The Standard Peritoneal Permeability Analysis in the Rabbit: A Longitudinal Model for Peritoneal Dialysis

1999 ◽  
Vol 19 (1) ◽  
pp. 56-64 ◽  
Author(s):  
Machteld M. Zweers ◽  
Caroline E. Douma ◽  
Dirk R. De Waart ◽  
Anton B. Van Der Wardt ◽  
Marja M. Ho-Dac-Pannekeet ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Peritoneal Dialysis ◽  
Normal Values ◽  
Rabbit Model ◽  
Low Molecular Weight ◽  
Transport Parameters ◽  
Lymphatic Absorption ◽  
Intraindividual Variation ◽  
Peritoneal Transport ◽  
Peritoneal Permeability

Objective The development of an experimental peritoneal dialysis (PD) model in rabbits to investigate peritoneal transport characteristics during a longitudinal follow-up and to assess normal values of these peritoneal transport parameters. Design Peritoneal transport parameters were determined in conscious, unrestrained rabbits by standard peritoneal permeability analysis adjusted for rabbits (SPAR). In this test a 1-hour dwell with 3.86% glucose dialysate is used. Dextran 70 (1 g/L) was added to the dialysate to allow calculation of fluid kinetics. Dialysate samples were taken before, 10, and 40 minutes after instillation and at the end of the dwell. Blood was drawn at the end of the dwell. Experimental Animals Eighteen female New Zealand White rabbits (2565 g) were included for catheter implantation. SPARs were performed in 15 animals; the other 3 were excluded due to complications. Main Outcome The mass transfer area coefficients (MTACs) of the low molecular weight solutes urea (MTACurea) and creatinine (MTACcr) were calculated. The clearances of albumin (Clalb) and IgG (ClIgG), glucose absorption, and fluid transport were computed. Coefficients of intraindividual variation (Vc) were calculated for these parameters. Results The main complications were catheter obstruction and/or dislocation. Five rabbits underwent uncomplicated PD during a 4-week period. Fifteen SPARs in 15 stable rabbits were performed and analyzed to obtain normal values. Means and standard deviations of the transport parameters were as follows: MTACurea 2.24 ± 0.57 mL/min, MTACcr 1.61 ± 0.30 mL/min, Clalb 52.9 ± 17.2 μL/min, ClIgG 44.5 ± 22.9 μL/min. The transcapillary ultrafiltration rate was 0.66 ± 0.13 mL/min and the lymphatic absorption rate 0.47 ± 0.26 mL/min. The parameters of solute transport were upscaled to those in humans using two different methods. MTACs of low molecular weight solutes in rabbits and patients were of the same order of magnitude, but the clearance of albumin was approximately four times higher in rabbits than in patients, and that of IgG eight times. In all rabbits sieving of sodium was observed. The dialysate/plasma (D/P) of sodium decreased to a minimum at 40 min ( p < 0.003 vs the initial value), followed by a rise to 60 min. The minimal value was 0.884 ± 0.002. The coefficients of variation calculated on 7 rabbits that underwent two or more SPARs were similar to those assessed from the patient data. This indicates stability of the model and reproducibility of the SPAR. Conclusion The conscious rabbit model for PD can be used for repeated studies on peritoneal transport.

Peritoneal Transport Characteristics of Water, Low-Molecular Weight Solutes and Proteins during Long Term Continuous Ambulatory Peritoneal Dialysis

1986 ◽  
Vol 6 (2) ◽  
pp. 61-65 ◽  
Author(s):  
Raymond T. Krediet ◽  
Elisabeth W. Boeschoten ◽  
Floris M.J. Zuyderhoudt ◽  
Lambertus Arisz
Keyword(s):  
Mass Transfer ◽  
Molecular Weight ◽  
Peritoneal Dialysis ◽  
Surface Area ◽  
Low Molecular Weight ◽  
Glucose Kinetics ◽  
Peritoneal Surface ◽  
Peritoneal Transport ◽  
Peritoneal Permeability

