Dose-Dependent Effects of Endothelin-1 on Retinal and Optic Nerve Morphology in Sprague Dawley Rats

2019 ◽  
Vol 13 (1) ◽  
pp. 73-80 ◽  
Author(s):  
Natasha Najwa Nor Arfuzir ◽  
Renu Agarwal ◽  
Igor Iezhitsa ◽  
Puneet Agarwal ◽  
Nafeeza Mohd Ismail
Keyword(s):  
Optic Nerve ◽  
Sprague Dawley ◽  
Endothelin 1 ◽  
Sprague Dawley Rats ◽  
Dose Dependent

Glutamine promotes triglyceride absorption in a dose-dependent manner

2002 ◽  
Vol 282 (2) ◽  
pp. G317-G323 ◽  
Author(s):  
Jeffrey B. Schwimmer ◽  
Looi Ee ◽  
Shuqin Zheng ◽  
Patrick Tso
Keyword(s):  
Amino Acid ◽  
Amino Acid Mixture ◽  
Lipid Absorption ◽  
Acid Mixture ◽  
Dependent Manner ◽  
Sprague Dawley ◽  
Feeding Tubes ◽  
Mesenteric Lymph ◽  
Sprague Dawley Rats ◽  
Dose Dependent

Dietary proteins may play a role in lipid absorption. Whether amino acids are specifically involved is unknown. We hypothesized that enterally administered l-glutamine (l-Gln) given with a lipid meal increases triglyceride (TG) absorption in rats. Mesenteric lymph fistulae and gastroduodenal feeding tubes were placed in adult male Sprague-Dawley rats. The animals received an enteral bolus of Intralipid (5 ml) followed by enteral infusion of increasing concentrations of l-Gln in saline (0, 85, 170, or 340 mM) or equimolar concentrations of the inactive isomer d-Gln or an essential amino acid mixture without Gln. Lymph was collected continuously for 6 h and analyzed for TG content. Animals infused with 85 mM l-Gln had a 64% increase in total TG output vs. controls ( P < 0.05) despite no difference in lymph flow rate. Total TG output for animals infused with 340 mMl-Gln declined by 43% vs. controls ( P < 0.05). The effect of Gln in promoting lymphatic fat transport is specific to l-Gln and not shared by d-Gln or an equivalent amino acid mixture. l-Gln is capable of either promoting or impairing lymphatic TG transport in a dose-dependent manner.

Cinnamomum cassia ameliorates Ni-NPs-induced liver and kidney damage in male Sprague Dawley rats

2020 ◽  
Vol 39 (11) ◽  
pp. 1565-1581
Author(s):  
S Iqbal ◽  
F Jabeen ◽  
C Peng ◽  
MU Ijaz ◽  
AS Chaudhry
Keyword(s):  
Dependent Manner ◽  
Sprague Dawley ◽  
Cinnamomum Cassia ◽  
Preliminary Information ◽  
Sprague Dawley Rats ◽  
Liver And Kidney ◽  
Altered Blood ◽  
Biochemical Analyses ◽  
Dose Dependent ◽  
Different Doses

Nickel nanoparticles (Ni-NPs) have been widely used in various industries related to electronics, ceramics, textiles, and nanomedicine. Ambient and occupational exposure to Ni-NPs may bring about potential detrimental effects on animals and humans. Thus, there is a growing effort to identify compounds that can ameliorate NPs-associated pathophysiologies. The present study examined Cinnamomum cassia ( C. cassia) bark extracts (CMBE) for its ameliorative activity against Ni-NPs-induced pathophysiological and histopathological alterations in male Sprague Dawley rats. The biochemical analyses revealed that dosing rats with Ni-NPs at 10 mg/kg/body weight (b.w.) significantly altered the normal structural and biochemical adaptations in the liver and kidney. Conversely, supplementations with CMBE at different doses (225, 200, and 175 mg/kg/b.w. of rat) ameliorated the altered blood biochemistry and reduced the biomarkers of liver and kidney function considerably ( p < 0.05) in a dose-dependent manner. However, the best results were at 225 mg/kg/b.w. of rat. The study provided preliminary information about the protective effect of C. cassia against Ni-NPs indicated liver and kidney damages. Future investigations are needed to explore C. cassia mechanism of action and isolation of single constituents of C. cassia to assess their pharmaceutical importance accordingly.

scholarly journals Collagen-Induced Reduction in Rat Circulating Platelet Count: Influence of Platelet Function Inhibitors

