Diverse Patterns of Perilymphatic Space Enhancement in the Rat Inner Ear after Intratympanic Injection of Two Different Types of Gadolinium: A 9.4-Tesla Magnetic Resonance Study

2015 ◽  
Vol 20 (2) ◽  
pp. 112-116 ◽  
Author(s):  
Mina Park ◽  
Ho Sun Lee ◽  
Jun-Jae Choi ◽  
Hyeonjin Kim ◽  
Jun Ho Lee ◽  
...  
Keyword(s):  
Inner Ear ◽  
Sprague Dawley ◽  
Mr Images ◽  
Basal Turn ◽  
Sprague Dawley Rats ◽  
Different Types ◽  
Intratympanic Injection ◽  
The Right ◽  
Perilymphatic Space

Objective: To compare the quality of perilymphatic enhancement in the rat inner ear after intratympanic injection of two types of gadolinium with a 9.4-tesla micro-MRI. Materials and Methods: Gadolinium was injected into the middle ear in 6 Sprague-Dawley rats via the transtympanic route. The left ear was injected with Gd-DO3A-butrol first, and then the right ear was injected with Gd-DOTA. MR images of the inner ear were acquired 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, and 4 h after intratympanic (IT) injection using an Agilent MRI system 9.4T/160/AS. The normalized signal intensity was quantitatively analyzed at the scala vestibuli (SV), scala media, and scala tympani (ST) using a Marosis M-view system. Then the normalized signal intensities (SIs) were compared between the two contrast agents. Results: For Gd-DO3A-butrol, the SI was as low as 1.0-1.5 throughout 1-4 h at the SV and ST of the basal turn. The maximum SI was 1.5 ± 0.5 at the SV (2 h) and 1.3 ± 0.5 at the ST (2 h). For Gd-DOTA, the 1-hour postinjection SI at the basal turn was 2.5 ± 0.5 at the SV, 1.6 ± 0.3 at the ST, and 1.2 ± 0.3 at the scala media. In the apical turn, the maximum SI was reached after 2.5 h. The maximum SI in the apical turn was 1.8 ± 0.4 at the SV (3.5 h), 1.8 ± 0.4 at the ST (4 h), and 1.4 ± 0.3 at the scala media (4 h). Conclusions: We were able to clearly visualize and separate the ST and SV using IT Gd and 9.4-tesla micro-MRI. We recommend using Gd-DO3A-butrol over Gd-DOTA and to perform the MRI 2.5 h after using IT Gd in the rat inner ear.

Effects of remote ischemic preconditioning on the deformability and aggregation of red blood cells in a rat endotoxemia model

2021 ◽  
pp. 1-9
Author(s):  
Yun-Hee Kim ◽  
Sung-Uk Choi ◽  
Jung-Min Youn ◽  
Seung-Ha Cha ◽  
Hyeon-Ju Shin ◽  
...  
Keyword(s):  
Ischemic Preconditioning ◽  
Remote Ischemic Preconditioning ◽  
Sprague Dawley ◽  
Aggregation Index ◽  
Sprague Dawley Rats ◽  
Endotoxemia Model ◽  
Elongation Index ◽  
The Right ◽  
Phosphate Buffered Saline ◽  
Severe Ischemia

BACKGROUND: The prevention of rheologic alterations in erythrocytes may be important for reducing sepsis-associated morbidity and mortality. Remote ischemic preconditioning (RIPC) has been shown to prevent tissue damage caused by severe ischemia and mortality resulting from sepsis. However, the effect of RIPC on erythrocytes in sepsis is yet to be determined. OBJECTIVE: To investigate the effect of RIPC on rheologic alterations in erythrocytes in sepsis. METHODS: Thirty male Sprague-Dawley rats were used in this study. An endotoxin-induced sepsis model was established by intraperitoneally injecting 20 mg/kg LPS (LPS group). RIPC was induced in the right hind limb using a tourniquet, with three 10-minute of ischemia and 10 min of reperfusion cycles immediately before the injection of LPS (RIPC/LPS group) or phosphate-buffered saline (RIPC group). The aggregation index (AI), time to half-maximal aggregation (T1/2), and maximal elongation index (EImax) of the erythrocytes were measured 8 h after injection. RESULTS: The AI, T1/2, and EImax values in the LPS and RIPC/LPS groups differed significantly from those in the RIPC group, but there were no differences between the values in the LPS and RIPC/LPS groups. CONCLUSIONS: RIPC did not prevent rheologic alterations in erythrocytes in the rat model of LPS-induced endotoxemia.

