scholarly journals Clinically relevant concentrations of dexmedetomidine may reduce oxytocin-induced myometrium contractions in pregnant rats

2020 ◽  
Vol 15 (4) ◽  
pp. 451-458
Author(s):  
Dong Joon Kim ◽  
Young Joon Ki ◽  
Bo Hyun Jang ◽  
Seongcheol Kim ◽  
Sang Hun Kim ◽  
...  
Keyword(s):  
Complete Loss ◽  
Organ Bath ◽  
Dependent Manner ◽  
Active Tension ◽  
Sprague Dawley ◽  
Concentration Dependent Manner ◽  
Pregnant Rats ◽  
Uterine Contractions ◽  
Sprague Dawley Rats ◽  
High Doses

Background: Recently, there have been some trials to use dexmedetomidine in the obstetric field but concerns regarding the drug include changes in uterine contractions after labor. We aimed to evaluate the effects of dexmedetomidine on the myometrial contractions of pregnant rats.Methods: In a pilot study, the contraction of the myometrial strips of pregnant Sprague-Dawley rats in an organ bath with oxytocin at 1 mU/ml was assessed by adding dexmedetomidine from 10-6 to 10-2 M accumulatively every 20 min, and active tension and the number of contractions were evaluated. Then, changes in myometrial contractions were evaluated from high doses of dexmedetomidine (1.0 × 10−4 to 1.2 × 10−3 M). The effective concentrations (EC) for changes in uterine contractions were calculated using a probit model.Results: Active tension and the number of contractions were significantly decreased at 10-3 M and 10-4 M dexmedetomidine, respectively (P < 0.05). A complete loss of contractions was seen at 10-2 M. Dexmedetomidine (1.0 × 10−4 to 1.2 × 10−3 M) decreased active tension and the number of contractions in a concentration-dependent manner. The EC95 of dexmedetomidine for inhibiting active tension and the number of contractions was 5.16 × 10-2 M and 2.55 × 10-5 M, respectively.Conclusions: Active tension of the myometrium showed a significant decrease at concentrations of dexmedetomidine higher than 10-3 M. Thus, clinical concentrations of dexmedetomidine may inhibit uterine contractions. Further research is needed for the safe use of dexmedetomidine in the obstetrics field.

Changes in [Ca2+]i induced by several glucose transport-enhancing stimuli in rat epitrochlearis muscle

2003 ◽  
Vol 94 (5) ◽  
pp. 1813-1820 ◽  
Author(s):  
Shin Terada ◽  
Isao Muraoka ◽  
Izumi Tabata
Keyword(s):  
Glucose Transport ◽  
Quantitative Information ◽  
Dependent Manner ◽  
Sprague Dawley ◽  
Concentration Dependent Manner ◽  
Fura 2 ◽  
Sprague Dawley Rats ◽  
Intracellular Ca ◽  
Resting Muscle ◽  
Krebs Henseleit Buffer

The purpose of the present investigation was to establish a method for estimating intracellular Ca2+ concentrations ([Ca2+]i) in isolated rat epitrochlearis muscles. Epitrochlearis muscles excised from 4-wk-old male Sprague-Dawley rats were loaded with a fluorescent Ca2+indicator, fura 2-AM, for 60–90 min at 35°C in oxygenated Krebs-Henseleit buffer. After fura 2 loading and subsequent 20-min incubation, the intensities of 500-nm fluorescence, induced by 340- and 380-nm excitation lights (Ftotal340 and Ftotal380), were measured. The fluorescences specific to fura-2 (Ffura 2340 and Ffura 2380) were calculated by subtracting the non-fura 2-specific component from Ftotal340 and Ftotal380, respectively. The ratio of Ffura 2340 to Ffura 2380 was calculated as R, and the change in the ratio from the baseline value (ΔR) was used as an index of the change in [Ca2+]i. In resting muscle, ΔR was stable for 60 min. Incubation for 20 min with caffeine (3–10 mM) significantly increased ΔR in a concentration-dependent manner. Incubation with hypoxic Krebs-Henseleit buffer for 10–60 min significantly elevated ΔR, depending on the duration of the incubation. Incubation with 50 μM N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide for 20 min significantly elevated ΔR ( P < 0.05). No significant increases in ΔR were observed during incubation for 20 min with 2 mM 5-aminoimidazole-4-carboxamide-1-β-d-ribofuranoside or with 2 mU/ml insulin. These results demonstrated that, by using the fura 2-AM fluorescence method, the changes in [Ca2+]i can be monitored in the rat epitrochlearis muscle and suggest that the method can be utilized to observe quantitative information regarding [Ca2+]i that may be involved in contraction- and hypoxia-stimulated glucose transport activity in skeletal muscle.

