scholarly journals Bilateral renal cryodenervation decreases arterial pressure and improves insulin sensitivity in fructose-fed Sprague-Dawley rats

2018 ◽  
Vol 315 (3) ◽  
pp. R529-R538 ◽  
Author(s):  
Tyler Soncrant ◽  
Dragana Komnenov ◽  
William H. Beierwaltes ◽  
Haiping Chen ◽  
Min Wu ◽  
...  
Keyword(s):  
Insulin Sensitivity ◽  
Arterial Pressure ◽  
Plasma Renin ◽  
Sprague Dawley ◽  
High Salt Diet ◽  
Glucose Levels ◽  
Fructose Intake ◽  
Blood Glucose Levels ◽  
Sprague Dawley Rats ◽  
High Fructose

Consumption of food high in fructose is prevalent in modern diets. One week of moderately high fructose intake combined with high salt diet has been shown to increase blood pressure and failed to suppress plasma renin activity (PRA). We tested the hypothesis that the hypertension and high PRA are consequences of elevated renal sympathetic nerve activity (RSNA). In protocol 1, we assessed RSNA by telemetry in conscious Sprague-Dawley rats given 20% fructose or 20% glucose in drinking water on a 0.4% NaCl diet (NS) for 1 wk and then transitioned to a 4% NaCl diet (HS). After an additional week, mean arterial pressure (MAP) and RSNA increased significantly in fructose-fed but not glucose-fed HS rats. In protocol 2, fructose (Fruc)- or glucose (Glu)-fed rats on NS or HS diet for 3 wk underwent sham denervation (shamDNX) or bilateral renal denervation using cryoablation (cryoDNX). MAP was higher in Fruc-HS rats compared with Glu-NS, Glu-HS, or Fruc-NS rats and decreased after cryoDNX ( P < 0.01). MAP did not change in Fruc-HS shamDNX rats. Renal norepinephrine content decreased by 85% in cryoDNX ( P < 0.01 vs. shamDNX). PRA significantly decreased after cryoDNX in both Fruc-NS and Fruc-HS rats. Nonfasting blood glucose levels were similar among the four groups. Glucose-to-insulin ratio significantly increased in Fruc-HS cryoDNX rats, consistent with greater insulin sensitivity. Taken together, these studies show that renal sympathoexcitation is, at least in part, responsible for salt-dependent increases in MAP, increased PRA, and decreased insulin sensitivity in rats fed a moderately high fructose diet for as little as 3 wk.

134 The Effect of Adipose Derived Stromal Vascular Fraction on Stasis Zone in an Experimental Burn Model on Streptozocin – Induced Diabetic Rats

2021 ◽  
Vol 42 (Supplement_1) ◽  
pp. S89-S90
Author(s):  
Cagri A Uysal ◽  
Burak Ozkan ◽  
Abbas Najimaldin Muhsun Al Bayati ◽  
Gonca Ozgun ◽  
Kadri Akinci ◽  
...  
Keyword(s):  
Blood Glucose ◽  
Cell Density ◽  
Inflammatory Cell ◽  
Burn Injury ◽  
Stromal Vascular Fraction ◽  
Vascular Density ◽  
Sprague Dawley ◽  
Glucose Levels ◽  
Blood Glucose Levels ◽  
Sprague Dawley Rats

Abstract Introduction Stasis zone is the encircling area of the coagulation zone which is a critical area determining the depth and width of the necrosis in burn patients. In our study we aim to salvage the stasis zone by injecting adipose derived stromal vascular fraction (ADSVF). Methods Intraperitoneal Streptozotocin was administered for the induction of diabetes mellitus (DM) and the development of DM was confirmed by the measurement of blood glucose levels in the blood samples with blood glucometer weekly 48 hours after injection. Rats with blood glucose levels above 200 mg/dl were accepted as diabetic. The diabetic animals were followed for 4 weeks before the intervention. Thermal injury was applied on dorsum of diabetic Sprague – Dawley rats (n=20) according to the previously described ‘‘comb burn’’ model. After the burn injury (30 minutes) on Sprague - Dawley rats; rat dorsum was separated into 2 equal parts consisting of 4 burn zones (3 stasis zone) on each pair. ADSVF cells harvested from inguinal fat pads of diabetic Sprague - Dawley rats (n=5) were injected on the right side while same amount of phosphate buffered saline (PBS) injected on the left side of the same animal. One week later, average vital tissue on the statis zone was determined by macroscopy, angiography and microscopy. Vascular density, inflammatory cell density and gradient of fibrosis were determined via immunohistochemical assay. Results Macroscopic stasis zone tissue survivability percentage (32 ± 3.28 %, 57 ± 4.28 %), average number of vessels (10.28 ± 1.28, 19.43 ± 1.72), capillary count (15.67 ± 1.97, 25.35 ± 2.15) and vascular density (1.55 ± 0.38, 2.14 ± 0.45) were higher on ADSVF side. Fibrosis gradient (1.87 ± 0.51, 1.50 ± 0.43) and inflammatory cell density (1.33 ± 0.40, 1.20 ± 0.32) were higher on the PBS side. Conclusions Macroscopic and microscopic findings determined that ADSVF has a statistically significant benefit for salvaging stasis zone on acute burn injuries in DM.