Peritoneal transport of water, low-molecular-weight solutes and proteins was studied on 75 occasions in 38 CAPD patients. Maximal ultrafiltration capacity decreased with time on CAPD, while there was an increase in the number of hypertonic bags used and the peritoneal absorption of glucose. A relationship was found between maximal ultrafiltration capacity and glucose kinetics. The duration of CAPD was longer in the patients with poor ultrafiltration, while they had a faster transport of glucose and creatinine, but not of proteins. In the group as a whole, no obvious changes were found in the mass transfer area coefficients of urea, creatinine and glucose, nor in the clearances of albumin and IgG. In the five patients with severe ultrafiltration loss, we found evidence of either decreased or increased peritoneal solute transport. Contrasting findings in transport of small solutes and proteins may reflect increased effective peritoneal surface area combined with decreased peritoneal permeability.

scholarly journals The First Peritonitis Episode Alters the Natural Course of Peritoneal Membrane Characteristics in Peritoneal Dialysis Patients

2015 ◽  
Vol 35 (3) ◽  
pp. 324-332 ◽  
Author(s):  
Anouk T.N. van Diepen ◽  
Sadie van Esch ◽  
Dirk G. Struijk ◽  
Raymond T. Krediet
Keyword(s):  
Peritoneal Dialysis ◽  
Free Water ◽  
Glucose Absorption ◽  
Natural Course ◽  
Control Group ◽  
Peritoneal Membrane ◽  
Transport Parameters ◽  
Lymphatic Absorption ◽  
Peritoneal Transport ◽  
The Impact

ObjectiveLittle or no evidence is available on the impact of the first peritonitis episode on peritoneal transport characteristics. The objective of this study was to investigate the importance of the very first peritonitis episode and distinguish its effect from the natural course by comparison of peritoneal transport before and after infection.ParticipantsWe analyzed prospectively collected data from 541 incident peritoneal dialysis (PD) patients, aged > 18 years, between 1990 and 2010. Standard Peritoneal Permeability Analyses (SPA) within the year before and within the year after (but not within 30 days) the first peritonitis were compared. In a control group without peritonitis, SPAs within the first and second year of PD were compared.Main outcome measurementsSPA data included the mass transfer area coefficient of creatinine, glucose absorption and peritoneal clearances of β–2-microglobulin (b2m), albumin, IgG and α–2-macroglobulin (a2m). From these clearances, the restriction coefficient to macromolecules (RC) was calculated. Also, parameters of fluid transport were determined: transcapillary ultrafiltration rate (TCUFR), lymphatic absorption (ELAR), and free water transport. Crude and adjusted linear mixed models were used to compare the slopes of peritoneal transport parameters in the peritonitis group to the control group. Adjustments were made for age, sex and diabetes.ResultsOf 541 patients, 367 experienced a first peritonitis episode within a median time of 12 months after the start of PD. Of these, 92 peritonitis episodes were preceded and followed by a SPA within one year. Forty-five patients without peritonitis were included in the control group. Logistic reasons (peritonitis group: 48% vs control group: 83%) and switch to hemodialysis (peritonitis group: 22% vs control group: 3%) were the main causes of missing SPA data post-peritonitis and post-control. When comparing the slopes of peritoneal transport parameters in the peritonitis group and the control group, a first peritonitis episode was associated with faster small solute transport (glucose absorption, p = 0.03) and a concomitant lower TCUFR ( p = 0.03). In addition, a discreet decrease in macromolecular transport was seen in the peritonitis group: mean difference in post- and pre-peritonitis values: IgG: -8 μL/min ( p = 0.01), a2m: -4 μL/min ( p = 0.02), albumin: -10 μL/min (p = 0.04). Accordingly, the RC to macromolecules increased after peritonitis: 0.09, p = 0.04.ConclusionsThe very first peritonitis episode alters the natural course of peritoneal membrane characteristics. The most likely explanation might be that cured peritoneal infection later causes long-lasting alterations in peritoneal transport state.

