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At least 109 records · Page 6Linked to original sources
PubMed1988

Secretion of newly synthesized proteins into the extracellular fluid of the rabbit hippocampus.

Extracellular proteins were collected continuously from the hippocampus of the rabbit by slow perfusion of a protein-permeable thin tubing. After pulse labelling with radioactive amino acids via the tubing a rapid appearance of labelled proteins was seen in the extracellular fluid. The half-life of the proteins in the extracellular space varied between 15 min and 2 h. Protein fractions were separated with gel electrophoresis or HPLC. The extracellular fraction differed distinctly from intracellular proteins with respect to the labelling pattern.

Animals↗
PubMed1977

Plasma aldosterone during extracellular fluid volume expansion in patients on regular haemodialysis.

The influence of extracellular fluid volume expansion on the plasma aldosterone concentration (PAC) was investigated in five anephric and six non-nephrectomized patients on regular haemodialysis, and compared to a control group of four anephric and four non-nephrectomized patients. Plasma-renin activity, cortisol, Na+, and K+ were measured together with the PAC during the investigation. In anephric patients the PAC remained constant during the control period as well as during extracellular fluid volume expansion by infusion of 350 mmol of 20% mannitol. In the non-nephrectomized patients PAC diminished after mannitol infusion. The decline in PAC was correlated with the basal levels of PAC and the plasma renin activity. It is concluded that 5% extracellular fluid volume expansion has no direct influence on the regulation of PAC in patients without the renal renin-angiotensin system and that the regulation of PAC in anephric patients in the present investigation is probably mediated by changes in potassium and ACTH.

Adult↗
PubMed1989

Increase in ventilation caused by aminophylline in the absence of changes in ventral medullary extracellular fluid pH and carbon dioxide tension.

A study was designed to investigate the possibility that changes in ventral medullary extracellular fluid carbon dioxide tension (PCO2) and hydrogen ion (H+) concentration mediate the ventilatory stimulation induced by systemic administration of aminophylline. Six cats with peripheral chemodenervation (bilateral carotid sinus nerve and vagal neurotomy) were studied while anaesthetised with chloralose urethane and breathing spontaneously at a regulated, constant, and somewhat raised end tidal PCO2. Variables were measured during steady state normoxaemia and 10 and 30 minutes after administration of 17 mg/kg aminophylline (mean (SD) blood concentration of theophylline 14.2 (1.5) mg/l). Aminophylline resulted in a significant and considerable increase in minute ventilation to 155% and 167% above baseline at 10 and 30 minutes. Mean (SD) values for arterial PCO2 were 5.6 (0.6), 5.6 (0.6), and 5.4 (0.6) kPa at 0, 10, and 30 minutes. Values for the ventral medullary extracellular fluid PCO2 were 7.6 (1.1), 7.5 (1.0), and 7.4 (1.0) kPa and for H+ concentration 62.7 (9.3), 62.6 (9.3), and 63.5 (8.0) nmol/l at 0, 10, and 30 minutes. After aminophylline infusion the PCO2 and H+ concentration of the extracellular fluid did not differ significantly from baseline values. It is concluded that in spontaneously breathing, peripherally chemodenervated cats the considerable increase in ventilation that follows an infusion of aminophylline is not mediated by change in the ventral medullary extracellular fluid PCO2 or hydrogen ion concentration.

Aminophylline↗
PubMed1997

Extracellular fluid pathway inside the facial nerve fascicles.

The extracellular fluid pathway in the facial nerve and the diffusion of a tracer from the facial nerve to other cranial nerves was examined in the rabbit. Sodium fluorescein solution was injected into either the facial nerve fascicles or the epineurial connective tissue as a tracer at the stylomastoid foramen and then localized by fluorescence microscopy. In the facial nerve, fluorescence was observed in the endoneurium and external nerve sheath (epineurium and perineurium) through the geniculate ganglion following injection into the nerve fascicles. The vestibular, trigeminal, and glossopharyngeal ganglia also showed fluorescence on the injection side in ganglion cells and intercellular connective tissues. The results suggested that the endoneurial connective tissue constitutes a diffusion pathway inside the facial nerve fascicles and that the extracellular fluid pathway from the facial nerve to these cranial ganglia may be related to the neural spread of inflammation or neoplastic metastasis.