Juxtamedullary microvascular dysfunction during the hyperfiltration stage of diabetes mellitus

1994 ◽  
Vol 267 (1) ◽  
pp. F99-F105 ◽  
Author(s):  
K. Ohishi ◽  
M. I. Okwueze ◽  
R. C. Vari ◽  
P. K. Carmines
Keyword(s):  
Diabetes Mellitus ◽  
Microvascular Dysfunction ◽  
Sprague Dawley ◽  
Glucose Levels ◽  
Blood Glucose Levels ◽  
Sprague Dawley Rats ◽  
Vasoconstrictor Response ◽  
Wide Range ◽  
Single Nephron

This study was designed to identify and localize defects in renal microvascular function during the hyperfiltration stage of diabetes mellitus. Male Sprague-Dawley rats were injected intravenously with 65 mg/kg streptozotocin (IDDM rats) or vehicle (sham rats). IDDM rats received insulin (3 U.kg-1.day-1) via an osmotic minipump; sham rats received diluent. During the ensuing 2-wk period, blood glucose levels averaged 89 +/- 2 mg/dl in 33 sham rats and 290 +/- 13 mg/dl in 37 IDDM rats. At the end of this period, inulin clearance was elevated in eight IDDM rats (1.43 +/- 0.17 ml.min-1.g kidney wt-1) compared with six sham rats (0.78 +/- 0.05 ml.min-1.g kidney wt-1). The remaining animals served as tissue donors for study of the renal microvasculature using the in vitro blood-perfused juxtamedullary nephron technique. Kidneys from sham and IDDM rats were perfused with homologous blood at a renal arterial pressure of 110 mmHg. Juxtamedullary single-nephron glomerular filtration rate was higher in IDDM rats (41.5 +/- 5.4 nl/min) than in sham rats (25.4 +/- 2.4 nl/min). Afferent arteriolar inside diameter was greater in IDDM rats (34 +/- 2 microns) than in sham rats (22 +/- 1 microns); however, efferent arteriolar diameter did not differ between groups. The afferent arteriolar vasoconstrictor response to norepinephrine (NE) was attenuated in IDDM rats, relative to sham rats, over a wide range of NE concentrations. In contrast, NE evoked similar degrees of efferent vasoconstriction in IDDM and sham rats.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Anti-diabetic effects of aqueous extract of Dendropanax morbifera Lev. leaves in streptozotocin-induced diabetic Sprague-Dawley rats

2021 ◽  
Vol 61 (4) ◽  
pp. e38
Author(s):  
Min-Jae Kim ◽  
Ye-Jin Kang ◽  
Dong-Eon Lee ◽  
Suk Kim ◽  
Se-Hun Lim ◽  
...  
Keyword(s):  
Diabetic Control ◽  
Diabetic Rats ◽  
Sprague Dawley ◽  
Glucose Levels ◽  
Blood Biochemical ◽  
Blood Glucose Levels ◽  
Sd Rats ◽  
Sprague Dawley Rats ◽  
Dendropanax Morbifera ◽  
Treatment Of Diabetes

