1. The activity of angiotensin converting enzyme (ACE) has been studied on functional parameters of intact isolated preparations of extrapulmonary tissues. The conversion of angiotensin I (A I) to angiotensin II (A II) and the cleavage of bradykinin (BK) were used as indicators of ACE activity. Captopril was employed as ...

1. [1-14C]Propachlor-GSH was perfused at 0.34, 3.4 and 34 mumol/h through the portal vein or the right renal artery of anaesthetized rats with biliary and ureteral cannulas. Urine was the predominant route for elimination of the 14C regardless of the route of perfusion. 2. Mercapturic acid conjugates were found to ...

Liver lipoprotein lipase activity in neonatal (1- and 5-day-old) rats was 2-3-times than in the liver of adult rats. In mid-suckling (15-day-old) or weaned (30-day-old) animals, it was not significantly different from the low activity detected in adult rats. Starvation resulted in a 3-fold increase of lipoprotein lipase activity in ...

In awake normocapnic rats, the density of the total and of the perfused capillary network was determined in 10 brain areas. The density of perfused capillaries was measured by using fluorescein isothiocyanate (FITC) globulin or Evans blue as intravenous marker and by fluorescent microscopy. The density of morphologically existing capillaries ...

The transport of thyroxine from the bloodstream to the brain and the synthesis and secretion of transthyretin (formerly called prealbumin) were studied in rats and in sheep choroid plexus perfused in vitro. Rat choroid plexus contained 4.4 micrograms and rat liver 0.39 micrograms transthyretin mRNA per gram wet tissue. The ...

We investigated the morphological alterations of the esophageal mucosa due to reflux disease by scanning electron microscopy. The esophagi of several rats were perfused with hydrochloric acid in the lower third, which was sealed towards the cardia with an inflatable catheter. Our findings indicate extensive erosion of the esophageal mucosa ...

The purpose of this study was to evaluate the adhesion of HPMA nanoparticles to mucus using a perfused rat ileum test system. Radiolabeled nanoparticles were prepared and deposited onto rat ileal segments in vitro. The segments were perfused and the perfusate was collected in fractions and assayed for radioactivity. Between ...

The isolated perfused rat liver (IPRL) has proven to be a useful model for the study of physiology and pathology of the liver. For research in nonparenchymal cell (NPC) function that includes measurement of cytokine production (eg, TNF), it is necessary to have a sterilized perfusion system. We have modified ...

Pediatric liver transplantation is successful but donor scarcity is a major limitation. We are studying hepatocyte transplantation as an alternative to provide functional hepatic replacement. This report details the study of rat liver perfusion for optimal harvest of hepatocytes and cell implantation. We performed 128 rat liver perfusions using a ...

The effect of perivascular nerve stimulation (PNS) on the release of calcitonin gene-related peptide (CGRP) was examined by radioimmunoassay (RIA) in isolated, perfused rat mesenteric arteries. The released CGRP-like immunoreactivity (CGRP-LI) was identified to be CGRP itself and its oxidized form by combined analysis with RIA and high performance liquid ...

A sex-dependent metabolism of aldosterone has been reported in intact rats. To further characterize the hepatic elimination of aldosterone and its sex dependence, the metabolism of d-[4-14C]aldosterone was studied in isolated perfused liver from male and female Wistar rats, from male rats castrated 3 weeks before experiments, and from younger ...

Studies were made of the mechanism whereby hepatic gluconeogenesis is increased in diabetic ketoacidosis (DKA) despite evidence in vitro of inhibition of gluconeogenesis by systemic acidosis. In perfused livers taken from normal rats, marked inhibition of lactate uptake and glucose output was achieved by simulation of metabolic acidosis in the ...

An effective system for perfusing rat liver using complete tissue culture medium and washed calf erythrocytes as oxygen carriers was devised. Infusion of taurocholate and glucose proved necessary to maintain stable metabolic activity and bile secretion during a 6-hr period. Perfusate pO2, pCO2 and pH values were monitored continuously and ...