Animals↗
PubMed1992

Reproducibility of plasma and extracellular fluid volume measurements in critically ill patients.

Plasma and extracellular fluid (ECF) volume measurements may provide valuable complementary data to the hemodynamic measurements currently used to compare fluid infusions in critically ill patients. To assess the reproducibility of plasma and extracellular fluid volume measurements in critically ill patients, we injected 131I-labeled albumin (10 microCi) and 35S-sodium sulfate (50 microCi), respectively, into 15 stable patients on two occasions 150 min apart. Plasma was sampled at 20, 30, and 40 min after each injection and the volume of distribution of each radioisotope was calculated from the extrapolated zero time counts. We found that plasma and ECF volume did not differ significantly between the first (42.4 +/- 4.7 ml/kg and 186 +/- 39 ml/kg) and second (42.8 +/- 5.5 ml/kg and 193 +/- 48 ml/kg) measurements. Specifically, the mean difference between the two measurements was 0.4 +/- 3.2 ml/kg and 7 +/- 17 ml/kg respectively. We conclude that measurements of plasma and ECF volume are reproducible over 150 min in stable critically ill patients.

Adult↗
PubMed1998

Extracellular fluid volume determined by bioelectric impedance and serum albumin in CAPD patients.

AIM: To investigate the relationship between serum albumin and extracellular fluid volume, as measured by multifrequency bioelectrical impedance, in stable patients treated by CAPD. METHOD: Fifty-nine stable CAPD patients were assessed. Serum albumin (bromocresol green) and CRP, age, dialysate to plasma (D/P) creatinine ratio, normalized protein catabolic rate (nPCR), daily urine and peritoneal protein losses, and extracellular fluid volume (Vecf) were measured in each patient. Vecf was calculated as a percentage of actual body weight (Vecf% ABW), of lean body mass derived from anthropometry (Vecf% LBM) and of total body water (Vecf% Vtbw). Comparisons between those with a normal serum albumin (> or = 37 g/l) and those with a low serum albumin (< 37 g/l) were made by Mann-Whitney U test. Correlations with serum albumin were sought by Pearson's test. RESULTS: The D/P creatinine ratio, daily peritoneal and urine protein losses, and extracellular fluid volume (Vecf% LBM and Vecf% Vtbw) were all significantly greater in patients with serum albumin < 37 g/l as compared to those > or = 37 g/l; P < 0.05. Age, CRP, and nPCR were not different. Serum albumin was negatively correlated with Vecf% LBM, r = -0.25; P = 0.05, Vecf% Vtbw, r = -0.39; P = 0.002, and daily urinary albumin loss, r = -0.25, P = 0.06. CONCLUSION: Hypoalbuminaemia is partly dependent on subclinical overhydration in CAPD patients. Serum albumin is negatively correlated with increased extracellular fluid volume and the proportion of Vecf to Vtbw is increased in hypoalbuminaemic patients. Multifrequency bioelectrical impedance is able to identify these abnormalities.

Adult↗
PubMed1987

Increased norepinephrine turnover in the median preoptic nucleus following reduced extracellular fluid volume.

The role of noradrenergic input to fluid balance regulatory systems in the anterior hypothalamus was studied by examination of norepinephrine (NE) turnover during reduction of systemic extracellular fluid volume. Extracellular fluid volume was decreased iso-osmotically by subcutaneous polyethylene glycol (PEG), known to increase thirst and vasopressin secretion. NE turnover was assessed by measuring the decline of NE concentration in brain micropunches after administration of alpha-methyl tyrosine in PEG- or sham-treated groups. Several hypothalamic areas were investigated, including the median preoptic area (MnPO), preoptic area (POA), paraventricular nucleus, supraoptic nucleus (SON), subfornical organ, ventromedial hypothalamus, and posterior hypothalamus. Volume-depleted animals showed significantly increased NE turnover in the MnPO, an important area for integration of fluid balance information. The POA and the SON also showed trends toward increased NE turnover. All other areas showed no difference in NE turnover between volume-depleted and normal animals. These results are consistent with previous findings that NE innervation to the MnPO is important in the control of fluid balance and also support the hypothesis that basal forebrain NE projections facilitate thirst and vasopressin secretion.

