BACKGROUND: The microcirculation was assessed in the livers of human decay accelerating factors (hDAF) and wild-type transgenic rats by fluorescent intravital microscopy, histology and histomorphology to determine the benefits of hDAF expression for the microcirculation of a rat liver xenograft perfused with human blood. METHODS: Male hDAF transgenic rats (group ...

17beta-estradiol is synthesized de novo in the rat hippocampus. However, the regulatory mechanism of hippocampal estradiol synthesis has remained unclear. We investigated the effects of social isolation on rat hippocampal estradiol synthesis. Rats were divided into two groups: social isolation and pair housed group. Socially isolated rats were housed individually ...

AIM: Transformation and possible metabolic effects of extracellular NAD+ were investigated in the livers of mice (Mus musculus; Swiss strain) and rats (Rattus novergicus; Holtzman and Wistar strains). METHODS: The livers were perfused in an open system using oxygen-saturated Krebs/Henseleit-bicarbonate buffer (pH 7.4) as the perfusion fluid. The transformation of ...

A system is presented demonstrating the high-temporal resolution coupling of low-flow push-pull perfusion sampling (LFPS) to capillary electrophoresis for the absorbance measurement of ascorbate at the rat vitreoretinal interface. This system holds all separation components at a low pressure as the means for withdrawing sample during LFPS. The system uses ...

BACKGROUND AND AIM: The effect of increased sinusoidal pressure on the portal tract in Budd-Chiari syndrome (BCS) is as yet not elucidated. Our aim was to investigate portal changes in a newly-developed rat model for BCS. METHODS: We created an outflow obstruction in Sprague-Dawley rats (n = 6) by diameter ...

197 leaves. Advisor: Harold D. Swanson

BACKGROUND/OBJECTIVE: Carbon monoxide (CO) produced by haem-oxygenase isoforms (HO-1 & HO-2) is involved in the regulation of systemic vascular tone. We aimed to elucidate the vasoregulatory role of CO in the microcirculation in normal and thioacetamide cirrhotic rat livers. METHODS: Haem-oxygenase expression was examined by Western blot. Total HO enzymatic ...

BACKGROUND: Carbon dioxide (CO2) dose-dependently decreases minimum alveolar concentration (MAC) of anaesthetics in rats. CO2 also dose-dependently decreases cerebrospinal fluid pH. N-methyl-D-aspartate (NMDA) channels exhibit pH sensitivity and are putative targets for inhaled anaesthetics. We hypothesized that CO2 dose-dependently decreases rat NMDA channel current via an acidifying effect at concentrations ...

The liver plays a central role in intermediate metabolism. Accumulation of liver fat (steatosis) predisposes to various liver diseases. Steatosis and abnormal muscle energy metabolism are found in insulin-resistant and type-2 diabetic states. To examine hepatic energy metabolism, we measured hepatocellular lipid content, using proton MRS, and rates of hepatic ...

Adenovirus-mediated kallikrein delivery has been shown to promote blood vessel growth in the limb under both ischemic and normoperfused conditions. Here we investigated whether a continuous supply of kallikrein and kinin peptide can induce neovascularization in a rat model of hindlimb ischemia. Rats underwent femoral artery ligation and localized injection ...

The role of haptoglobin in liver cell entry of acellular native hemoglobin, and cross-linked human hemoglobin, a potentially useful oxygen-carrier alternative in transfusion medicine, was examined in the recirculating, perfused rat liver preparation. Doses of tritiated native human or beta-chain [trimesoyl-(Lys82)beta-(Lys82)beta] cross-linked human hemoglobin were preincubated with haptoglobin-containing rat plasma ...

AIM: To investigate whether the major kavalactone kavain imposes adverse effects on the liver ultrastructure and function by affecting vascular and microvascular architecture and altering hepatocellular morphology. METHODS: Kavain solution (10 microg/mL or 43.5 micromol/L) was perfused for 2 h in isolated rat livers. After standard fixation and tissue preparation, ...