Biochemical changes and oxidative stress induced by zearalenone in the liver of pregnant rats

2014 ◽  
Vol 34 (1) ◽  
pp. 65-73 ◽  
Author(s):  
C Zhou ◽  
Y Zhang ◽  
S Yin ◽  
Z Jia ◽  
A Shan
Keyword(s):  
Oxidative Stress ◽  
Messenger Rna ◽  
Experimental Period ◽  
Normal Diet ◽  
Dependent Manner ◽  
Sprague Dawley ◽  
Pregnant Rats ◽  
Sprague Dawley Rats ◽  
Albumin Content ◽  
Dose Dependent

The aim of the present research was to examine the toxic influence of different doses of zearalenone (ZEN) on the liver, especially oxidative stress induced by ZEN on the liver. A total of 48 pregnant Sprague-Dawley rats were randomly assigned into 4 treatments groups with 12 animals in each. The rats were fed with a normal diet treated with 0 mg/kg (control), 50 mg/kg (treatment 1), 100 mg/kg (treatment 2), or 150 mg/kg (treatment 3) ZEN in feed on gestation days (GDs) 0–7 and then all the rats were fed with a normal diet on GDs 8–20. The experimental period lasted 21 days. The results showed that exposure to ZEN induced increase in aspartate amino transferase, alanine aminotransferase, and alkaline phosphatase activities and decrease in total protein and albumin content in a dose-dependent manner and also induce decrease in superoxide dismutase and glutathione peroxidase activities and increase in malondialdehyde content in a dose-dependent manner in the serum and the liver. The increased transcription of cytochrome P450 2E1 (CYP2E1) was detected in the liver after exposure to ZEN. These results suggested that ZEN not only caused damage in the liver of pregnant rats in a dose-dependent manner but also induced the messenger RNA expression of CYP2E1 in the liver.

scholarly journals Inhibitory Effects of Raw-Extract Centella asiatica (RECA) on Acetylcholinesterase, Inflammations, and Oxidative Stress Activities via In Vitro and In Vivo

Molecules ◽  
2020 ◽  
Vol 25 (4) ◽  
pp. 892 ◽  
Author(s):  
Zetty Zulikha Hafiz ◽  
Muhammad ‘Afif Mohd Amin ◽  
Richard Muhammad Johari James ◽  
Lay Kek Teh ◽  
Mohd Zaki Salleh ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Centella Asiatica ◽  
Raw 264.7 Cells ◽  
Dependent Manner ◽  
Sprague Dawley ◽  
Concentration Dependent Manner ◽  
Sprague Dawley Rats ◽  
And Oxidative Stress