On the change of transport parameters with dwell time during peritoneal dialysis

2020 ◽  
pp. 089686082097151
Author(s):  
Jacek Waniewski ◽  
Joanna Stachowska-Pietka ◽  
Bengt Lindholm
Keyword(s):  
Peritoneal Dialysis ◽  
Clinical Data ◽  
Dwell Time ◽  
Dialysis Fluid ◽  
Transport Parameters ◽  
Satisfactory Description ◽  
Pore Model ◽  
Vasodilatory Effect ◽  
Peritoneal Transport ◽  
Molecular Radius

The transitory change of fluid and solute transport parameters occurring during the initial phase of a peritoneal dialysis dwell is a well-documented phenomenon; however, its physiological interpretation is rather hypothetical and has been disputed. Two different explanations were proposed: (1) the prevailing view—supported by several experimental and clinical studies—is that a vasodilatory effect of dialysis fluid affects the capillary surface area available for dialysis, and (2) a recently presented alternative explanation is that the molecular radius of glucose increases due to the high glucose concentration in fresh dialysis fluid and that this change affects peritoneal transport parameters. The experimental bases for both phenomena are discussed as well as the problem of the accuracy necessary for a satisfactory description of clinical data when the three-pore model of peritoneal transport is applied. We show that the correction for the change of transport parameters with dwell time provides a better fit with clinical data when applying the three-pore model. Our conclusion is in favor of the traditional interpretation namely that the transitory change of transport parameters with dwell time during peritoneal dialysis is primarily due to the vasodilatory effect of dialysis fluids.

Changes in Plasma Prekallikrein, High and Low Molecular Weight Kininogens in Disseminated Intravascular Coagulation

1979 ◽  
Author(s):  
M. Yokouchi ◽  
K. Kosaka ◽  
T. Seki ◽  
M. Ogawara ◽  
R. Miura ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Disseminated Intravascular Coagulation ◽  
Marked Decrease ◽  
Normal Values ◽  
Low Molecular Weight ◽  
Factor Xii ◽  
Kinin System ◽  
Intravascular Coagulation ◽  
Plasma Factor ◽  
Kallikrein Kinin System

Changea in components in kallikrein-kinin system have been studied in 15 cases with disseminated Intravascular coagulation (DIC). Nine out of the total cases had infection and six cases had malignancy as primary diseases. Plasma prekallikrein (FKK) was determined by a radiochemical assay using 3H-TAME according to Imanari et al.(1974). High and low molecular weight kininogens (HMWK and LMWK) were bioassayed according to Uchida and Katori (in press). If plasma factor XII, measured in each case, was less than 50 % of normal, values of PKK and HMWK in examined plasma were caliculated from those in 1:1 mixture of examined plasma and normal plasma. All of PKK, HMWK and LMWK Showed moderate to marked decrease in every case with DIC. The values for PKK, HMWK and LMWK were 0.23 0.07 TAME unit/ml (normally 0.620.13), 0,20 0.07 ug(bradykinin equiv.)/ml (normally 0.66 0.14) and 1.24 0.44 ug/ml (normally 2.57 0.41), respectively. There was a significant correlation between PKK and antithrombin III levels (r=0.66, P 0.001) in those cases with DIC. PKK was also directly correlated with HMWK and factor XII. Decrease in PKK and HMWK may be chiefly due to consumption. The mechanism for reduction In LMWK, however, remains to be determined. It may be concluded that plasma prekallikrein, high and low molecular weight kininogens decrease in DIC.

scholarly journals Effect of Low Molecular Weight Fucoidan and Low Molecular Weight Heparin in a Rabbit Model of Arterial Thrombosis

2008 ◽  
Vol 45 (6) ◽  
pp. 529-537 ◽  
Author(s):  
Eric Durand ◽  
Dominique Helley ◽  
Ayman Al Haj Zen ◽  
Céline Dujols ◽  
Patrick Bruneval ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Arterial Thrombosis ◽  
Low Molecular Weight Heparin ◽  
Rabbit Model ◽  
Low Molecular Weight

scholarly journals Time Course of Peritoneal Function in Automated and Continuous Peritoneal Dialysis

2012 ◽  
Vol 32 (6) ◽  
pp. 605-611 ◽  
Author(s):  
Wieneke M. Michels ◽  
Marion Verduijn ◽  
Alena Parikova ◽  
Elisabeth W. Boeschoten ◽  
Dirk G. Struijk ◽  
...  
Keyword(s):  
Peritoneal Dialysis ◽  
Repeated Measures ◽  
Time Course ◽  
Fluid Transport ◽  
Free Water ◽  
Transport Parameters ◽  
Lymphatic Absorption ◽  
Small Pore ◽  
Year 2000 ◽  
Over Time

