Local renal delivery of a natriuretic peptide a renal-enhancing strategy for B-type natriuretic peptide in overt experimental heart failure.
OBJECTIVE
The purpose of this study was to test the hypothesis that local renal delivery of B-type natriuretic peptide (BNP) will overcome renal resistance to BNP without systemic hypotension.


BACKGROUND
BNP has vasodilating, natriuretic, and renin-inhibiting properties. In overt heart failure (HF), there is development of renal resistance to BNP.


METHODS
We defined the cardiorenal and humoral effects of systemic (n = 6) or local renal (n = 7) administration of canine BNP (0.01 microg/kg/min) in 2 separate groups of dogs with pacing-induced subacute overt HF complicated by renal dysfunction. We used a commercially available small (3.1-F) bifurcated renal catheter (FlowMedica Inc., Fremont, California) for direct bilateral infusion of BNP into both renal arteries.


RESULTS
With systemic BNP at this clinically used dose (without the bolus), urine flow increased, but there was only a trend for an increase in urinary sodium excretion and glomerular filtration rate (GFR). In contrast, local renal delivery of BNP resulted in significant diuresis and natriuresis and an increase in GFR. These diuretic and natriuretic responses were greater with local renal BNP compared with systemic BNP, and were associated with increased delivery of BNP to the renal tubules as evident by a greater urinary BNP excretion resulting in a decrease in distal reabsorption of sodium. Importantly, local renal BNP did not result in a significant decrease in mean arterial pressure that was observed with systemic BNP.


CONCLUSIONS
We conclude that local renal BNP delivery is a novel strategy that may overcome renal assistance to BNP in overt HF by increasing local delivery of BNP to the renal tubules.
Department of Internal Medicine, Mayo Clinic College of Medicine, Rochester, Minnesota 55905, USA. chen.horng@mayo.edu
Horng H
HH
Chen
Alessandro
A
Cataliotti
John A
JA
Schirger
Fernando L
FL
Martin
Lynn K
LK
Harstad
John C
JC
Burnett
D000818:Animals; D004195:Disease Models, Animal; D004285:Dogs; D006333:Heart Failure / Q000150:complications*; D006439:Hemodynamics; D007668:Kidney / Q000187:drug effects*; D007674:Kidney Diseases / Q000150:complications / Q000188:drug therapy*; D008297:Male; D020097:Natriuretic Peptide, Brain / Q000008:administration & dosage / Q000494:pharmacology*; D012076:Renal Agents / Q000008:administration & dosage / Q000494:pharmacology*
D012076:Renal Agents; D020097:Natriuretic Peptide, Brain