Centella asiatica (C. asiatica) is one of the medicinal plants that has been reported to exert comprehensive neuroprotection in vitro and in vivo. In view of this, the present study was performed to investigate the effect of ethanolic extract of C. asiatica, designated as raw-extract of C. asiatica (RECA) in reducing the acetylcholinesterase (AChE), inflammations, and oxidative stress activities via both in vitro (SH-SY5Y and RAW 264.7 cells) and in vivo (Sprague Dawley rats). Quantitative high-performance liquid chromatography analysis reveals that RECA contains a significantly high proportion of glycosides than the aglycones with madecassoside as the highest component, followed by asiaticoside. Treatment of SH-SY5Y cells with RECA significantly reduced the AChE activity in a concentration-dependent manner with an IC50 value of 31.09 ± 10.07 µg/mL. Furthermore, the anti-inflammatory and antioxidant effects of RECA were evaluated by lipopolysaccharides (LPS)-stimulated RAW 264.7 cells. Our results elucidated that treatment with RECA significantly suppressed the level of pro-inflammatory cytokine/mediators and oxidative stress released in a concentration-dependent manner. Interestingly, these patterns of inhibition were consistent as observed in the LPS-induced neuroinflammation Sprague Dawley rats’ model. The highest concentration used in the two models presented the most significant results. Herein, our findings strongly suggest that RECA may offer therapeutic potential for the treatment of Alzheimer’s disease through inhibiting the AChE, inflammation, and oxidative stress activities.

scholarly journals Acute Effects of Vardenafil on Pulmonary Artery Responsiveness in Pulmonary Hypertension

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Edibe Karasu-Minareci ◽  
Irem Hicran Ozbudak ◽  
Gulay Ozbilim ◽  
Gulay Sadan
Keyword(s):  
Pulmonary Hypertension ◽  
Pulmonary Arteries ◽  
Dependent Manner ◽  
Sprague Dawley ◽  
Response Curves ◽  
Concentration Dependent Manner ◽  
Sprague Dawley Rats ◽  
Pathway Activation ◽  
Pulmonary Arterial ◽  
Phosphodiesterase Type

Phosphodiesterase type-5 (PDE-5) inhibitors are novel and important options for the treatment of pulmonary arterial hypertension (PAH). Therefore, we aimed to examine effects of vardenafil, a PDE-5 inhibitor, on the pulmonary arteries isolated from rats with monocrotaline- (MCT-) induced pulmonary hypertension. MCT (60 mg/kg) or its vehicle was administered by a single intraperitoneal injection to 6-week-old male Sprague Dawley rats. Rats were sacrificed 21 days after MCT injection, and the main pulmonary arteries were isolated and then mounted in 20 mL organ baths. Concentration-response curves for vardenafil (10−10–10−5 M) were constructed in phenylephrine- (Phe-) precontracted rings. PAH caused marked rightward shift in the curves to vardenafil whereas maximal responses were not affected. Inhibition of NO synthase (L-NAME, 10−4 M) or guanylyl cyclase (ODQ, 10−5 M) caused similar attenuation in responses evoked by vardenafil. Moreover, contraction responses induced by CaCl2(3×10−5–3×10−2 M) were significantly reduced in concentration-dependent manner by vardenafil. In conclusion, vardenafil induced pulmonary vasodilatation via inhibition of extracellular calcium entry in addition to NO-cGMP pathway activation. These results provide evidence that impaired arterial relaxation in PAH can be prevented by vardenafil. Thus, vardenafil represents a valuable therapeutic approach in PAH besides other PDE-5 inhibitors.

scholarly journals Reduction of the sevoflurane minimum alveolar concentration induced by methadone, tramadol, butorphanol and morphine in rats

2012 ◽  
Vol 46 (3) ◽  
pp. 200-206 ◽  
Author(s):  
Mariana Abreu ◽  
Delia Aguado ◽  
Javier Benito ◽  
Ignacio A Gómez de Segura
Keyword(s):  
Minimum Alveolar Concentration ◽  
Intraperitoneal Administration ◽  
Control Group ◽  
High Dose ◽  
Dependent Manner ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Before And After ◽  
High Doses ◽  
Dose Dependent