♦ Background and ObjectivesIn automated peritoneal dialysis (APD), a patient's peritoneal membrane is more intensively exposed to fresh dialysate than it is in continuous ambulatory peritoneal dialysis (CAPD). Our aim was to study, in incident peritoneal dialysis (PD) patients, the influence of APD—compared with that of CAPD—on peritoneal transport over 4 years.♦ Design, Setting, Participants, and MeasurementsPatients were included if at least 2 annual standard permeability analyses (SPAs) performed with 3.86% glucose were available while the patient was using the same modality with which they had started PD (APD or CAPD). Patients were followed until their first modality switch. Differences in the pattern of SPA outcomes over time were tested using repeated-measures models adjusted for age, sex, comorbidity, primary kidney disease, and year of PD start.♦ ResultsThe 59 CAPD patients enrolled were older than the 47 APD patients enrolled (mean age: 58 ± 14 years vs 49 ± 14 years; p < 0.01), and they had started PD earlier (mean start year: 2000 vs 2002). Over time, no differences in solute ( p > 0.19) or fluid transport ( p > 0.13) were observed. Similarly, free water transport ( p = 0.43) and small-pore transport ( p = 0.31) were not different between the modalities. Over time, patients on APD showed a faster decline in effective lymphatic absorption rate (ELAR: p = 0.02) and in transcapillary ultrafiltration (TCUF: p = 0.07, adjusted p = 0.05). Further adjustment did not change the results.♦ ConclusionsCompared with patients starting on CAPD, those starting on APD experienced a faster decline in ELAR and TCUF. Other transport parameters were not different over time between the groups.

Urine labeling with orally applied marker substances in drug substitution therapy

2004 ◽  
Vol 42 (6) ◽  
Author(s):  
Bernd Huppertz ◽  
Gisela Gauchel ◽  
Heribert Feiertag ◽  
Hermann Schweizer ◽  
Horst Krieger ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Oral Administration ◽  
Normal Values ◽  
Urine Samples ◽  
Outpatient Clinics ◽  
Polyethylene Glycols ◽  
Low Molecular Weight ◽  
Drug Addicts ◽  
Substitution Therapy ◽  
Marker Substances

AbstractThe compliance of 581 drug addicts attending six methadone substitution outpatient clinics was determined over a period of 18 months. Urine from these patients was labeled following oral administration of low molecular weight polyethylene glycols as marker substances. These substances were measured in approx. 5800 urine samples. A protocol for applying marker substances and ways to prevent substitution of urine samples were evaluated. Normal values for marker substances in urine were determined. The results suggest that this labeling procedure is a new diagnostictool to prevent manipulation of urine samples by drug addicts receiving substitution therapy.

How Accurate is the Description of Transport Kinetics in Peritoneal Dialysis According to Different Versions of the Three-Pore Model?

2008 ◽  
Vol 28 (1) ◽  
pp. 53-60 ◽  
Author(s):  
Jacek Waniewski ◽  
Malgorzata Debowska ◽  
Bengt Lindholm
Keyword(s):  
Peritoneal Dialysis ◽  
Solute Transport ◽  
Peritoneal Fluid ◽  
Dwell Time ◽  
Transport Kinetics ◽  
Transport Parameters ◽  
Pore Model ◽  
Peritoneal Transport ◽  
Endogenous Protein ◽  
Dialysate Volume

Objective The three-pore model of peritoneal transport is used extensively for modeling peritoneal fluid and solute transport, but the currently used versions include certain modifications of the transport parameters that have not been validated quantitatively versus detailed data on fluid and solute kinetics. The aim of this study was to evaluate different versions of the three-pore model. Method Detailed clinical peritoneal fluid and solute transport data were obtained from 40 peritoneal dwell studies in clinically stable continuous ambulatory peritoneal dialysis patients in whom the dialysate volume was measured using a macromolecular volume marker (RISA). Results Using a new version of the three-pore model with several adjusted transport parameters, good agreement between the measured and the simulated values of dialysate volume and concentrations of small solutes and RISA (but not of endogenous protein) versus dwell time was obtained; however, the predicted peritoneal absorption for longer than the investigated dwell time would be too high. Conclusion The three-pore model, with some adjustments proposed in this study, may be used for detailed description of peritoneal transport kinetics, but it should be pointed out that, even after these adjustments, it still does not provide the correct description of peritoneal fluid absorption and transport of macromolecules.

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