Effects of prior adrenalectomy on postpneumonectomy lung growth in the rat

1985 ◽  
Vol 248 (1) ◽  
pp. E70-E74 ◽  
Author(s):  
R. A. Bennett ◽  
P. C. Colony ◽  
J. L. Addison ◽  
D. E. Rannels
Keyword(s):  
Dry Mass ◽  
Hydrocortisone Acetate ◽  
Lung Growth ◽  
Sprague Dawley ◽  
Treatment Groups ◽  
Compensatory Lung Growth ◽  
Sprague Dawley Rats ◽  
Total Dna ◽  
Glucocorticoid Replacement Therapy ◽  
The Right

The effects of adrenalectomy, with and without subsequent glucocorticoid replacement therapy, on postpneumonectomy compensatory lung growth in the rat were investigated. Male Sprague-Dawley rats (200-230 g) were subjected to no operation (UNOP), left pneumonectomy (PNX), or PNX preceded by bilateral adrenalectomy 5 days earlier (ADX/PNX). At 14 days post-PNX, when compensatory lung growth is normally complete in 200-g rats, right lung (RL) dry weights of PNX (263 +/- 6 mg, n = 26) and ADX/PNX (334 +/- 13 mg, n = 25) rats were increased 58 and 101%, respectively, relative to UNOP controls (166 +/- 5 mg, n = 10). Increases in total DNA, RNA, and protein in the right lungs of PNX and ADX/PNX rats occurred in proportion to RL dry mass. The increase in all parameters examined in PNX and ADX/PNX rats at 7 days post-PNX was half that at 14 days, indicating linear lung growth in both treatment groups. The stimulatory effect of ADX on lung growth was blocked by hydrocortisone acetate (HCA), administered intraperitoneally in daily doses of 5 mg/kg, beginning on the day of PNX. The RL dry weights of HCA-treated ADX/PNX rats (241 +/- 7 mg, n = 10) did not differ significantly from the corresponding value in PNX rats (270 +/- 14 mg, n = 7). The lower RL weights in the HCA-treated rats resulted from an inhibition of cell division, as evidenced by the total RL DNA content, which was similar to that in PNX animals.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Contralateral spreading of substances following intratympanic nanoparticle-conjugated gentamicin injection in a rat model

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Sang-Yeon Lee ◽  
Jeonghyo Kim ◽  
Sangjin Oh ◽  
Gaon Jung ◽  
Ki-Jae Jeong ◽  
...  
Keyword(s):  
Eustachian Tube ◽  
Rat Model ◽  
Control Group ◽  
Fluorescent Nanoparticles ◽  
Sprague Dawley ◽  
Surface Charges ◽  
Cochlear Hair Cells ◽  
Intratympanic Injection ◽  
Group 2 ◽  
The Right

Abstract This study was performed to investigate the Eustachian tube as a potential route for contralateral spreading following intratympanic nanoparticle (NP)-conjugated gentamicin injection in a rat model. Sprague–Dawley rats were divided into three groups and substances were injected in the right ear: group 1 (fluorescent magnetic nanoparticles [F-MNPs], n = 4), group 2 (F-MNP-conjugated gentamicin [F-MNP@GM], n = 2), and control group (no injections, n = 2). T2-weighted sequences corresponding to the regions of interest at 1, 2, and 3 h after intratympanic injection were evaluated, along with immunostaining fluorescence of both side cochlea. The heterogeneous signal intensity of F-MNPs and F-MNP@GM on T2-weighted images, observed in the ipsilateral tympanum, was also detected in the contralateral tympanum in 4 out of 6 rats, recapitulating fluorescent nanoparticles in the contralateral cochlear hair cells. Computational simulations demonstrate the contralateral spreading of particles by gravity force following intratympanic injection in a rat model. The diffusion rate of the contralateral spreading relies on the sizes and surface charges of particles. Collectively, the Eustachian tube could be a route for contralateral spreading following intratympanic injection. Caution should be taken when using the contralateral ear as a control study investigating inner-ear drug delivery through the transtympanic approach.

scholarly journals Cardiotoxic effects of pavetamine extracted from Pavetta harborii in the rat

2008 ◽  
Vol 75 (3) ◽  
Author(s):  
L. Hay ◽  
R.A. Schultz ◽  
P.J. Schutte
Keyword(s):  
Heart Failure ◽  
Animal Model ◽  
Carotid Artery ◽  
Plant Material ◽  
Active Component ◽  
Systolic Function ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
The Right ◽  
Induce Heart Failure