Animals↗
PubMedDate not supplied

Inflammation in patients on peritoneal dialysis is associated with increased extracellular fluid volume.

BACKGROUND: Cardiovascular disorders (CD) are the most frequent cause of death in patients on dialysis. CD have been related to increased extracellular fluid volume, peritoneal transport type (PTT), hypertension, and inflammation. Inflammation is in itself a risk factor for mortality. The aim of this study was to assess the relationship of increased extracellular fluid volume, inflammation, and PTT in patients on continuous ambulatory peritoneal dialysis (CAPD) and automated peritoneal dialysis (APD). METHODS: A cross-sectional study was carried out with 20 healthy controls (C), 21 patients on CAPD, and nine patients on APD. Clinical and demographic variables were measured and registered. Peritoneal equilibrium test (PET) was done. Blood volume (BV), total body water (TBW), inferior vena cava diameter during inspiration (IVCDi) and expiration (IVCDe), serum albumin, and serum C-reactive protein (CRP) were measured. RESULTS: All patients on peritoneal dialysis (PD) had at least one sign or symptom of increased extracellular fluid volume, hypertension being the most common. Patients also had higher TBW (C, 60.7 +/- 7.2; APD, 62.6 +/- 8.7; CAPD, 66.1 +/- 8.3, as percentage of body weight, p <0.02), higher BV (C, 7.9 +/- 1.6; APD, 9.8 +/- 2.3; CAPD, 9.6 +/- 2.3, as percentage of body weight, p <0.02), higher DIVCi (C, 2.9 +/- 1.2; APD, 4.6 +/- 2.5; CAPD, 4.5 +/- 2.4 mm/m2 BSA, p <0.02), and higher DIVCe (C, 6.2 +/- 1.7; APD, 8.3 +/- 3.4; CAPD, 8.0 +/- 2.8 mm/m2 BSA, p <0.05). PD patients also had hypoalbuminemia and higher CRP levels. There was significant positive correlation between CRP and DIVCi (r=0.43, p <0.05) and IVCe (r=0.45, p <0.05) and between serum albumin and creatinine dialysate-to-plasma ratio (D/P Cr, r=0.57, p <0.01). Serum albumin and CRP were negatively correlated (r= -0.54, p <0.02). CONCLUSIONS: Patients on PD have increased extracellular fluid volume as compared with healthy controls. Hyperhydration is related to inflammation and to higher peritoneal transport types.

Adult↗
PubMed1991

Estimation of extracellular fluid volume by bromide dilution in infants less than 1000 grams birth weight.

We measured extracellular fluid volume by bromide dilution within 12 h of birth in 32 infants less than 1000 g birth weight. Mean (+/- S.D.) birth weight and gestational age were 763 +/- 123 g and 26 +/- 1 week, respectively. Mean extracellular fluid volume was 360 +/- 86 ml (477 +/- 107 ml/kg). These results are similar to extracellular fluid volume estimates from previous carcass analysis data. Wide variability is observed with both methods suggesting that biologic variability may be important.

Body Weight↗
PubMed1991

[Use of the method of integral rheography of the body for measuring the extracellular fluid volume in children].

To measure the volume of extracellular fluid, integral rheography is suggested. Investigations were carried out in 190 practically normal children aged 3 to 14 years. A well-defined reverse relationship was established between basic resistance and the volume of extracellular fluid. The given conclusion was confirmed by examination of children with the nephrotic syndrome, made during disappearance of edema. In edema, basic resistance was found to be reduced whereas in edema disappearance, it increased.

Adolescent↗
PubMed1992

Enhanced monoamine release in the median preoptic area following reduced extracellular fluid volume in rats.

The role of monoaminergic neural inputs to fluid regulatory systems in the median preoptic nucleus (MnPO) was investigated by examination of monoamine metabolism during reduction of systemic extracellular fluid volume in freely moving rats. Extracellular fluid volume was decreased iso-osmotically by subcutaneous polyethylene glycol (PEG), and extracellular noradrenaline (NA), dopamine (DA), 3,4-dihydroxyphenylacetic acid (DOPAC), and homovanillic acid (HVA) were measured using intracerebral microdialysis techniques. PEG treatments significantly increased NA, DA and DOPAC release in the MnPO area. The results suggest that monoaminergic neural systems in the region of the MnPO are important in the control of extracellular fluid balance.