1977 ◽  
Author(s):  
I.B. Holmes
Keyword(s):  
Platelet Count ◽  
Platelet Function ◽  
Test System ◽  
Collagen Fibrils ◽  
Dependent Manner ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Dose Dependent ◽  
Double Lumen Cannula ◽  
Antiinflammatory Compound

The effect on circulating platelet count of repeated intravenous infusions of collagen fibrils was measured in male OFA Sprague-Dawley rats (400-550 g). Citrated blood was pumped from the left carotid artery of anaesthetized animals, via a siliconized double-lumen cannula, into the manifold of a Technicon Autocounter, for continuous registration of platelet count. Native collagen fibrils (Collagenreagent ‘Horm’) were infused intravenously for 1 min at 15 min intervals. Successive increasing collagen doses (20-320 pg/kg) induced dose-dependent reduction in platelet count, measured as absolute platelet number disappearing from the circulation. Repeated infusion of collagen 160 pg/kg produced constant, partially reversible, reduction in platelet count. Several known inhibitors of platelet aggregation were investigated in the described test system. Collagen effects were inhibited in a dose-dependent manner to a maximum of 50-60 %, and drug activity was thus quantitated on the basis of dose producing 30 % inhibition (ID30): prostaglandin E1 (1.6 pg/kg/min i.v. infusion), SH-869 (1.1 mg/kg i.v.), aspirin (33.1 mg/kg p.o.), proquazone, a new non-steroidal antiinflammatory compound (5.0 mg/kg p.o.). That part of the collagen response not inhibited might be attributed to the initial phase of platelet adhesion to collagen, known to be relatively refractive to platelet function inhibitors.

Protective Effect of Reduced Glutathione against CIS-Dichlorodiammine Platinum (II)–Induced Nephrotoxicity and Lethal Toxicity

1983 ◽  
Vol 69 (2) ◽  
pp. 105-111 ◽  
Author(s):  
Franco Zunino ◽  
Odoardo Tofanetti ◽  
Adriana Besati ◽  
Ennio Cavalletti ◽  
Giuseppina Savi
Keyword(s):  
Reduced Glutathione ◽  
Body Weight Loss ◽  
Dependent Manner ◽  
Sprague Dawley ◽  
Antitumor Effects ◽  
Partial Protection ◽  
Lethal Toxicity ◽  
Sprague Dawley Rats ◽  
Serum Blood Urea Nitrogen ◽  
Dose Dependent

Pretreatment of Swiss mice and Sprague-Dawley rats with glutathione (GSH) reduced the acute lethal toxicity of cis-dichlorodiammine platinum (II) (cis-DDP) in a dose-dependent manner. The protection was accompanied by reduction of both body weight loss and by reduction of nephrotoxicity, as measured by a rise in serum blood urea nitrogen (BUN), creatinine levels and by histopathologic changes, which occurred 4 days following cis-DDP treatment. The antitumor effects of cis-DDP on experimental tumor models (P388 and Gross leukemia) were not significantly altered by GSH treatment. It is suggested that the partial protection by GSH from acute toxicity of the antitumor drug is directly related to protection of renal function.

17β-Estradiol modulates vasoconstriction induced by endothelin-1 following trauma-hemorrhage

2007 ◽  
Vol 292 (1) ◽  
pp. H245-H250 ◽  
Author(s):  
Zheng F. Ba ◽  
Ailing Lu ◽  
Tomoharu Shimizu ◽  
László Szalay ◽  
Martin G. Schwacha ◽  
...  
Keyword(s):  
Control Level ◽  
No Synthase ◽  
Sprague Dawley ◽  
Response Curves ◽  
Endothelin 1 ◽  
Sprague Dawley Rats ◽  
17Β Estradiol ◽  
Synthase Inhibitor