Previous studies have shown that crude extracts from Pavetta harborii as well as dried plant material have cardiotoxic effects on rats and sheep that can lead to heart failure. The active component has since been isolated and identified. This substance has been named pavetamine. The aim of this study was to determine whether pavetamine has cardiotoxic effects similar to those seen in previous reports, when administered to rats intraperitoneally. Sprague Dawley rats received two doses, initially 4 mg / kg and then 3 mg / kg pavetamine respectively and were monitored for 35 days before cardiodynamic parameters were measured by inserting a fluid-filled catheter into the left ventricle via the right carotid artery. These values were compared to those of control rats that had received only saline. Pavetamine significantly reduced systolic function and body mass in the treated rats, which indicates that it has the potential to induce heart failure in this animal model.

Nitric oxide modulation of glutamatergic, baroreflex, and cardiopulmonary transmission in the nucleus of the solitary tract

2005 ◽  
Vol 288 (1) ◽  
pp. H256-H262 ◽  
Author(s):  
Ana Carolina Rodrigues Dias ◽  
Melissa Vitela ◽  
Eduardo Colombari ◽  
Steven W. Mifflin
Keyword(s):  
Nitric Oxide ◽  
Solitary Tract ◽  
Glutamatergic Transmission ◽  
Sprague Dawley ◽  
Renal Sympathetic Nerve Activity ◽  
Sprague Dawley Rats ◽  
Before And After ◽  
Nos Inhibitor ◽  
The Right ◽  
Oxide Synthase

The neuromodulatory effect of NO on glutamatergic transmission has been studied in several brain areas. Our previous single-cell studies suggested that NO facilitates glutamatergic transmission in the nucleus of the solitary tract (NTS). In this study, we examined the effect of the nitric oxide synthase (NOS) inhibitor NG-nitro-l-arginine methyl ester (l-NAME) on glutamatergic and reflex transmission in the NTS. We measured mean arterial pressure (MAP), heart rate (HR), and renal sympathetic nerve activity (RSNA) from Inactin-anesthetized Sprague-Dawley rats. Bilateral microinjections of l-NAME (10 nmol/100 nl) into the NTS did not cause significant changes in basal MAP, HR, or RSNA. Unilateral microinjection of ( RS)-α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA, 1 pmol/100 nl) into the NTS decreased MAP and RSNA. Fifteen minutes after l-NAME microinjections, AMPA-evoked cardiovascular changes were significantly reduced. N-methyl-d-aspartate (NMDA, 0.5 pmol/100 nl) microinjection into the NTS decreased MAP, HR, and RSNA. NMDA-evoked falls in MAP, HR, and RSNA were significantly reduced 30 min after l-NAME. To examine baroreceptor and cardiopulmonary reflex function, l-NAME was microinjected at multiple sites within the rostro-caudal extent of the NTS. Baroreflex function was tested with phenylephrine (PE, 25 μg iv) before and after l-NAME. Five minutes after l-NAME the decrease in RSNA caused by PE was significantly reduced. To examine cardiopulmonary reflex function, phenylbiguanide (PBG, 8 μg/kg) was injected into the right atrium. PBG-evoked hypotension, bradycardia, and RSNA reduction were significantly attenuated 5 min after l-NAME. Our results indicate that inhibition of NOS within the NTS attenuates baro- and cardiopulmonary reflexes, suggesting that NO plays a physiologically significant neuromodulatory role in cardiovascular regulation.

A Novel Rat Model for Comprehensive Microvascular Training of End-to-End, End-to-Side, and Side-to-Side Anastomoses

2019 ◽  
Vol 35 (07) ◽  
pp. 499-504 ◽  
Author(s):  
Xiaoliang Yin ◽  
Gengfan Ye ◽  
Jun Lu ◽  
Lijun Wang ◽  
Peng Qi ◽  
...  
Keyword(s):  
Animal Model ◽  
Average Length ◽  
Proximal Part ◽  
Distal Portion ◽  
Left Renal Artery ◽  
Sprague Dawley ◽  
Anatomical Dissection ◽  
Sprague Dawley Rats ◽  
End To End ◽  
The Right