Animals↗
PubMed1989

Capillary permeability and extracellular fluid volumes in pregnancy-induced hypertension.

1. Capillary permeability was determined by the disappearance rate of Evans Blue dye from plasma in healthy non-pregnant women, normal third-trimester primigravidae and primigravidae with pregnancy-induced hypertension. 2. Extracellular fluid volume was determined from the disappearance curves of injected mannitol in the same subjects and the plasma volume was measured by the Evans Blue dye dilution technique. 3. In normal pregnancy capillary permeability was not altered from that of non-pregnant subjects. Although extracellular fluid volume and plasma volume were increased in normal pregnant compared with non-pregnant women, the distribution of fluid between plasma volume and interstitial fluid volume was unaltered. 4. Women with established pregnancy-induced hypertension had a more rapid Evans Blue disappearance rate and a lower plasma volume than normal pregnant women, independent of the presence of proteinuria. Maternal plasma volume correlated positively and significantly with fetal birth weight in women with pregnancy-induced hypertension, emphasizing the important relationship between maternal plasma volume and fetal outcome. 5. The increased capillary permeability in women with pregnancy-induced hypertension was associated with a reduction in the plasma volume/interstitial fluid volume ratio but a normal extracellular fluid volume, suggesting that the reduced plasma volume did not result from sodium loss but rather from a redistribution of the total extracellular fluid volume. These changes did not differ significantly in subgroups with and without oedema.

Adult↗
PubMed1978

Increase in plasma extracellular fluid volume ratio caused by bilateral nephrectomy in patients on maintenance hemodialysis.

Changes, observed in rats after bilateral nephrectomy, in blood pressure and in the relation betwen plasma volume-extracellular fluid volume or plasma volume-interstitial fluid volume, are consistent with the postulation that the kidney secretes a substance that regulates, to some degree, the compliance of the interstitial space. In order to evaluate the possibility that this also occurs in humans, we have carried out a retrospective analysis of measurements of extracellular fluid volume, plasma volume, and blood volume made prior to and after bilateral nephrectomy in a group of 9 patients. It was observed that significant increases had occurred in both the plasma-extracellular fluid volume ratio (0.22 before, 0.26 after) and in the blood-extracellular fluid volume ratio (0.27 before, 0.32 after). These data are consistent with a reduction in compliance of the interstitial compartment caused by bilateral nephrectomy in man, even though other explanations cannot be excluded.

Adult↗
PubMed1983

Blood and extracellular fluid volume in patients with Bartter's syndrome.

Blood and extracellular fluid volumes were measured in four adult patients with Bartter's syndrome and compared with those of 21 healthy control subjects. Extracellular fluid volumes were significantly lower than in the control group (-7%), whereas blood volumes were within the normal range. Consequently, the ratio of blood volume to interstitial fluid volume was significantly elevated (0.42 v normal 0.35). The results are consistent with the concept that a tubular reabsorption defect is present in Bartter's syndrome.

Adolescent↗
PubMed1988

Uterine vascular permeability, blood flow and extracellular fluid space during implantation in rats.

Vascular permeability to plasma proteins in uterine implantation and non-implantation sites (i.e. dye sites and non-dye sites) was assessed quantitatively by a method which accounts for steady-state volumes of distribution. Extracellular fluid volume and uterine blood flow were also determined. On both the evening of Day 5 and the morning of Day 6, vascular permeability to 125I-labelled human serum albumin, extracellular fluid volume and blood flow were significantly increased in implantation sites compared to non-implantation sites. Vascular permeability in implantation sites was increased significantly between Days 5 and 6, whereas that in non-implantation sites was unchanged. This increase in vascular permeability between Days 5 and 6 was not accompanied by further increases in extracellular fluid volume and blood flow. This result shows a dissociation between vascular permeability and extracellular fluid volume immediately after the onset of implantation and raises important questions as to whether the rat uterus undergoes a truly oedematous response at implantation as has been generally accepted.

Animals↗