PURPOSE: To investigate the value of perfusion-weighted MRI in the evaluation of the intranodular hemodynamic characteristics of dysplastic nodules (DNs) and hepatocellular carcinomas (HCCs) in an experimental rat model. MATERIALS AND METHODS: A total of 40 rats with chemically-induced DNs and HCCs were investigated. Single-slice gadolinium-enhanced perfusion-weighted MRI was performed ...

BACKGROUND: Perihemorrhagic pathophysiology of spontaneous intracerebral hemorrhages (ICH) remains unclear. Recently, ischemic changes in the perihemorrhagic zone (PHZ) have been discussed as a potential source of secondary damage. In this study, we focussed on diffusion and perfusion characteristics of experimental ICH. METHODS: Experimental ICH was induced with a double injection ...

Real-time myocardial contrast echocardiography (MCE) is a noninvasive perfusion imaging method, whereas technical and resolution problems impair its application in small animals. Hence, we investigated the feasibility of MCE in experimental cardiovascular set-ups involving healthy and infarcted myocardium in rats. Twenty-five male Wistar rats were examined under volatile anesthesia (2.5% ...

To investigate the mechanism of the termination of ocular dominance column plasticity by electrophysiologic analysis and 2-dimensional electrophoresis-mass spectrography (2-DE/MS). The changes in ocular dominance columns following monocular deprivation were electrophysiologically detected in 22-day-old, 100-day-old and chondroitinase-perfused 100-day-old rats. Total protein of grey matter of the primary visual cortex was ...

Current techniques for the preservation of donor livers typically rely on cold temperatures (approximately 0-4 degrees C) to slow down metabolic processes. Recently, normothermic extracorporeal liver perfusion (NELP) has regained interest as a potentially promising approach for long-term liver preservation. Unlike cold-storage techniques, NELP attempts to maintain the liver in ...

BACKGROUND/AIMS: Liver function appears to be well maintained in old age. However, the current state of knowledge about liver aging processes is incomplete. In this study, using extracorporeal liver perfusion model, we evaluated the differences between liver function in young and old rats. METHODOLOGY: Livers were harvested from groups of ...

BACKGROUND/AIMS: Cyclooxygenase-1 (COX-1) is overexpressed in sinusoidal endothelial cells (SEC) of cirrhotic rat livers, and through an enhanced production of vasoconstrictor prostanoids contributes to increase intrahepatic resistance. Our study was aimed at investigating the role of enhanced AA bioavailability modulating the hepatic vascular tone of cirrhotic livers and identifying which ...

Liver grafts are frequently discarded due to steatosis. Steatotic livers can be classified as suboptimal and deteriorate rapidly during hypothermic static preservation, often resulting in graft nonfunction. Hypothermic machine perfusion (MP) has been introduced for preservation of donor livers instead of cold storage (CS), resulting in superior preservation outcomes. The ...

PURPOSE: To set up and validate a viable perfused rat pancreas model suitable for pharmacokinetic studies. MATERIALS AND METHODS: We setup and conducted multiple indicator dilution studies in the single pass perfused rat pancreas. The distribution of the reference markers [99mTc]-red blood cells (RBC), [14C]-sucrose, and [3H]-water, and tolbutamide were ...

Isolated perfusion of rat livers (IPRL) represents an attractive set-up to be used as a an evaluative tool in the easy and reproducible assessment of liver injury, allowing for screening of new approaches to organ preservation without the expenditure of actual transplantation experiments. Depending on the pathology under investigation, controversy ...

OBJECTIVE: Baroreflex sensitivity is reduced in women with preeclampsia. The aim of this study was to determine whether baroreflex control of renal sympathetic nerve activity (RSNA) is altered in pregnant rats with reduced uterine perfusion (a model of human preeclampsia). METHODS: Uterine perfusion was reduced in the third trimester by ...

BACKGROUND: Butyrate is the main nutrient for the colonocytes but the effect of the fraction reaching the liver is not totally known. A decrease in tissue ATP content and increase in respiration was previously demonstrated when livers were perfused with short-chain fatty acids (SCFA) such as butyrate, or octanoate. In ...

