Use of multiple fluorophores for evaluating microvascular permeability in control rats and rats with sepsis

2007 ◽  
Vol 114 (2) ◽  
pp. 123-130 ◽  
Author(s):  
Ragheb A. Assaly ◽  
Robert H. Habib ◽  
Mustafa Azizi ◽  
Joseph I. Shapiro ◽  
J. David Dignam
Keyword(s):  
Clinical Problem ◽  
Capillary Leak ◽  
Sprague Dawley ◽  
Relative Retention ◽  
Sprague Dawley Rats ◽  
Transcapillary Escape Rate ◽  
Poly Ethylene ◽  
Covalently Linked ◽  
Caecal Ligation And Puncture ◽  
Texas Red

Capillary leak accompanying systemic inflammatory response conditions is a significant clinical problem. In the present study, we describe and verify a method for studying capillary leak that is based on the injection of proteins that differ significantly in size and have spectrally distinguishable fluorophores. Control (n=11) and post-CLP (caecal ligation and puncture; n=14) Sprague–Dawley rats were injected with tracer amounts of albumin and PEG–Alb [albumin covalently linked to methoxy-poly(ethylene glycol)] labelled with fluorescein and Texas Red. Blood samples were withdrawn between 5 min and 144 h, and the fluorescence of the labelled proteins was determined. The relative retention of the PEG–Alb and albumin was assessed via measurement of the TER (transcapillary escape rate; in %/h) and the t50% estimate, defined as the time when the actual concentration reached 50% of its baseline. The concentration–time trends for both albumin and PEG–Alb tracers exhibited two-compartmental behaviour and were analysed using bi-exponential modelling. Retention times were significantly greater for PEG–Alb in both control and CLP rats. TERPEG-Alb was significantly lower than TERalbumin for both control (8.1±5.6 compared with 14.8±7.1 %/h respectively; P<0.01) and CLP (14.8±6.6 compared with 22.5±7.3 %/h respectively; P<0.001) rats. The t50%[PEG–Alb] was substantially greater than the corresponding t50%[albumin] for both control (29.8±9.8 compared with 7.2±2.0 h respectively; P<0.001) and CLP (12.9±5.6 compared with 5.1±1.6 h respectively; P<0.001) rats. The result was similar irrespective of the fluorophore–protein combination, validating the multifluorophore technique. In conclusion, the double-fluorophore approach described in the present study may provide the future basis for a method to quantify capillary leak in disease.

Plasma expansion by polyethylene-glycol-modified albumin

2004 ◽  
Vol 107 (3) ◽  
pp. 263-272 ◽  
Author(s):  
Ragheb A. ASSALY ◽  
Mustafa AZIZI ◽  
David J. KENNEDY ◽  
Cristine AMAURO ◽  
Aiman ZAHER ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Polyethylene Glycol ◽  
Blood Vessels ◽  
Size Exclusion Chromatography ◽  
Human Albumin ◽  
Size Exclusion ◽  
Capillary Leak ◽  
Exclusion Chromatography ◽  
Covalently Linked ◽  
Caecal Ligation And Puncture

Systemic inflammatory response conditions are associated with capillary leak and haemodynamic compromise. Fluid resuscitation to reverse the ensuing hypovolaemia is, however, complicated by the decreased endothelium reflection coefficient to albumin and other colloids. We developed PEG–Alb (albumin covalently linked to polyethylene glycol) as a potential resuscitative agent. PEG was covalently linked to human albumin at multiple sites on the protein. The modified protein was heterogeneous when examined by SDS/PAGE, size-exclusion chromatography and SELDI–TOF MS (surface-enhanced laser-desorption ionization–time of flight MS). Based on size-exclusion chromatography and osmotic pressure data, the effective volume of PEG–Alb is increased 13- to 16-fold compared with unmodified albumin. In an LPS (lipopolysaccharide) model of shock, rats treated with PEG–Alb showed better blood pressure, lower Hct (haematocrit) consistent with haemodilution and less lung injury than rats treated with unmodified albumin or saline. In a CLP (caecal ligation and puncture) model of sepsis, PEG–Alb was more effective than albumin or saline in maintaining blood pressure and in decreasing Hct. When fluorescein-labelled PEG–Alb and Texas Red-labelled albumin were administered to rats with LPS- or CLP-induced shock, PEG–Alb was retained within blood vessels, whereas albumin extravasates into the interstitial space. Based on these data, PEG–Alb appears to be retained within blood vessels in models of capillary leak. PEG–Alb may ultimately be effective in the clinical treatment of shock associated with capillary leak.

