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The nitric oxide donor nitroprusside intraperitoneally affects peritoneal permeability in CAPD
C E Douma1, D R de Waart, D G Struijk
1Department of Medicine, Academic Medical Center University of Amsterdam, The Netherlands.
Kidney International
|June 1, 1997
Summary
Nitroprusside administration increased peritoneal membrane permeability and surface area in CAPD patients, enhancing solute transport without affecting peritoneal blood flow. This suggests nitroprusside, a nitric oxide donor, alters peritoneal function by increasing pore size and surface area.
Area of Science:
- Nephrology
- Physiology
- Pharmacology
Background:
- Continuous Ambulatory Peritoneal Dialysis (CAPD) relies on peritoneal membrane function for solute and fluid exchange.
- Nitric oxide (NO) is a signaling molecule with known vasodilatory and permeability-modulating effects.
- Understanding agents that modify peritoneal transport is crucial for optimizing dialysis efficacy.
Purpose of the Study:
- To investigate the effects of intraperitoneal (i.p.) nitroprusside on peritoneal permeability and perfusion in CAPD patients.
- To assess changes in solute transport, peritoneal blood flow, and molecular signaling pathways.
- To evaluate the impact of nitroprusside on the pore structure of the peritoneal membrane.
Main Methods:
- Ten stable CAPD patients underwent peritoneal permeability analysis with and without i.p. nitroprusside.
- Mass transfer area coefficients (MTAC) for CO2 were used to estimate peritoneal blood flow.
- Solute (creatinine, urea, urate, proteins) and metabolite (nitrate, cGMP) levels were measured in plasma and dialysate.
Main Results:
- Nitroprusside significantly increased MTACs for low molecular weight solutes (creatinine, urea, urate), indicating a larger effective peritoneal surface area.
- The restriction coefficients for both low molecular weight solutes and macromolecules decreased, suggesting increased intrinsic permeability and altered size selectivity.
- While peritoneal blood flow (MTAC CO2) remained unchanged, elevated dialysate/plasma cGMP ratios indicated local NO-induced cGMP generation.
Conclusions:
- Intraperitoneal nitroprusside enhances peritoneal membrane permeability and effective surface area in CAPD patients.
- Nitroprusside alters peritoneal transport characteristics by increasing pore sizes and intrinsic permeability, without altering peritoneal blood flow.
- The study provides evidence for local NO-mediated signaling (cGMP generation) influencing peritoneal function.