Background End-to-end, end-to-side, and side-to-side microvascular anastomoses are the main types of vascular bypass grafting used in microsurgery and neurosurgery. Currently, there has been no animal model available for practicing all three anastomoses in one operation. The aim of this study was to develop a novel animal model that utilizes the rat abdominal aorta (AA), common iliac arteries (CIAs), and the median sacral artery (MSA) for practicing these three types of anastomosis. Methods Eight adult Sprague–Dawley rats were anesthetized and then laparotomized. The AA, MSA, and bilateral CIAs were exposed and separated from the surrounding tissues. The length and diameter of each artery were measured. The relatively long segment of the AA without major branches was selected to perform end-to-end anastomosis. One side of the CIAs (or AA) and MSA were used for end-to-side anastomosis. The bilateral CIAs were applied to a side-to-side and another end-to-side anastomosis. Results Anatomical dissection of the AA, CIAs, and MSA was successfully performed on eight Sprague–Dawley rats; four arterial-to-arterial anastomoses were possible for each animal. The AA trunk between the left renal artery and right iliolumbar arteries was 15.60 ± 0.76 mm in length, 1.59 ± 0.15 mm in diameter, for an end-to-end anastomosis. The left CIA was 1.06 ± 0.08 mm in diameter, for an end-to-side anastomosis with the right CIA. The MSA was 0.78 ± 0.07 mm in diameter, for another end-to-side anastomosis with the right CIA or AA. After finishing end-to-side anastomosis in the proximal part of bilateral CIAs, the distal portion was juxtaposed for an average length of 5.6 ± 0.25 mm, for a side-to-side anastomosis. Conclusion This model can comprehensively and effectively simulate anastomosis used in revascularization procedures and can provide more opportunities for surgical education, which may lead to more routine use in microvascular anastomosis training.

scholarly journals Ghrelin Prevents Cisplatin-Induced Mechanical Hyperalgesia and Cachexia

Endocrinology ◽  
2007 ◽  
Vol 149 (2) ◽  
pp. 455-460 ◽  
Author(s):  
José M. Garcia ◽  
Juan P. Cata ◽  
Patrick M. Dougherty ◽  
Roy G. Smith
Keyword(s):  
Quality Of Life ◽  
Chemotherapeutic Agent ◽  
Thermal Sensitivity ◽  
Mechanical Hyperalgesia ◽  
Behavioral Tests ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Unique Model ◽  
Igf I

Complications induced by the chemotherapeutic agent cisplatin, such as neuropathy and cachexia, occur frequently, are often dose limiting, and have an impact on quality of life and survival in cancer patients. The recently discovered hormone ghrelin is a potent GH secretagogue with orexigenic and neuroprotective properties that may prevent or ameliorate these complications. The objective of this study was to determine the effects of ghrelin administration on mechanical hyperalgesia, anorexia, and cachexia induced by cisplatin. Adult male Sprague-Dawley rats were given cisplatin, ghrelin, ghrelin-cisplatin, or vehicle ip. Food intake and body weight were measured daily. Behavioral tests to assess the development of hyperalgesia were conducted by measuring mechanical and thermal sensitivity. Plasma ghrelin and IGF-I levels were also measured. Our results indicate that ghrelin coadministration inhibited the development of cisplatin-induced mechanical hyperalgesia, anorexia, and cachexia induced by cisplatin. Although ghrelin treatment had no effect on plasma IGF-I levels in control rats, it prevented the decrease in IGF-I levels induced by cisplatin. The attenuation of cisplatin-induced mechanical hyperalgesia induced by ghrelin was correlated with the prevention of cisplatin-induced lowering of IGF-I. In conclusion, ghrelin administration may be useful in the treatment or prevention of chemotherapy induced neuropathy and cachexia. Attenuation of mechanical hyperalgesia in the rat by the hormone ghrelin provides a unique model for elucidating the mechanisms involved, which are essential toward our understanding of these complications.

scholarly journals Restoring ventilatory control using an adaptive bioelectronic system

2018 ◽  
Author(s):  
Ricardo Siu ◽  
James J Abbas ◽  
Brian K Hillen ◽  
Jefferson Gomes ◽  
Stefany Coxe ◽  
...  
Keyword(s):  
Closed Loop ◽  
In Vivo Studies ◽  
Sprague Dawley ◽  
Stimulation Parameters ◽  
Sprague Dawley Rats ◽  
Volume Profile ◽  
Stimulation Pattern ◽  
Stimulation Of