scholarly journals Nanoparticle-Mediated Delivery of Emodin via Colonic Irrigation Attenuates Renal Injury in 5/6 Nephrectomized Rats

2021 ◽  
Vol 11 ◽  
Author(s):  
Zhaoyu Lu ◽  
Chunlan Ji ◽  
Xuewen Luo ◽  
Yong Lan ◽  
Lijuan Han ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Intestinal Barrier ◽  
Tubulointerstitial Fibrosis ◽  
Poly Lactic Acid ◽  
Sprague Dawley ◽  
Colonic Irrigation ◽  
Ckd Progression ◽  
Sprague Dawley Rats ◽  
Tlr4 Signaling Pathway ◽  
Poly Ethylene

Our previous study showed that emodin enema modulates gut microbiota and delays CKD progression. However, the poor solubility, limited colonic irrigation retention time, and inadequate colon adhesion of emodin hinder its clinical application. Based on the deficiencies of emodin, we prepared monomethoxy-poly (ethylene glycol)-poly (lactic acid)-chitosan-2-mercaptobenzimidazole nanoparticles with incorporated emodin (emodin-NP) and studied their efficacy in delaying CKD progression. 5/6 nephrectomized Male Sprague Dawley rats were administered via colonic irrigation with emodin-NP every two days for eight weeks. We found that treatment with emodin-NP improved the kidney function of the rats and limited the expansion of tubulointerstitial fibrosis. Treatment with emodin-NP once every two days is comparable to emodin treatment once a day. Furthermore, emodin-NP via colonic irrigation remarkably reduced IL-1β, IL-6, and LPS levels in serum, improved intestinal barrier functions, and downregulated the key proteins (TLR4, MyD88, and NF-κB) expression in intestinal TLR4 signaling pathway. 16S rDNA analyses showed that emodin-NP can regulate microbiota disturbance in CKD. Taken together, these results suggest that emodin-NP alleviates kidney dysfunction and tubulointerstitial fibrosis by mediation through the modification of gut microbiota disorders. Emodin-NP may be a new method to treat CKD.

scholarly journals Electroacupuncture Attenuates Neuropathic Pain and Comorbid Negative Behavior: The Involvement of the Dopamine System in the Amygdala

2021 ◽  
Vol 15 ◽  
Author(s):  
Xue-Hui Zhang ◽  
Chen-Chen Feng ◽  
Li-Jian Pei ◽  
Ya-Nan Zhang ◽  
Liu Chen ◽  
...  
Keyword(s):  
Neuropathic Pain ◽  
Negative Mood ◽  
Clinical Problem ◽  
Glial Fibrillary Acid Protein ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Acid Protein ◽  
Important Clinical Problem ◽  
Chronic Constrictive Injury ◽  
Underlying Mechanisms

