Objective:To investigate the possible influence of nitric oxide (NO) on per
itoneal transport during non infected peritoneal dialysis.
Design: A chronic peritoneal dialysis model in New Zealand White rabbits (2
624 g; range: 2251 - 3034 g) was used. In 13 rabbits, 250 mg/L L-arginine,
a substrate for NO synthesis, was added to 3.86% glucose dialysate. NG-mono
methyl-L-arginine (L-NMMA) 25 mg/L, an inhibitor of NO synthase, was added
to the dialysate in 10 rabbits. Standard peritoneal permeability analyses i
n rabbits (SPAR) were performed to analyze the effects of these interventio
ns on solute and fluid transport during 1-hour dwells. The addition of 4.5
mg/L nitroprusside to the dialysate in 5 separate experiments was used for
validation of this model.
Main outcome: For the transport of urea and creatinine, mass transfer area
coefficients (MTACs) were calculated. Furthermore, the glucose absorption,
the peritoneal albumin clearance, peritoneal fluid kinetics, and the dialys
ate-to-plasma (D/P) ratio of nitrate were calculated.
Results: Nitroprusside caused an 86% (48% - 233%) increase in albumin clear
ance, which is similar to the nitroprusside-induced increase found in human
s. Contrary to the findings in human studies, no effect was found on the cl
earances of urea and creatinine, or on peritoneal fluid kinetics. This sugg
ests a lower sensitivity of the rabbit peritoneal membrane for the effect o
f NO on small-solute transport. L-arginine affected neither the MTACs of ur
ea and creatinine, nor the absorption of glucose. Also, peritoneal fluid ki
netics were similar. Peritoneal albumin clearance increased 18% (-24% - 609
%). This result resembles the NO-mediated effects of nitroprusside. Additio
n of L-NMMA caused no change in the transport rate of small solutes, in alb
umin clearance, or in fluid profile. This result suggests that NO synthase
is not induced during non infected peritoneal dialysis, which accords with
previous studies.
Conclusion:This rabbit dialysis model can be used for analyzing the effects
of interventions on peritoneal permeability characteristics, although the
rabbit peritoneal membrane is probably less sensitive to NO compared to tha
t of humans. L-Arginine-induced effects are similar to those of nitroprussi
de, which suggests that these effects are possibly mediated by NO. Because
L-NMMA did not affect peritoneal transport, it is unlikely that NO is invol
ved in the regulation of peritoneal permeability during stable continuous a
mbulatory peritonealdialysis.