This study aimed to estimate the reduction in the minimum alveolar concentration (MAC) of sevoflurane induced by low and high doses of methadone (5 and 10 mg/kg), tramadol (25 and 50 mg/kg), butorphanol (5 and 10 mg/kg) or morphine (5 and 10 mg/kg) in the rat. A control group received normal saline. Sixty-three adult male Sprague-Dawley rats were anaesthetized with sevoflurane ( n = 7 per group). Sevoflurane MAC was then determined before and after intraperitoneal administration of the opioids or saline. The duration of the sevoflurane MAC reduction and basic cardiovascular and respiratory measurements were also recorded. The baseline MAC was 2.5 (0.3) vol%. Methadone, tramadol and morphine reduced the sevoflurane MAC (low dose: 31 ± 10, 38 ± 15 and 30 ± 13% respectively; high dose: 100 ± 0, 83 ± 17 and 77 ± 25%, respectively) in a dose-dependent manner. The low and high doses of butorphanol reduced the sevoflurane MAC to a similar extent (33 ± 7 and 31 ± 4%, low and high doses, respectively). Two rats developed apnoea following administration of high-dose butorphanol and methadone. These anaesthetic-sparing effects are clinically relevant and may reduce the adverse effects associated with higher doses of inhalational anaesthetics.

Influence of Slice Thickness and Culture Conditions on the Metabolism of 7-Ethoxycoumarin in Precision-cut Rat Liver Slices

1998 ◽  
Vol 26 (4) ◽  
pp. 541-548
Author(s):  
Roger J. Price ◽  
Anthony B. Renwick ◽  
Paula T. Barton ◽  
J. Brian Houston ◽  
Brian G. Lake
Keyword(s):  
Gas Phase ◽  
Rat Liver ◽  
Xenobiotic Metabolism ◽  
Culture Conditions ◽  
Slice Thickness ◽  
Dependent Manner ◽  
Sprague Dawley ◽  
Liver Slices ◽  
Sprague Dawley Rats ◽  
Rat Livers

This study investigated the effects of some experimental variables on the rate of xenobiotic metabolism in precision-cut rat liver slices. Liver slices of 123 ± 8μm (mean ± SEM of six slices), 165 ± 3μm, 238 ± 6μm and 515 ± 14μm thickness were prepared from male Sprague-Dawley rats, and incubated in RPMI 1640 medium in an atmosphere of 95% O2/5% CO2 by using a dynamic organ culture system. Liver slices of all thicknesses metabolised 10μM 7-ethoxycoumarin to total (free and conjugated) 7-hydroxycoumarin in a time-dependent manner. The rate of 7-ethoxycoumarin metabolism was greatest in 165μm thick slices and slowest in 515μm thick slices, being 2.74 ± 0.19pmol/minute/mg slice protein and 0.69 ± 0.07pmol/minute/mg slice protein, respectively. No marked effects on the rate of 7-ethoxycoumarin metabolism in liver slices were observed either by changing the medium to Earle's balanced salt solution (EBSS) or by changing the gas phase to 95% air/5% CO2. Moreover, the perfusion of rat livers with EBSS at 2–4°C, prior to preparation of tissue cores, did not enhance 7-ethoxycoumarin metabolism in rat liver slices. In this study, the optimal slice thickness was 175μm, with higher rates of 7-ethoxycoumarin metabolism being observed than with 250μm thick slices, which are often used for studies of xenobiotic metabolism. Variable results were obtained with slices of around 100–120μm thickness, which may be attributable to the ratio between intact hepatocytes and cells damaged by the slicing procedure in these very thin slices.

scholarly journals Dietary conjugated linoleic acid (CLA) induces apoptosis of colonic mucosa in 1,2-dimethylhydrazine-treated rats: a possible mechanism of the anticarcinogenic effect by CLA

2001 ◽  
Vol 86 (5) ◽  
pp. 549-555 ◽  
Author(s):  
Hyun S. Park ◽  
Ji H. Ryu ◽  
Yeong L. Ha ◽  
Jung H. Y. Park
Keyword(s):  
Linoleic Acid ◽  
Conjugated Linoleic Acid ◽  
Control Diet ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Prostaglandin E ◽  
Dependent Manner ◽  
Sprague Dawley ◽  
Tumour Incidence ◽  
Sprague Dawley Rats ◽  
Dietary Conjugated Linoleic Acid