Neuropathic pain (NeuP) is an important clinical problem accompanying negative mood symptoms. Neuroinflammation in the amygdala is critically involved in NeuP, and the dopamine (DA) system acts as an important endogenous anti-inflammatory pathway. Electroacupuncture (EA) can improve the clinical outcomes in NeuP, but the underlying mechanisms have not been fully elucidated. This study was designed to assess the effectiveness of EA on pain and pain-related depressive-like and anxiety-like behaviors and explore the role of the DA system in the effects of EA. Male Sprague-Dawley rats were subjected to the chronic constrictive injury (CCI) model to induce NeuP. EA treatment was carried out for 30 min once every other day for 3 weeks. The results showed that CCI caused mechanical hyperalgesia and depressive and anxiety-like behaviors in rats and neuroinflammation in the amygdala, such as an increased protein level of TNFα and IL-1β and activation of astrocytes. EA treatment significantly improved mechanical allodynia and the emotional dysfunction induced by CCI. The effects of EA were accompanied by markedly decreased expression of TNFα, IL-1β, and glial fibrillary acid protein (GFAP) in the amygdala. Moreover, EA treatment reversed CCI-induced down-regulation of DA concentration, tyrosine hydroxylase (TH) expression, and DRD1 and DRD2 receptors. These results suggest that EA-ameliorated NeuP may possibly be associated with the DA system to inhibit the neuroinflammation in the amygdala.

scholarly journals Characteristic MicroRNA Expression Induced by δ-Opioid Receptor Activation in the Rat Liver Under Prolonged Hypoxia

2017 ◽  
Vol 44 (6) ◽  
pp. 2296-2309 ◽  
Author(s):  
Feng Zhi ◽  
Naiyuan Shao ◽  
Lian Xue ◽  
Yuan Xu ◽  
Xuezhi Kang ◽  
...  
Keyword(s):  
Opioid Receptor ◽  
Mirna Expression ◽  
Ischemic Injury ◽  
Clinical Problem ◽  
Receptor Activation ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Δ Opioid Receptor ◽  
Induced Changes ◽  
Hypoxic Ischemic Injury

Background/Aims: Hypoxic/ischemic injury to the liver is a frequently encountered clinical problem with limited therapeutic options. Since microRNAs (miRNAs) are involved in hypoxic/ ischemic events, and δ-opioid receptor (DOR) is protective against hypoxic/ischemic injury, we asked if pharmacological activation of DOR can alter hypoxic events by regulating miRNA expression in the liver. As the first step, the present work aimed at testing the effect of DOR activation on hepatic miRNA expression in hypoxia. Methods: Male Sprague Dawley rats were exposed to hypoxia (9.5-10% O2) for 1, 5, or 10 days with or without DOR activation. The target miRNAs were selected according to TaqMan low-density array (TLDA) data and analyzed by quantitative real-time PCR. Results: We found that: 1) 1-day hypoxia caused the upregulation of 9 miRNAs (miR-7a-5p, miR-10a-5p, miR-25-3p, miR-26b-5p, miR-122-5p, miR-128a-3p, miR-135b-5p, miR-145-5p, and miR-181a-5p) and the downregulation of 2 miRNAs (miR-34a-5p and miR-182); 2) 5 and 10-days hypoxia altered the expression of 4 miRNAs (miR-34c-5p, miR-184, miR-107-3p and miR192-5p); 3) DOR activation shifted the expression of 8 miRNAs (miR-122-5p, miR-146a-5p, miR-30e-5p, miR-128a-3p, miR-182, miR-192-5p miR-107-3p and miR-184) in normoxic condition; and 4) DOR activation modified hypoxia-induced changes in 6 miRNAs (miR-142-5p, miR-145-5p, miR-146a-5p, miR-204-5p, miR-34a-5p and miR-192-5p). Conclusion: Hypoxia significantly modifies the miRNA profile in the liver, while DOR activation can modify the hypoxic modification. Therefore, it is potentially possible to alter hypoxic/ischemic pathophysiology in the liver through DOR pharmacotherapy.

Ultrastructural Investigation of Spontaneous Pituitary Adenomas in Aging Sprague-Dawley Rats

1982 ◽  
Vol 40 ◽  
pp. 216-217
Author(s):  
D. J. McComb ◽  
J. Beri ◽  
F. Zak ◽  
K. Kovacs
Keyword(s):  
Microscopic Study ◽  
Pituitary Adenomas ◽  
Wistar Rats ◽  
Microscopic Level ◽  
Sprague Dawley ◽  
Prolactin Cells ◽  
Light Microscopic Level ◽  
Ultrastructural Investigation ◽  
Sprague Dawley Rats ◽  
Long Evans

Investigation of the spontaneous pituitary adenomas in rat have been limited mainly to light microscopic study. Furth et al. (1973) described them as chromophobic, secreting prolactin. Kovacs et al. (1977) in an ul trastructural investigation of adenomas of old female Long-Evans rats, found that they were composed of prolactin cells. Berkvens et al. (1980) using immunocytochemistry at the light microscopic level, demonstrated that some spontaneous tumors of old Wistar rats could contain GH, TSH or ACTH as well as PRL.

