortive transcription, and pre- and posttranslational modifications of gene expression. Conclusions. The GLUT1 expression was found to be affected by the glucose and insulin levels and can be modulated by glibenclamide in severely and mildly diabetic rats. Glibenclamide can prevent the liver damage caused by severe hyperglycemia.

scholarly journals Long-Range Behaviour and Correlation in DFA and DCCA Analysis of Cryptocurrencies

2019 ◽  
Vol 7 (3) ◽  
pp. 51 ◽  
Author(s):  
Natália Costa ◽  
César Silva ◽  
Paulo Ferreira
Keyword(s):  
Time Scales ◽  
Cross Correlation ◽  
Data Availability ◽  
Fluctuation Analysis ◽  
Financial Assets ◽  
Sliding Windows ◽  
Cross Correlation Analysis ◽  
Short Time ◽  
Detrended Fluctuation ◽  
Great Development

In recent years, increasing attention has been devoted to cryptocurrencies, owing to their great development and valorization. In this study, we propose to analyse four of the major cryptocurrencies, based on their market capitalization and data availability: Bitcoin, Ethereum, Ripple, and Litecoin. We apply detrended fluctuation analysis (the regular one and with a sliding windows approach) and detrended cross-correlation analysis and the respective correlation coefficient. We find that Bitcoin and Ripple seem to behave as efficient financial assets, while Ethereum and Litecoin present some evidence of persistence. When correlating Bitcoin with the other cryptocurrencies under analysis, we find that for short time scales, all the cryptocurrencies have statistically significant correlations with Bitcoin, although Ripple has the highest correlations. For higher time scales, Ripple is the only cryptocurrency with significant correlation.

scholarly journals Cold and Dense Plasma Sheet Caused by Solar Wind Entry: Direct Evidence

Atmosphere ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 831
Author(s):  
Yue Yu ◽  
Zuzheng Chen ◽  
Fang Chen
Keyword(s):  
Solar Wind ◽  
Plasma Sheet ◽  
Cross Correlation ◽  
Direct Evidence ◽  
Dense Plasma ◽  
Ion Density ◽  
Average Value ◽  
Magnetospheric Multiscale ◽  
Cross Correlation Analysis ◽  
Solar Wind Entry

We present a coordinated observation with the Magnetospheric Multiscale (MMS) mission, located in the Earth’s magnetotail plasma sheet, and the Acceleration, Reconnection, Turbulence, and Electrodynamics of the Moon’s Interaction with the Sun (ARTEMIS) mission, located in the solar wind, in order to understand the formation mechanism of the cold and dense plasma sheet (CDPS). MMS detected two CDPSs composed of two ion populations with different energies, where the energy of the cold ion population is the same as that of the solar wind measured by ARTEMIS. This feature directly indicates that the CDPSs are caused by the solar wind entry. In addition, He+ was observed in the CDPSs. The plasma density in these two CDPSs are ~1.8 cm−3 and ~10 cm−3, respectively, roughly 4–30 times the average value of a plasma sheet. We performed a cross-correlation analysis on the ion density of the CDPS and the solar wind, and we found that it takes 3.7–5.9 h for the solar wind to enter the plasma sheet. Such a coordinated observation confirms the previous speculation based on single-spacecraft measurements.

scholarly journals Multifractal Analysis of Market Efficiency across Structural Breaks: Implications for the Adaptive Market Hypothesis

2020 ◽  
Vol 13 (10) ◽  
pp. 248
Author(s):  
Ashok Chanabasangouda Patil ◽  
Shailesh Rastogi
Keyword(s):  
Long Memory ◽  
Cross Correlation ◽  
Structural Breaks ◽  
Primary Objective ◽  
Fluctuation Analysis ◽  
Multifractal Detrended Fluctuation Analysis ◽  
Price Series ◽  
Cross Correlation Analysis ◽  
Large Fluctuations ◽  
Secondary Objective

The primary objective of this paper is to assess the behavior of long memory in price, volume, and price-volume cross-correlation series across structural breaks. The secondary objective is to find the appropriate structural breaks in the price series. The structural breaks in the series are identified using the Bai and Perron procedure, and in each segment, Multifractal Detrended Fluctuation Analysis (MFDFA) and Multifractal Detrended Cross-Correlation Analysis (MFDCCA) are conducted to capture the long memory in each series. The price series is persistent in small fluctuations and anti-persistent in large fluctuations across all the structural segments. This confirms that long memory in the series is not affected by the structural breaks. Both volume and price-volume cross-correlation are anti-persistent in all the structural segments. In other words, volume acts as a carrier of the information only in the non-volatile (normal) market. The varying Hurst exponent across the structural segments indicates the varying levels of persistence and signifies the volatile market. The findings of the study are useful for understanding the practical implications of the Adaptive Market Hypothesis (AMH).

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