Although endothelin-1 (ET-1) induces vasoconstriction, it remains unknown whether 17β-estradiol (E2) treatment following trauma-hemorrhage alters these ET-1-induced vasoconstrictive effects. In addition, the role of the specific estrogen receptor (ER) subtypes (ER-α and ER-β) and the endothelium-localized downstream mechanisms of actions of E2 remain unclear. We hypothesized that E2 attenuates increased ET-1-induced vasoconstriction following trauma-hemorrhage via an ER-β-mediated pathway. To study this, aortic rings were isolated from male Sprague-Dawley rats following trauma-hemorrhage with or without E2 treatment, and alterations in tension were determined in vitro. Dose-response curves to ET-1 were determined, and the vasoactive properties of E2, propylpyrazole triol (PPT, ER-α agonist), and diarylpropionitrile (DPN, ER-β agonist) were determined. The results showed that trauma-hemorrhage significantly increased ET-1-induced vasoconstriction; however, administration of E2 normalized ET-1-induced vasoconstriction in trauma-hemorrhage vessels to the sham-operated control level. The ER-β agonist DPN counteracted ET-1-induced vasoconstriction, whereas the ER-α agonist PPT was ineffective. Moreover, the vasorelaxing effects of E2 were not observed in endothelium-denuded aortic rings or by pretreatment of the rings with a nitric oxide (NO) synthase inhibitor. Cyclooxygenase inhibition with indomethacin had no effect on the action of E2. Thus, E2 administration attenuates ET-1-induced vasoconstriction following trauma-hemorrhage via an ER-β-mediated pathway that is dependent on endothelium-derived NO synthesis.

scholarly journals Evidences Suggesting that Distinct Immunological and Cellular Responses to Light Damage Distinguishes Juvenile and Adult Rat Retinas

2019 ◽  
Vol 20 (11) ◽  
pp. 2744
Author(s):  
Anna Polosa ◽  
Shasha Lv ◽  
Wassila Ait Igrine ◽  
Laura-Alexie Chevrolat ◽  
Hyba Bessaklia ◽  
...  
Keyword(s):  
Immune System ◽  
Light Exposure ◽  
Age Related Macular Degeneration ◽  
Light Damage ◽  
Sprague Dawley ◽  
Adult Rat ◽  
Age Related ◽  
Degenerative Disorders ◽  
Sprague Dawley Rats ◽  
Dose Dependent

To unravel the mechanisms behind the higher resistance to light damage of juvenile (JR) versus adult (AR) rats, Sprague Dawley rats were exposed to a bright luminous environment of 10, 000 lux. The light-induced retinopathy (LIR) was assessed with histology, electroretinography and immunohistochemistry (IHC). In JR, 2 days of exposure induced the typical LIR, while >3 days added little LIR. IHC revealed a subtle migration of microglia (Iba1 marker) from the inner to the outer retina after 3 days of exposure in JR contrasting with the stronger reaction seen after 1 day in AR. Similarly, in JR, the Müller cells expressed less intense GFAP, CNTF and FGF2 staining compared to AR. Our results suggest that in JR the degree of retinal damage is not proportional to the duration of light exposure (i.e., dose-independent retinopathy), contrasting with the dose-dependent LIR reported in AR. The immature immune system in JR may explain the delayed and/or weaker inflammatory response compared to AR, a finding that would also point to the devastating contribution of the immune system in generating the LIR phenotype, a claim also advanced to explain the pathophysiology of other retinal degenerative disorders such as Age-related Macular Degeneration, Diabetic Retinopathy and Retinitis Pigmentosa.

Region-specific and Agent-specific Dilation of Intracerebral Microvessels by Volatile Anesthetics in Rat Brain Slices 

1997 ◽  
Vol 87 (5) ◽  
pp. 1191-1198 ◽  
Author(s):  
Neil E. Farber ◽  
Christopher P. Harkin ◽  
Jennifer Niedfeldt ◽  
Antal G. Hudetz ◽  
John P. Kampine ◽  
...  
Keyword(s):  
Brain Slices ◽  
Volatile Anesthetics ◽  
Sprague Dawley ◽  
Cerebral Microvessels ◽  
Cerebrovascular Resistance ◽  
Institutional Review ◽  
Sprague Dawley Rats ◽  
Artificial Cerebrospinal Fluid ◽  
Dose Dependent ◽  
Brain Slice Preparation