Early Development of Drug-Induced Hepatic Necrosis

1971 ◽  
Vol 29 ◽  
pp. 576-577
Author(s):  
F. G. Zaki ◽  
E. Detzi ◽  
C. H. Keysser
Keyword(s):  
Early Development ◽  
Hepatic Necrosis ◽  
Screening Tests ◽  
Dense Matrix ◽  
Sprague Dawley ◽  
Electron Microscopic ◽  
Drug Induced ◽  
Hepatocellular Damage ◽  
Sprague Dawley Rats ◽  
Microscopic Studies

This study represents the first in a series of investigations carried out to elucidate the mechanism(s) of early hepatocellular damage induced by drugs and other related compounds. During screening tests of CNS-active compounds in rats, it has been found that daily oral administration of one of these compounds at a dose level of 40 mg. per kg. of body weight induced diffuse massive hepatic necrosis within 7 weeks in Charles River Sprague Dawley rats of both sexes. Partial hepatectomy enhanced the development of this peculiar type of necrosis (3 weeks instead of 7) while treatment with phenobarbital prior to the administration of the drug delayed the appearance of necrosis but did not reduce its severity.Electron microscopic studies revealed that early development of this liver injury (2 days after the administration of the drug) appeared in the form of small dark osmiophilic vesicles located around the bile canaliculi of all hepatocytes (Fig. 1). These structures differed from the regular microbodies or the pericanalicular multivesicular bodies. They first appeared regularly rounded with electron dense matrix bound with a single membrane. After one week on the drug, these vesicles appeared vacuolated and resembled autophagosomes which soon developed whorls of concentric lamellae or cisterns characteristic of lysosomes (Fig. 2). These lysosomes were found, later on, scattered all over the hepatocytes.

Ultrastructural investigation of spontaneous pituitary gonadotroph cell adenomas in aging Sprague-Dawley rats

1983 ◽  
Vol 41 ◽  
pp. 702-703
Author(s):  
D. J. McComb ◽  
J. Beri ◽  
F. Zak ◽  
K. Kovacs
Keyword(s):  
Electron Microscopy ◽  
Animal Model ◽  
Epoxy Resin ◽  
Immunoelectron Microscopy ◽  
Tumor Type ◽  
Gonadal Function ◽  
Sprague Dawley ◽  
Male And Female ◽  
Reticulin Fibers ◽  
Sprague Dawley Rats

Gonadotroph cell adenomas of the pituitary are infrequent in human patients and are not invariably associated with altered gonadal function. To date, no animal model of this tumor type exists. Herein, we describe spontaneous gonadotroph cell adenomas in old male and female Sprague-Dawley rats by histology, immunocytology and electron microscopy.The material consisted of the pituitaries of 27 male and 38 female Sprague Dawley rats, all 26 months of age or older, removed at routine autopsy. Sections of formal in-fixed, paraffin-embedded tissue were stained with hematoxylin-phloxine-saffron (HPS), the PAS method and the Gordon-Sweet technique for the demonstration of reticulin fibers. For immunostaining, sections were exposed to anti-rat β-LH, anti-ratβ-TSH, anti-rat PRL, anti-rat GH and anti-rat ACTH 1-39. For electron microscopy, tissue was fixed in 2.5% glutaraldehyde, postfixed in 1% OsO4 and embedded in epoxy-resin. Tissue fixed in 10% formalin, embedded in epoxy resin without osmification, was used for immunoelectron microscopy.

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