1. An improved rat spleen perfusion is described incorporating a method of defibrination which avoids the use of heparin and enables the spleen to be perfused with rat blood for several hours at a haematocrit of 40% and for 12 h or more at a haematocrit of 20%. 2. Glucose ...

1. Semicarbazide-sensitive amine oxidase (SSAO) activity has been demonstrated in the isolated mesenteric arterial bed of the rat in vitro by studying the metabolism of benzylamine (Bz) and tyramine (Tyr) added to the perfusing fluid. 2. Pretreatment of rats with (E)-2-(3',4'-dimethoxyphenyl)-3-fluoroallylamine (MDL72145), a potent inhibitor of SSAO in rat mesenteric ...

3,5-Diethoxycarbonyl-1,4-dihydro-2,6-dimethyl-4-ethylpyridine and its 4-propyl analogue were administered to phenobarbital-pretreated rats. The N-alkylprotoporphyrins (N-alkylPPs) that were isolated from rat livers, viz., N-ethylPP and N-propylPP, were found to have greater ferrochelatase-inhibitory potency than the corresponding synthetic N-alkylPPs. The N-ethylPP that was isolated from rat liver was found to contain 72% of the ...

Isolated rat liver perfusion system has been extensively used for metabolic and functional studies. Results derived from the application of this system may reflect true biochemical changes but they may also be associated with some structural changes. This study was undertaken to correlate the cytological changes and functional integrity of ...

Rat livers have been perfused with a saline control medium or with a perfluorocarbon emulsion containing perfluorodecalin and N,N-perfluorodiethylcyclohexylamine, and the respiratory rates and transmembrane electrical potentials of mitochondria isolated following perfusion have been evaluated. The results indicate that the perfluorocarbon emulsion used, by providing a good oxygen supply to ...

Using continuous microperfusion techniques, we studied the load dependence of bicarbonate reabsorption along cortical distal tubules of the rat kidney and their bicarbonate permeability. Net bicarbonate transport was evaluated from changes in tracer inulin concentrations and total CO2 measurements by microcalorimetry. Bicarbonate permeability was estimated from the flux of total ...

When rats were pretreated by intraplantar or i.v. injection of various inflammatory mediators, the vasopressor effect of i.a. norepinephrine in the subsequently isolated perfused hindlegs of the rats was found to be partly depressed. This vasodepression could also be detected if mediators were directly co-perfused in the isolated hindlegs. The ...

Circulating somatomedin activity reflects the presence of both somatomedins and somatomedin inhibitors, factors which antagonize the growth-promoting actions of somatomedins. Although both are regulated by nutrition, somatomedin inhibitors respond more rapidly than somatomedins to refeeding in fasted animals. To explore the role of the liver in such responses, release of ...

Abstract Experiments examined release of atrial natriuretic factor (ANF), measured by radioimmunoassay, from acutely prepared explants of rat hypothalamus maintained in vitro by intra-arterial perfusion of artificial cerebrospinal fluid. Perfusates collected from intact preparations contained 6.1 +/- 0.6 pg (mean +/- SEM) of ANF per 2-min sample. Following a 3-min ...

This study describes the effect of the delivery route of high-density lipoproteins (HDL) on the ultimate fate of the lipoprotein in the intact rat adrenal. Equal amounts of human (h)-derived affinity-purified apoE-free 125I-labeled HDL3 was given to ethinyl estradiol-treated (i.e., lipoprotein-deficient) rats either intravenously (in vivo route) or by non-recycling ...

1. The isolated perfused rat liver efficiently takes up cysteinyl leukotrienes (LTs) C4, D4, E4 and N-acetyl-LTE4 from circulation. More than 70% of these cysteinyl LTs are excreted from liver into bile within 1 h of onset of a 5 min infusion, while about 5% remain in the liver. About ...

Tubuloglomerular feedback responses were examined in control euvolemic and glomerulonephritic rats 4 wk after administration of antiglomerular basement membrane antibody (AGBM). Single-nephron glomerular filtration rate (SNGFR) was reduced approximately 30% in AGBM rats. Tubuloglomerular feedback responses were also tested with both artificial and native tubular fluid. SNGFR was evaluated at ...