Background Volatile anesthetics are potent cerebral vasodilators. Although the predominant site of cerebrovascular resistance is attributed to intracerebral arterioles, no studies have compared the actions of volatile anesthetics on intraparenchymal microvessels. The authors compared the effects of halothane and isoflurane on intracerebral arteriolar responsiveness in hippocampal and neocortical microvessels using a brain slice preparation. Method After Institutional Review Board approval, hippocampal or neocortical brain slices were prepared from anesthetized Sprague-Dawley rats and placed in a perfusion-recording chamber, superfused with artificial cerebrospinal fluid. Arteriolar diameters were monitored with videomicroscopy before, during, and after halothane or isoflurane were equilibrated in the perfusate. PGF2alpha preconstricted vessels before anesthetic administration. A blinded observer using a computerized videomicrometer analyzed diameter changes. Results Baseline microvessel diameter and the degree of preconstriction were not different between groups. In the hippocampus, the volatile agents produced similar, concentration-dependent dilation (expressed as percent of preconstricted control +/- SEM) of 68 +/- 6% and 79 +/- 9% (1 MAC) and 120 +/- 3% and 109 +/- 5% (2 MAC) (P &lt; 0.05) during halothane and isoflurane, respectively. In the cerebral cortex, isoflurane caused significantly less vasodilation than did similar MAC levels of halothane (84 +/- 9% vs. 42 +/- 5% dilation at 1 MAC; 121 +/- 4% vs. 83 +/- 5% dilation at 2 MAC halothane vs. isoflurane, respectively). Conclusion Halothane and isoflurane differentially produce dose-dependent dilation of intraparenchymal cerebral microvessels. These findings suggest that local effects of the volatile anesthetics on intracerebral microvessel diameter contribute significantly to alterations in cerebrovascular resistance and support previously described heterogeneous actions on cerebral blood flow produced by these agents.

Effects of endothelin in portal hypertensive rats

1992 ◽  
Vol 83 (2) ◽  
pp. 165-170 ◽  
Author(s):  
Pi-Chin Yu ◽  
Jon-Son Kuo ◽  
Han-Chieh Lin ◽  
May C. M. Yang
Keyword(s):  
Blood Pressure ◽  
Portal Hypertension ◽  
Portal Vein ◽  
Venous Pressure ◽  
Portal Venous Pressure ◽  
Portal Vein Ligation ◽  
Sprague Dawley ◽  
Hypertensive Rats ◽  
Endothelin 1 ◽  
Sprague Dawley Rats

1. Effects of endothelin-1 on systemic arterial blood pressure, heart rate and portal venous pressure were compared in normal Sprague-Dawley rats and rats with portal hypertension induced by CCl4 and partial portal vein ligation. 2. Endothelin-1 produced biphasic effects on systemic blood pressure and portal venous pressure in all three groups of rats. However, the magnitude of the changes in blood pressure was less in portal hypertensive rats. 3. The ability of endothelin-1 to increase the portal venous pressure was also significantly diminished in portal hypertensive rats. On the other hand, the initial decrease in portal pressure was augmented in rats with partial portal vein ligation, and disappeared at higher dosage in CCl4-treated rats. 4. In accordance with the pressure recording in vivo, the dose-response vasoconstrictive activity of endothelin-1 was significantly attenuated in the intrahepatic vasculature. 5. The plasma immunoreactive endothelin concentration was significantly higher (5.55 ± 0.81 fmol/ml) in Sprague-Dawley rats than in CCl4-treated rats (2.83 ± 0.56 fmol/ml) and rats with partial portal vein ligation (2.68 ± 0.53 fmol/ml). 6. It was concluded that a lower plasma level of endothelin and a reduced vascular responsiveness may contribute, at least in part, to the hyperdynamics of portal hypertension.

scholarly journals Pulmonary Toxicity, Distribution, and Clearance of Intratracheally Instilled Silicon Nanowires in Rats

2012 ◽  
Vol 2012 ◽  
pp. 1-17 ◽  
Author(s):  
Jenny R. Roberts ◽  
Robert R. Mercer ◽  
Rebecca S. Chapman ◽  
Guy M. Cohen ◽  
Sarunya Bangsaruntip ◽  
...  
Keyword(s):  
Silicon Nanowires ◽  
Pulmonary Toxicity ◽  
Lung Damage ◽  
Collagen Deposition ◽  
Wire Length ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Dose Dependent ◽  
Over Time

Silicon nanowires (Si NWs) are being manufactured for use as sensors and transistors for circuit applications. The goal was to assess pulmonary toxicity and fate of Si NW using anin vivoexperimental model. Male Sprague-Dawley rats were intratracheally instilled with 10, 25, 50, 100, or 250 μg of Si NW (~20–30 nm diameter; ~2–15 μm length). Lung damage and the pulmonary distribution and clearance of Si NW were assessed at 1, 3, 7, 28, and 91 days after-treatment. Si NW treatment resulted in dose-dependent increases in lung injury and inflammation that resolved over time. At day 91 after treatment with the highest doses, lung collagen was increased. Approximately 70% of deposited Si NW was cleared by 28 days with most of the Si NW localized exclusively in macrophages. In conclusion, Si NW induced transient lung toxicity which may be associated with an early rapid particle clearance; however, persistence of Si NW over time related to dose or wire length may lead to increased collagen deposition in the lung.

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