This study examined the anti-diabetic effects of aqueous extracts of Dendropanax morbifera leaves (DMWEs) in streptozotocin-induced diabetic Sprague-Dawley (SD) rats. Thirty male SD rats (body weight [BW], 250.4 ± 19.7 g) were divided into the following six groups: normal control rats (NC), diabetic control rats (DC), diabetic rats treated with metformin HCl 100 mg/kg BW (DT), diabetic rats treated with DMWEs 50 mg/kg BW (DM-50), diabetic rats treated with DMWEs 100 mg/kg BW (DM-100), and diabetic rats treated with DMWEs 200 mg/kg BW (DM-200). From two weeks of administration of DMWEs, the BW of all groups treated with DMWEs increased significantly compared to DC (p < 0.05). At four weeks after treatment, the blood glucose levels in DT, DM-100, and DM-200 decreased below 200 mg/dL, while the glycated hemoglobin concentrations in all groups administered DMWEs were similar to those of NC and DT. Regarding the blood biochemical parameters, the levels of aspartate transaminase, alanine transaminase, blood urea nitrogen, and creatinine in DM-100 and DM-200 were similar to those in NC and DT. Overall, these results highlight the effectiveness of DM-100 in the treatment of diabetes.

Effects of naloxone on renin and pressor responses to acute renal hypotension in rats.

1990 ◽  
Vol 259 (3) ◽  
pp. E432
Author(s):  
C J Weaver ◽  
M D Johnson
Keyword(s):  
Arterial Pressure ◽  
Abdominal Aorta ◽  
Pressor Response ◽  
Plasma Renin ◽  
Renal Perfusion ◽  
Opiate Antagonist ◽  
Sprague Dawley ◽  
Aortic Constriction ◽  
Sprague Dawley Rats ◽  
Pressor Responses

Reduction of renal perfusion is followed by increases in plasma renin activity (PRA) and arterial pressure. The present experiments were designed to determine if an opiate antagonist would alter pressor or renin responses to acute reduction of renal arterial pressure (RAP) in anesthetized rats. Male Sprague-Dawley rats were anesthetized with Inactin, and an adjustable constrictor device was placed around the abdominal aorta proximal to the renal arteries. One-half of the animals were pretreated with the opiate antagonist naloxone (2 mg/kg iv), and the other one-half were pretreated with saline vehicle. The abdominal aorta was then constricted to reduce RAP by 25% (measured as femoral arterial pressure) in one-half of the animals in each pretreatment group. Compared with vehicle pretreatment, naloxone pretreatment did not alter the PRA response to aortic constriction; however, naloxone did attenuate the pressor response. We conclude that 1) the PRA response to acute reduction of renal arterial pressure is not dependent on an opiate mechanism in the rat, and 2) attenuation of the pressor response to aortic constriction by naloxone in intact rats is not secondary to a suppression of the PRA response.

Area postrema: essential for support of arterial pressure after hemorrhage in rats

1990 ◽  
Vol 258 (6) ◽  
pp. R1472-R1478 ◽  
Author(s):  
K. M. Skoog ◽  
M. L. Blair ◽  
C. D. Sladek ◽  
W. M. Williams ◽  
M. L. Mangiapane
Keyword(s):  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Data Acquisition ◽  
Area Postrema ◽  
Plasma Renin ◽  
Base Line ◽  
Sprague Dawley ◽  
Time Period ◽  
Sprague Dawley Rats

Previous studies have indicated that the area postrema (AP) of the rat is necessary for the development of chronic angiotensin-dependent hypertension. The present study assesses the role of the AP in the maintenance of arterial pressure during hemorrhage. Sprague-Dawley rats were given sham or AP lesions 1 wk before the experiment. They were instrumented with femoral arterial and venous catheters 2 days before the experiment. On the day of the experiment, base-line mean arterial pressure (MAP) was measured for 1 h before hemorrhage. During the following 45 min, each rat was subjected to one 7-ml/kg hemorrhage every 15 min for a total of three hemorrhages. MAP was monitored by computerized data acquisition. As shown previously, MAP was slightly but significantly lower in AP-lesion rats compared with sham-lesion rats before the hemorrhage procedure. In AP-lesion rats, hemorrhage resulted in a significantly greater fall in arterial pressure than in sham-lesion rats. In spite of larger drops in pressure in AP-lesion rats, hemorrhage caused equivalent increases in plasma renin and vasopressin in both groups. In AP-lesion rats compared with sham-lesion rats, significant bradycardia was present before hemorrhage. Hemorrhage caused bradycardia in both sham- and AP-lesion rats relative to the prehemorrhage heart rates, but AP-lesion rats showed greater bradycardia than did sham-lesion rats during every time period. We conclude that the AP may play an important role in the defense of arterial pressure against hemorrhage.