Mitomycin C (MMC) is an alkylating agent which suppresses allogeneic T-cell responses. We analyzed the effect of graft perfusion with MMC on transplant survival. Hearts from Brown-Norway (BN) rats were perfused ex vivo with MMC-containing solution, stored and implanted into Lewis (LEW) rats. In order to analyze the in vivo ...

The nasal vascular permeability of ovablumin (OVA)-sensitized Brown Norway rats was evaluated by analyzing a brilliant blue concentration in perfusate from the nose after exposure of the nasal mucus to OVA. Oral administration of Lactobacillus GG and L. gasseri TMC0356 significantly inhibited the increase in nasal vascular permeability (P<0.01). The ...

OBJECTIVE: To investigate the effect of Euro-Collins and Belzer solutions in a sequential preservation of the pancreas. METHODS: Forty-five Wistar-EPM rats were divided into four groups, according to the solution used during preservation: (1) saline solution (SF): animals perfused and preserved with saline solution; (2) Euro-Collins group (C): animals perfused ...

The venom of Bothrops insularis snake, known in Brazil as jararaca ilhoa, contains a variety of proteolytic enzymes such as a thrombin-like substance that is responsible for various pharmacological effects. B. insularis venom chromatography profile showed an elution of seven main fractions. The thrombin-like activity was detected in fractions I ...

BACKGROUND: Curcumin has profound antioxidant and anti-inflammatory properties. This research assessed the effect of curcumin on liver preservation. METHODS: Sprague-Dawley rat livers were flushed with different preservation solutions [Euro-Collins solution (EC), phosphate buffer saline (PBS), University of Wisconsin solution (UW)] with or without curcumin (25-200 microM) and stored at 4 ...

The aim of the present study was to investigate the effects of the alpha2-adrenoceptor antagonist yohimbine on blood pressure and heart rate (HR) regulation, as well as on adrenergic and serotoninergic neurotransmission, in fructose hypertensive (F) rats. The anterior hypothalamic area of control (C) and F rats was perfused with ...

Nitrite reduction to nitric oxide (NO) may be potentiated by a nitrite reductase activity of deoxyHb and contribute to systemic hypoxic vasodilation. The effect of nitrite on the pulmonary circulation has not been well characterized. We explored the effect of nitrite on hypoxic pulmonary vasoconstriction (HPV) and the role of ...

OBJECTIVE: University of Wisconsin (UW) solution continues to be the most commonly used solution for intra-abdominal organs. However, it is expensive. Therefore, we have formulated HuaXi-1 (HX-1) solution. The aim of this research was to assess the effect of HX-1 solution compared to UW, Collins 2, and hypertonic citrate solutions ...

Pregnancy is a very important period in mammals. Various morphological and functional changes can be observed. Some studies examining nasal epithelial structure deal with changes found in pregnancy. In this study, a total of 16 adult female Sprague Dawley rats (8 control and 8 pregnant) were used. They were anesthetized ...

Assessment of complement 4 (C4) levels in experimental animals is used as a marker for activation of the classical complement pathway. The objective of this study was to develop a method for measuring C4 concentrations in the rat brain. An ELISA (sensitivity = 0.5 ng C4/ml) was used to measure ...

Homologous or heterologous erythrocytes have been widely used for the estimation of intravascular volume of the liver. However, cross-species blood mediates immune response in the organ, and foreign cells are rapidly cleared from the plasma, indicating that heterologous erythrocytes may not be a suitable marker for determination of vascular space. ...

Carboxy PROXYL is a useful extracellular paramagnetic contrast reagent in electron spin resonance (ESR) and magnetic resonance imaging (MRI). Active transfer of the probe was investigated using an in situ liver model in rats. Carboxy PROXYL, a nitroxyl spin probe, was perfused into in situ liver perfusion system from Wistar ...

We evaluated the effect of ethynylestradiol (EE) administration (5 mg/kg b.wt. s.c., for 5 consecutive days) on the expression and activity of multidrug resistance-associated protein 3 (Mrp3) in rats. Western blotting analysis revealed decreased Mrp2 (-41%) and increased Mrp3 (+200%) expression by EE. To determine the functional impact of up-regulation ...