Fluorescein-isothiocyanate dextran (FITC-dextran), a dye confined to the vascular space, was infused via the hepatic artery and portal vein into perfused livers from fed rats treated with diethylnitrosamine for 4 to 5 months. Fluorescence due to FITC-dextran was detected with fiberoptic microlight guides placed on surface nodules of about 5 ...

Rat livers were perfused by the nonrecirculating technique with medium containing [15N]glycine and sodium benzoate. At various times, the isotopic enrichment of hepatic free glycine, hepatic glycyl-tRNA, and perfusate hippurate was measured by GLC-MS. After 60 min, these parameters had reached approximately maximal values. At 90 min, the perfusate hippurate ...

Hydroxylamine (ED50 values, 47 +/- 8.9 nmol and 320 +/- 39 nmol) dilates resistance arterioles of the perfused noradrenaline-preconstricted rat kidney and mesentery. In this respect hydroxylamine was approximately 63x and 320x less potent than acetylcholine (ACh) and 15x and 128x less potent than nitroprusside in the two perfused organs ...

Retrograde isolated liver perfusion has been used to probe acinar functional heterogeneity, but the hemodynamic effects of backward flow have not been characterized. In this study, extraction of a long-chain fatty acid derivative, 12-N-methyl-7-nitrobenzo-2-oxa-1,3-diazol-amino stearate (12-NBDS), was greater during retrograde than during anterograde perfusion of isolated rat liver. To determine ...

Although impairment of drug metabolism by severe hypoxia is well documented in perfused liver preparations, the degree of hypoxia required to produce inhibition of drug elimination pathways in the intact liver has not been defined. In this study, in the isolated perfused rat liver, we examined the relationship between the ...

1. The toxicokinetics of cis- and trans-tetramethrin isomers were investigated using the isolated perfused rat liver preparation. 2. The concentration of cis- and trans-tetramethrin decreased rapidly in the plasma perfusate and was initially replaced by N-(hydroxymethyl)3,4,5,6-tetrahydrophthalimide (MTI) and then by 3,4,5,6-tetrahydrophthalimide (TPI). Plasma perfusate concentrations of the intact cis-isomer were ...

Interaction between glycolysis and mitochondrial oxidations to supply reducing equivalents at high rates for mixed function oxidation was evaluated in the perfused liver after treatment of rats with beta-naphthoflavone. Livers from fasted beta-naphthoflavone-treated rats were employed because rates of 7-ethoxycoumarin O-deethylation were constant (16 mumol/g/hr) for at least 1 hr ...

The possibility that Mg2+ mobilization is stimulated in perfused liver by alpha 1-adrenergic agonists was studied by measuring Mg2+ release in response to 0.5 and 20 microM phenylephrine. During preperfusion exogenous Mg2+ was added to the medium to give 1.2 mM. 5 min before starting the addition of phenylephrine the ...

A postembedding labeling technique was employed to visualize human native low density lipoproteins (LDL) during transcytosis in rat arterial endothelium. For this purpose human LDL was perfused through rat vasculature before fixation and processing for immunoelectron microscopy. The LDL particles were located on sections by anti-human apolipoprotein B-100 (LDL) antibodies ...

The complement fragments C3a and C5a were purified from zymosan-activated human serum by column chromatographic procedures after the bulk of the proteins had been removed by acidic polyethylene glycol precipitation. In the isolated in situ perfused rat liver C3a increased glucose and lactate output and reduced flow. Its effects were ...

This thesis concerns the development and application of a research model for normo- (37°C) and hypothermic (36°C and below) perfusion of the isolated rat liver. three questions were put. Firstly, what is the effect of cooling on function and morphology of the isolated perfused rat liver. ... Zie: Samenvatting

Glucose output was investigated in bivascularly perfused rat liver. Flow rate was 1 ml/min/g from hepatic artery and 2 ml/min/g from portal vein. Basal glucose output (130 +/- 30 microM/min) from bivascularly perfused liver was significantly (p less than 0.02) higher than that (80 +/- 20 microM/min) from usual monovascularly ...