One of the objectives of the present study was to investigate whether 1 % conjugated linoleic acid (CLA) in the diet reduced tumour incidence in the colon of 1,2-dimethylhydrazine (DMH)-treated rats. Colon cancer was induced by injecting 6-week-old, male, Sprague–Dawley rats with 15 mg/kg DMH twice per week for 6 weeks. They were fed either 1 % CLA or a control diet ad libitum for 30 weeks. Dietary CLA significantly decreased colon tumour incidence (P<0·05). Our second objective was to investigate whether apoptosis in the colon mucosa of DMH-treated rats was affected by the amount of dietary CLA and whether the changes in apoptosis were related to those in fatty acid-responsive biomarkers. For this purpose, rats were killed after being fed a diet containing 0 %, 0·5 %, 1 % or 1·5 % CLA for 14 weeks. CLA was undetected in the mucosa of rats fed the 0 % CLA diet and increased to 5·9 mg/g phospholipid in rats fed the 0·5 % diet. The apoptotic index estimated by the terminal deoxynucleotidyl transferase-mediated dUTP nick and labelling technique was increased by 251 % and the 1,2-diacylglycerol content was decreased by 57 % in rats fed 0·5 % CLA. No further changes in these variables were observed when CLA in the diet was raised to 1·0 % or 1·5 %. However, dietary CLA decreased mucosal levels of prostaglandin E2, thromboxane B2 and arachidonic acid in a dose-dependent manner. The present data indicate that dietary CLA can inhibit DMH-induced colon carcinogenesis by mechanisms probably involving increased apoptosis.

Effects of Blood Glucose Changes and Physostigmine on Anesthetic Requirements of Halothane in Rats 

1997 ◽  
Vol 87 (2) ◽  
pp. 354-360 ◽  
Author(s):  
Yumiko Ishizawa ◽  
Shuichiro Ohta ◽  
Hiroyuki Shimonaka ◽  
Shuji Dohi
Keyword(s):  
Blood Glucose ◽  
Blood Glucose Level ◽  
Glucose Level ◽  
Minimum Alveolar Concentration ◽  
Severe Hypoglycemia ◽  
Dependent Manner ◽  
Sprague Dawley ◽  
Control Value ◽  
Sprague Dawley Rats ◽  
Brain Acetylcholine

Background Although hyper- and hypoglycemia induce neurophysiologic changes, there have been no reports on the effects of blood glucose changes on anesthetic requirements. This study examined the effects of hyper- and hypoglycemia on the minimum alveolar concentration (MAC) of halothane in rats. In addition, based on a previous finding that the level of brain acetylcholine was reduced during mild hypoglycemia, the authors examined the influence of physostigmine on MAC during hypoglycemia. Methods In Sprague-Dawley rats, anesthesia was induced and maintained with halothane in oxygen and air. The MAC was determined by observing the response to tail clamping and tested during mild hypoglycemia (blood glucose level, 60 mg/dl) and hyperglycemia (blood glucose level, 300 and 500 mg/dl) induced by insulin and glucose infusion, respectively (experiment 1). The effects of 0.3 and 1.0 mg/kg physostigmine given intraperitoneally on MAC were examined in rats with mild and severe hypoglycemia (blood glucose level, 60 and 30 mg/dl; experiment 2). Results In experiment 1, mild hypoglycemia significantly reduced the MAC of halothane (0.76 +/- 0.03%) compared with the control value (0.92 +/- 0.04%), but hyperglycemia did not change MAC. In experiment 2, mild and severe hypoglycemia reduced MAC of halothane in a degree-dependent manner. Physostigmine (1 mg/kg) had no effect on MAC regardless of blood glucose level, but 0.3 mg/kg reduced MAC. Conclusions Hypoglycemia reduced anesthetic requirements in a degree-dependent manner, whereas hyperglycemia had no effects. Although the mechanism of hypoglycemic MAC reduction needs further investigations, physostigmine studies suggest that this may not be related to inhibition of cholinergic transmission.