Effect of Streptozotocin-Induced Diabetes on Estradiol-Stimulated Changes in the Ultrastructure of the Rat Endometrium

1981 ◽  
Vol 39 ◽  
pp. 532-533
Author(s):  
G.T. Frederick ◽  
R.M. Gardner ◽  
J.M. Kirkland ◽  
G.M. Stancel
Keyword(s):  
Electron Microscopic Examination ◽  
Sprague Dawley ◽  
Electron Microscopic ◽  
Thin Sections ◽  
Whole Cells ◽  
Glucose Levels ◽  
Blood Glucose Levels ◽  
Sprague Dawley Rats ◽  
Uterine Growth ◽  
Streptozotocin Induced Diabetes

Estradiol (E2)-stimulated uterine growth has been well characterized both biochemically and morphologically. Recent studies have shown that insulin plays an important role in the regulation of cellular development. This study examines the effect of streptozotocin-induced diabetes on E2-stimulated changes in the ultrastructure of the endometrium of the rat uterus.Sprague-Dawley rats were ovariectomized at 21 days of age. Diabetes, defined as blood glucose levels greater than 300mg%, was induced in half of these animals by the injection of 85mg streptozotocin/kg body weight.The remaining animals were classified as normal. Animals from both groups were injected with either 0.9% saline or 4μg E2/100gm body weight. At 18, 24, 36 and 48 hours post-injection of E2, uterine segments were collected from 8-10 animals in each experimental group and processed for electron microscopic examination. Uterine segments from saline-injected animals served as controls. Data summarized describe observations made from thin-sections and have not been extrapolated for whole cells.

scholarly journals The Isolation of Hypoglycaemic Compounds from Desmodium canum and Their Synergistic Effect on Blood Glucose Levels in Euglycaemic Sprague Dawley Rats

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Kemmoy Lattibeaudiere ◽  
Roy Porter ◽  
Ruby Lisa Alexander-Lindo
Keyword(s):  
Blood Glucose ◽  
Ethyl Acetate ◽  
Synergistic Effects ◽  
Significant Activity ◽  
Sprague Dawley ◽  
Entire Study ◽  
Glucose Levels ◽  
Blood Glucose Levels ◽  
Sprague Dawley Rats ◽  
Hypoglycaemic Activity

Desmodium canum (Strong back) commonly consumed as a tea or tonic is believed to possess hypoglycaemic activity. This paper sets out to isolate potential hypoglycaemic compounds present within the plant and investigate their synergistic effects on blood glucose levels in euglycaemic Sprague Dawley rats. The milled plant was sequentially extracted using hexane, ethyl acetate and methanol. The ethyl acetate extract was subjected to column chromatography yielding seven major fractions and were subsequently bioassayed using the Oral Glucose Tolerance Test (OGTT). Further chromatographic separation and analysis using Gas Chromatography–Mass Spectroscopy and Fourier Transform Infrared Spectroscopy enabled the identification of two hypoglycaemic compounds, oleic acid (OA) and succinic acid (SA). These were bioassayed individually and as a cocktail to determine the synergistic effects using OGTT. Intravenous administration of these compounds individually indicated both are very potent in retarding blood glucose levels. However, the most significant activity was observed on synergistic administration. The cocktail (1 : 1) displayed significant hypoglycaemic activity throughout the entire study. It also significantly differed from OA at the 120 min interval (3.43 ± 0.22 mmol/L vs. 4.98 ± 0.19 mmol/L, resp., p = 4.29 × 10 − 7 ) and significantly differed from SA at 30 min (3.95 ± 0.43 mmol/L vs. 5.17 ± 0.32 mmol/L, resp., p = 0.003 ), 90 min (4.35 ± 0.36 mmol/L vs. 5.49 ± 0.69 mmol/L, resp., p = 0.04 ), and 120 min intervals (3.43 ± 0.22 mmol/L vs. 4.94 ± 0.31, resp., p = 1.54 × 10 − 5 ). Oral administration of the cocktail showed comparable potency to that of metformin ( p > 0.05 ) throughout the OGTT curve. The synergistic effects of the naturally isolated compounds yielded higher potency levels than individual administration and when administered orally, the hypoglycaemic effect was similar to that of metformin. This may assist in paving a way to attempt a novel method in approaching antidiabetic therapy.