Development, validation and application of an HPLC assay for new antiviral nucleoside analogues AM365 and AM188 in isolated perfused rat liver perfusate and bile were performed. An analytical column (Phenosphere-NEXT, 250 x 4.6 mm, C(18), 4 microm, Phenomenex) was used in tandem with a guard column (4 x 3 mm, ...

BACKGROUND/AIMS: Cirrhotic livers have a deficient vasodilator response to nitric oxide (NO). The vasodilator effect of NO is normally limited by the degradation of its second messenger cyclic guanosine 3', 5' monophosphate by phosphodiesterases. We investigated (1) the phosphodiesterase-5 (PDE-5) expression in normal and cirrhotic rat livers, (2) the location ...

BACKGROUND AND AIMS: Portal hypertension in cirrhosis is mediated in part by increased intrahepatic resistance, reflecting an increased sensitivity of the hepatic microvasculature to vasoconstrictors. Activation of the RhoA/Rho-kinase pathway is essential for contraction of vascular smooth muscle. The aim of this study was to investigate RhoA/Rho-kinase mediated regulation of ...

PURPOSE: To characterize the relationship between applied power and treatment duration in their effect on extent of coagulation produced with a 2.45-GHz microwave applicator in both an ex vivo and a perfused in vivo liver model. MATERIALS AND METHODS: All experimentation was approved by the Institute of Animal Care and ...

We previously showed that naproxen induced the oxidative stress in the liver microsomes and the isolated hepatocytes of rats. In this study, the in situ effect of naproxen on the rat liver tissue was investigated, using the isolated perfused liver from the view-point of the naproxen-induced hepatotoxicity. The leakage of ...

Although rat is the most widely used model of glucocorticoid programming of the fetus, the role of rat placental 11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD2) in the transplacental pharmacokinetics of the naturally occurring glucocorticoid, corticosterone, has not yet been fully elucidated. In this study, expression of 11beta-HSD2 in the rat placenta ...

The initiating event in preeclampsia is thought be to reduced uteroplacental perfusion. Although we have reported previously that chronic reductions in uterine perfusion pressure (RUPP) in pregnant rats results in hypertension and enhanced endothelin production, the factors linking placental ischemia and endothelial cell activation remain unclear. The purpose of this ...

Reduced intrahepatic endothelial nitric oxide synthase (eNOS) activity contributes to the pathogenesis of portal hypertension (PHT) associated with cirrhosis. We evaluated whether asymmetric dimethylarginine (ADMA), a putative endogenous NOS inhibitor, may be involved in PHT associated with cirrhosis. Two rat models of cirrhosis (thioacetamide [TAA]-induced and bile duct excision [BDE]-induced, ...

BACKGROUND: External esophageal perfusion (EEP) with the idea that esophageal perfusion can be controlled with a single ingredient at a constant rate and concentration, might be used to dissect the injurious role of gastro-duodenal secretions for the progression from esophagitis to Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC). This study ...

Recent reports argue that the performance of University of Wisconsin (UW) solution is limited by the presence of hydroxyethyl starch (HES) as an additive, since HES could be responsible for human red blood cell aggregation. We investigated the effect on rat liver preservation of replacing HES in UW solution by ...

OBJECTIVES: We sought to develop and validate a pharmacokinetic model allowing description of the magnetic resonance (MR) signal intensity induced by the hepatobiliary contrast agent Gd-BOPTA and to quantify the overall Gd-BOPTA transport in rat liver. MATERIALS AND METHODS: MR signal intensity was recorded during the perfusion of rat livers ...

The present study was designed to investigate the hepatic disposition of the prodrug AM365 and the generated antiviral guanosine analogue, AM188 in the isolated perfused rat liver (IPL). The livers of rats (n=12) were isolated and perfused with Krebs-Henseleit pH 7.4 buffer to which AM365 was added as a bolus ...

1. The aim of the present study was to investigate the possible hypothalamic antihypertensive effect of metoprolol and its action on aminergic neurotransmission in sham-operated (SO) rats and aortic coarctated (ACo) rats at a chronic hypertensive stage using the microdialysis technique. 2. Hypothalamic metoprolol concentrations and their cardiovascular effects were ...