The Hepatoprotective Role of Warburgia salutaris and Iso-Mukaadial Acetate on Carbon tetrachloride Intoxicated Rats Model

2021 ◽  
Vol 17 ◽  
Author(s):  
Gideon Ayeni ◽  
Mthokozisi Blessing Cedric Simelane ◽  
Shahidul Islam ◽  
Ofentse Jacob Pooe
Keyword(s):  
Carbon Tetrachloride ◽  
Hepatic Injury ◽  
Antioxidant Properties ◽  
Hepatic Necrosis ◽  
Protective Role ◽  
Dependent Manner ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Isolated Compound

Background: Medicinal plants together with their isolated bioactive compounds are known for their antioxidant properties which constitute therapeutic agents that are routinely employed in the treatment of liver diseases. Aims of the Study: The current study sought to explore the protective role of Warburgia salutaris and its isolated compound, iso-mukaadial acetate against carbon tetrachloride (CCl4)-induced hepatic injury. Methods: Thirty-five male Sprague Dawley rats were divided into seven groups of five animals each and injected with CCl4 to induce hepatic injury. Results: Treatment with the crude extract of W. salutaris and of iso-mukaadial acetate significantly reduced the levels of alkaline phosphatase, alanine and aspartate aminotransaminases, total bilirubin and malondialdehyde in a dose dependent manner, when compared to untreated groups. Liver histology revealed a reduction in hepatic necrosis and inflammation. Conclusion: The current investigation has demonstrated that W. salutaris extract and iso-mukaadial acetate could mitigate the acute liver injury inflicted by a hepatotoxic inducer in rats.

scholarly journals Relaxant effect of quercetin on rabbit isolated bladder smooth muscles contractions

2020 ◽  
Vol 10 (1) ◽  
pp. 61-67
Author(s):  
Hassan Sadraei ◽  
Sabihe Tabesh
Keyword(s):  
Smooth Muscles ◽  
Electrical Field Stimulation ◽  
Negative Control ◽  
Flavonoid Compound ◽  
Drug Candidate ◽  
Control Group ◽  
Organ Bath ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Relaxant Effect

Introduction: Quercetin is a flavonoid compound found in many medicinal plants. Antispasmodic effect of quercetin has been reported in ileum and uterus smooth muscles but not in bladder. Therefore, the objective of this research was to investigate relaxant effect of quercetin in rabbit isolated bladder. Methods: Male rabbit was asphyxiated with carbon dioxide and then sacrificed. The whole bladder was dissected out and placed in oxygenated Tyrode’s solution. Isolated bladder was cut into longitudinal strips and placed in an organ bath for contraction studies. Contractions were induced with KCl (20mM), acetylcholine (5μM) and electrical field stimulation (EFS). Full inhibitory concentration–response curve was constructed for quercetin following addition of above spasmogens. Quercetin was added into the organ bath with 2 fold increments in concentration until maximum response was achieved. Nifedipine was used as positive control group and equivalent volume of quercetin vehicle (water + DMSO) was used as negative control group.Results: Quercetin (4 μg/mL to 640 μg/mL) in a concentration dependent manner inhibited isolated bladder strips contracted by KCl (IC50=159±25 μg/mL), acetylcholine (IC50=43±9.1 μg/mL) and EFS (IC50=38±9.3 μg/mL). In the highest used concentration, quercetin completely removed contractile responses to KCl, acetylcholine and electrical filed stimulation (EFS). Nifedipine totally inhibited KCl response (IC50=115±36 ng/mL) but only partially inhibited acetylcholine and EFS responses. Conclusion: These results confirm the relaxant effect of quercetin on rabbit bladder and if similar effects are seen in human studies, then quercetin would be a suitable drug candidate to be investigated for bladder incontinence.

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