The distribution of cyclic guanosine 3',5' monophosphate (cGMP) producing cells in various organs of the rat were studied immunocytochemically using antibodies raised against formaldehyde-fixed cGMP. Sodium nitroprusside (SNP), a direct activator of guanylate cyclase and vasodilator, was used to enhance cGMP levels. In order to reach all organs optimally, whole ...

Using the isolated and perfused liver of rats, we investigated the effect of starvation on hepatic glucose output and hepatic insulin extraction. The rats were starved for 72 h. The intestines of fed and starved rats were isolated and perfused, and portal venous effluent (PVE) was collected. The liver of ...

The hepatotoxic effects of hyperthermic liver perfusion were investigated in male Fischer 344 rat livers. Perfusions were carried out at 37, 41, 42, 42.5, and 43 degrees C for 2 hr. During the 2 hr, the perfusate was analyzed for activity of aspartate aminotransferase (AST), lactate dehydrogenase (LDH), N-acetyl-beta-glucosaminidase (NAG), ...

Angiotensin II was used as a probe to study the effect of changes in perfusate flow rate on the renal clearance parameters of furosemide in the isolated perfused rat kidney. Drug studies were performed in three rats with no angiotensin II present in the perfusate (treatment I) and in three ...

We report the clearance of rat plasma kallikrein (RPK) by the perfused livers of normal rats and from others at 2 and 4 days after subcutaneous injection of turpentine oil. RPK removal from the perfusate follows a logarithmic curve (y = a+b lnx) and from this equation its half-life of ...

1. 5-Methyluridine perfused through the lumen of isolated loops of rat jejunum gave rise to serosal thymine as the major species transported across the epithelial layer; no serosal 5-methyluridine was detected. 2. At 0.1 mM-luminal 5-methyluridine there was enhanced transmural transport of thymine (P less than 0.001) when compared with ...

The multiple indicator dilution technique was used to investigate octanoate transport in the isolated, perfused rat liver. The form of the octanoate outflow profiles depends on albumin concentration. The steady-state intracellular octanoate concentration and the rate of uptake increase when the albumin concentration is decreased. At physiological albumin concentrations, the ...

Albumin is known to affect the intrinsic clearance of many compounds in the isolated perfused rat liver, but little is known of its effect in vivo. The influence of decreased albumin concentrations on clearance of unbound prazosin and intrinsic clearance of prazosin was therefore studied in vivo in rats that ...

In order to study the events that follow cyanide-induced inhibition of oxidative metabolism and produce cellular injury, isolated, haemoglobin-free perfused rat livers from fasted rats were exposed to KCN (100 mg/l). KCN reduced the oxygen consumption of the livers by about 80%. Hepatotoxicity was evident by a marked release of ...

Formic acid 2-[4-(5-nitro-2-furyl)-2-thiazolyl]-hydrazide (FNT) is a potent renal carcinogen in the rat. This study assessed the metabolism of FNT by the isolated perfused rat kidney and whole rat. The glomerular filtration rate and the fractional excretion of sodium for the isolated perfused kidney indicated that under the conditions of these ...

Striatal and cortical extracellular acetylcholine (ACh) and choline (Ch) levels were determined in samples collected under in vivo conditions using microdialysis in normal (naive) and decorticated rats treated with saline or the monoganglioside GM1. ACh and Ch were assayed using a sensitive high performance liquid chromatography technique coupled to a ...

Using the isolated perfused rat liver preparation, the disappearance from the perfusate and the excretion in the bile of vecuronium bromide and pancuronium bromide and their metabolites were followed for 2 h after the addition of 1 mg of either drug to the perfusate. In addition, the rate of change ...

The relation between the effects of glucagon on oxygen consumption and glycolysis in livers from rats under different metabolic conditions was examined. Respiration of substrate-free perfused livers with different glycolytic fluxes, induced by changes in the pattern of food intake, responds differently to the infusion of 1 nM glucagon. The ...