TY - JOUR
T1 - Association between an increased surface area of peritoneal microvessels and a high peritoneal solute transport rate
AU - Numata, Miwako
AU - Nakayama, Masaaki
AU - Nimura, Satoshi
AU - Kawakami, Makio
AU - Lindholm, Bengt
AU - Kawaguchi, Yoshindo
PY - 2003
Y1 - 2003
N2 - Objective: The peritoneal solute transport rate (PSTR) often increases, especially for small solutes, during long-term peritoneal dialysis (PD) treatment. Although the mechanism by which PSTR increases in PD patients is not known, it is likely that an increased PSTR reflects an increased surface area of the peritoneal capillary and postcapillary venules (microvessels), but this has not previously been investigated. The aim of this study was to clarify the relationship between PSTR and peritoneal microvessel alterations in biopsy specimens of peritoneum obtained from PD patients after various times on PD, and the possible contribution of the duration of PD in relation to these alterations. Design: Tissue from the parletal peritoneum was obtained from 22 PD patients (age 48.5 ± 9.0 years, duration of PD 66.3 ± 46.6 months, incidence of peritonitis 0.3/patient-year). The patients were subdivided into three groups according to duration of PD: zero months (group 0, n = 4), less than 60 months (group I, n = 7), and more than 60 months (group II; n = 11). Methods: For each specimen, the relative microvessel area (RVA) calculated as total area of microvessels/total area of peritoneal field, and the relative microvessel number (RVN), calculated as number of microvessels/total area of peritoneal field, were determined. The ratio RVA/RVN was used to assess the average area of microvessels. The PSTR was evaluated for creatinine, glucose, β2-microglobulin, and albumin using the peritoneal equilibration test. Results: The dialysate-to-plasma concentration ratio (D/P) for creatinine showed a significant positive correlation with both RVA (rho = 0.77, p < 0.001) and RVA/RVN (rho = 0.51, p = 0.01), but not with RVN. The D/P for β2-microglobulin correlated with RVA (rho = 0.51, p = 0.015) but not with RVN or RVA/RVN. No differences were found between the three groups in the values for RVN, whereas there was an apparent significant increase in RVA with time on PD (p < 0.001 for group 0 vs both groups I and II). Furthermore, in high transporters, RVA tended to be higher in group II than in group I. Conclusions: The present study demonstrates for the first time that an increased peritoneal solute transport rate (for both creatinine and β2-microglobulin) is associated with an increased surface area of peritoneal microvessels, especially in patients on long-term PD treatment. This indicates that increased vascularization and/or dilatation of peritoneal microvessels may play a key role in the development of a high PSTR.
AB - Objective: The peritoneal solute transport rate (PSTR) often increases, especially for small solutes, during long-term peritoneal dialysis (PD) treatment. Although the mechanism by which PSTR increases in PD patients is not known, it is likely that an increased PSTR reflects an increased surface area of the peritoneal capillary and postcapillary venules (microvessels), but this has not previously been investigated. The aim of this study was to clarify the relationship between PSTR and peritoneal microvessel alterations in biopsy specimens of peritoneum obtained from PD patients after various times on PD, and the possible contribution of the duration of PD in relation to these alterations. Design: Tissue from the parletal peritoneum was obtained from 22 PD patients (age 48.5 ± 9.0 years, duration of PD 66.3 ± 46.6 months, incidence of peritonitis 0.3/patient-year). The patients were subdivided into three groups according to duration of PD: zero months (group 0, n = 4), less than 60 months (group I, n = 7), and more than 60 months (group II; n = 11). Methods: For each specimen, the relative microvessel area (RVA) calculated as total area of microvessels/total area of peritoneal field, and the relative microvessel number (RVN), calculated as number of microvessels/total area of peritoneal field, were determined. The ratio RVA/RVN was used to assess the average area of microvessels. The PSTR was evaluated for creatinine, glucose, β2-microglobulin, and albumin using the peritoneal equilibration test. Results: The dialysate-to-plasma concentration ratio (D/P) for creatinine showed a significant positive correlation with both RVA (rho = 0.77, p < 0.001) and RVA/RVN (rho = 0.51, p = 0.01), but not with RVN. The D/P for β2-microglobulin correlated with RVA (rho = 0.51, p = 0.015) but not with RVN or RVA/RVN. No differences were found between the three groups in the values for RVN, whereas there was an apparent significant increase in RVA with time on PD (p < 0.001 for group 0 vs both groups I and II). Furthermore, in high transporters, RVA tended to be higher in group II than in group I. Conclusions: The present study demonstrates for the first time that an increased peritoneal solute transport rate (for both creatinine and β2-microglobulin) is associated with an increased surface area of peritoneal microvessels, especially in patients on long-term PD treatment. This indicates that increased vascularization and/or dilatation of peritoneal microvessels may play a key role in the development of a high PSTR.
KW - Capillary
KW - Creatinine
KW - Microvessel angiogenesis
KW - Peritoneal solute transport rate
KW - Peritoneum
KW - β-microglobulin
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U2 - 10.1177/089686080302300204
DO - 10.1177/089686080302300204
M3 - Article
C2 - 12713076
AN - SCOPUS:0037355894
VL - 23
SP - 116
EP - 122
JO - Peritoneal Dialysis International
JF - Peritoneal Dialysis International
SN - 0896-8608
IS - 2
ER -