Ventilatory pacing via electrical stimulation of the phrenic nerve or of the diaphragm has been shown to enhance quality of life compared to mechanical ventilation. However, commercially-available ventilatory pacing devices require initial manual specification of stimulation parameters and frequent adjustment to achieve and maintain suitable ventilation over long periods of time. Here, we have developed an adaptive, closed-loop, neuromorphic, pattern-shaping controller capable of automatically determining a suitable stimulation pattern and adapting it to maintain a desired breath volume profile on a breath-by-breath basis. In vivo studies in anesthetized intact and C2-hemisected male Sprague-Dawley rats indicated that the controller was capable of automatically adapting stimulation parameters to attain a desired volume profile. Despite diaphragm hemiparesis, the controller was able to achieve a desired volume in the injured animals that did not differ from the tidal volume observed prior to injury (p=0.39). The closed-loop controller was developed and parametrized in a computational testbed prior to in-vivo assessment. This bioelectronic technology could serve as an individualized and autonomous respiratory pacing approach for support or recovery from ventilatory deficiency.

scholarly journals Effect of sinusoidal electrical cortical stimulation on brain cells

2019 ◽  
Author(s):  
Seungjun Ryu ◽  
Kyung-Tai Kim ◽  
Hyeon Seo ◽  
Jongwook Cho ◽  
Jiyoung Park ◽  
...  
Keyword(s):  
Neurological Diseases ◽  
Cortical Stimulation ◽  
Inhibitory Neurons ◽  
Brain Cells ◽  
Specific Cell ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Different Types ◽  
Dependent Protein ◽  
40 Hz

ABSTRACTBackgroundElectrical cortical stimulation is often used in patients with neurological disorders but it is unclear how it modulates different types of brain cells.ObjectiveThe aim of this study was to determine the effect of sinusoidal electrical brain stimulation (SEBS) on different types of brain cells and to identify the exact types of brain cells that are stimulated.MethodsThe study subjects were 40 male Sprague Dawley rats (weight 300–350 g; age 9 weeks). SEBS was delivered continuously at frequencies of 20, 40, 60, or 100 Hz to the sensory parietal cortex using epidurally placed electrodes for 1 week. Transverse rat brain tissue sections were immunolabeled with calmodulin-dependent protein kinase II and parvalbumin (PV) antibodies and with c-Fos for counting of activated excitatory and inhibitory neurons. Computer simulation was performed to cross-validate the frequency-specific cell stimulation results.ResultsInhibitory neurons were more excited than excitatory neurons after epidural EBS. Most excitatory neural activity was evoked at 40 Hz (p<0.05) and most inhibitory neuronal activity was evoked at 20 Hz (p<0.01). The contralateral sensory cortex was activated significantly more at 40 Hz (p<0.05) and the corticothalamic circuit at 20 Hz (p<0.001). Stimulation-induced excitatory and inhibitory neuronal activation was widest at 20 Hz.ConclusionsEpidural electrical stimulation targets both excitatory and inhibitory neurons and the related neural circuits. Further exploration is needed to identify circuits that promote the plasticity needed for recovery in patients with specific neurological diseases.Graphical Abstract

scholarly journals Thymoquinone enhances sperm DNA integrity in nicotineinduced infertile male rats

2021 ◽  
Vol 18 (6) ◽  
pp. 1219-1225
Author(s):  
Farah Dayana Rosli ◽  
Noor Hashida Hashim ◽  
Yusmin Mohd Yusuf ◽  
Khairul Osman ◽  
Siti Fatimah Ibrahim ◽  
...  
Keyword(s):  
Normal Saline ◽  
Quantitative Polymerase Chain Reaction ◽  
Male Rats ◽  
Control Group ◽  
Dna Integrity ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Sperm Dna ◽  
Potential Benefits

Purpose: To assess the effects of thymoquinone (TQ) on the integrity of sperm DNA in nicotineinduced sperm impairment in rats. Methods: Adult male Sprague Dawley rats were randomized into four equal groups: control group received normal saline orally for 60 days; nicotine group was subcutaneously injected with 5 mg/kg/day nicotine for 30 days and then given normal saline for the next 30 days; TQ group was given normal saline for 30 days followed by TQ at 5 mg/kg/day for 30 days; and nicotine-TQ group received 5 mg/kg of nicotine for 30 days and 5mg/kg of TQ for another 30 days. Sperm DNA breakages were evaluated using Comet assay. The expression levels of protamine 1 (PT1) and transition nuclear protein 2 (Tnp2) genes which are essential for the proper compaction of the sperm DNA were analyzed by quantitative polymerase chain reaction (qPCR). Results: Thymoquinone significantly decreased DNA fragmentation in the sperm of nicotine-treated rats. However, there was no change in PT1 gene expression. Tnp2 was downregulated in the nicotine group and slightly upregulated in nicotine-TQ group (p < 0.05). Conclusion: The results demonstrate the potential benefits of TQ in improving sperm DNA quality of nicotine-induced male infertility.

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