Reduced renal responses to volume expansion in streptozotocin-induced diabetic rats

1989 ◽  
Vol 257 (3) ◽  
pp. R672-R679 ◽  
Author(s):  
K. P. Patel ◽  
P. L. Zhang
Keyword(s):  
Volume Expansion ◽  
Diabetic Rats ◽  
Control Group ◽  
Sprague Dawley ◽  
Glucose Levels ◽  
Blood Glucose Levels ◽  
Sprague Dawley Rats ◽  
Before And After ◽  
Abnormal Volume ◽  
Group A

To determine whether the volume reflex is defective in the diabetic state, the diuretic and natriuretic responses to acute volume expansion (VE) were measured in streptozotocin (STZ)-induced diabetic (Dia) rats. Urine flow (UV) and sodium excretion (UNaV) were measured before and after VE from innervated and denervated kidneys in anesthetized (Inactin 0.1 g/kg, ip) control and Dia rats (Sprague-Dawley rats injected with vehicle or STZ 65 mg/kg ip, respectively, 2 wk before the experiment). Blood glucose levels were significantly elevated in the Dia group compared with the control group. A VE of 1.2 ml/min for 15 min produced a significantly greater diuresis and natriuresis in control rats compared with Dia rats. In addition, reducing the hyperglycemia in Dia rats (third group) by treatment with insulin reversed the blunted UV and UNaV responses to VE. Ratios of UV (innervated-denervated, I/D) before and after VE indicate significant increases in UV by the innervated kidneys, relative to the denervated kidneys in all three groups. I/D ratios of UNa V were not different between the three groups before VE, but were significantly smaller in the Dia rats compared with both control and STZ plus insulin groups after VE. This study demonstrates that 1) there is an abnormal volume reflex in the STZ-induced Dia rats; 2) the natriuresis due to renal sympatho-inhibition is blunted in response to VE in Dia rats; and 3) restoring the glucose levels to normal by insulin treatment in the Dia rats normalizes the volume reflex.

scholarly journals Fructose-induced leptin resistance exacerbates weight gain in response to subsequent high-fat feeding

2008 ◽  
Vol 295 (5) ◽  
pp. R1370-R1375 ◽  
Author(s):  
Alexandra Shapiro ◽  
Wei Mu ◽  
Carlos Roncal ◽  
Kit-Yan Cheng ◽  
Richard J. Johnson ◽  
...  
Keyword(s):  
Weight Gain ◽  
High Fat Diet ◽  
Leptin Resistance ◽  
Sprague Dawley ◽  
High Fat ◽  
Serum Leptin ◽  
Fructose Intake ◽  
Sprague Dawley Rats ◽  
High Fructose ◽  
Subsequent Exposure

It has been suggested that increased fructose intake is associated with obesity. We hypothesized that chronic fructose consumption causes leptin resistance, which subsequently may promote the development of obesity in response to a high-fat diet. Sprague-Dawley rats were fed a fructose-free control or 60% fructose diet for 6 mo and then tested for leptin resistance. Half of the rats in each group were then switched to high-fat diet for 2 wk, while the other half continued on their respective diets. Chronic fructose consumption caused leptin resistance, while serum leptin levels, weight, and adiposity were the same as in control rats that were leptin responsive. Intraperitoneal leptin injections reduced 24-h food intake in the fructose-free group (73.7 ± 6.3 vs. 58.1 ± 8 kcal, P = 0.02) but had no effect in fructose-fed rats (71.2 ± 6.6 vs. 72.4 ± 6.4 kcal, P = 0.9). Absence of anorexic response to intraperitoneal leptin injection was associated with 25.7% decrease in hypothalamic signal transducer and activator of transcription 3 phosphorylation in the high-fructose-fed rats compared with controls ( P = 0.015). Subsequent exposure of the fructose-mediated, leptin-resistant rats to a high-fat diet led to exacerbated weight gain (50.2 ± 2 g) compared with correspondingly fed leptin-responsive animals that were pretreated with the fructose-free diet (30.4 ± 5.8 g, P = 0.012). Our data indicate that chronic fructose consumption induces leptin resistance prior to body weight, adiposity, serum leptin, insulin, or glucose increases, and this fructose-induced leptin resistance accelerates high-fat induced obesity.

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