This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Montanari, A. Articles by Dall’Aglio, P. Search for Related Content PubMed PubMed Citation Articles by Montanari, A. Articles by Dall’Aglio, P.

(Hypertension. 1998;31:277.)
© 1998 American Heart Association, Inc.

Scientific Contributions

Dopamine-2 Receptor Blockade Potentiates the Renal Effects of Nitric Oxide Inhibition in Humans

Alberto Montanari; Enrico Tateo; Elena Fasoli; Anna Donatini; Barbara Cimolato; Patrizia Perinotto; Pierpaolo Dall’Aglio

From the Istituto di Patologia Medica (A.M., E.T., A.D., B.C., P.P., P.D.’A) and Istituto di Semeiotica Medica (E.F.) University of Parma, Parma, Italy

Correspondence to Alberto Montanari, MD, Istituto di Patologia Medica, Via Gramsci 14, I-43100 Parma, Italy. E-mail:montalbr{at}ipruniv.cce.unipr.it

In eight young healthy subjects on a 240 mM Na diet mean arterial pressure (MAP), renal hemodynamics and renal handling of Na and exogenous Li were measured at baseline and during acute nitric oxide (NO) inhibition with 90-minute infusion of 3.0µg/kg.min^-1 of N^G-L-arginine methyl ester (L-NAME). The same experiment was repeated with infusion of 50µg/kg.min^-1 of DA₂ receptor blocker L-Sulpiride (L-SULP) alone and, finally, with simultaneous infusion of both L-NAME and L-SULP. L-SULP alone did not elicit any effect. L-NAME alone produced no changes in MAP from 0 to 45 minutes (P₁) and a 6.6% increase at 45 to 90 minutes (P2) of infusion. Effective renal plasma flow (ERPF, PAH clearance) and glomerular filtration rate (GFR, inulin clearance) declined by 10.2% and 7.6%, respectively, in P₁ and by 15.3% and 11.5% in P₂. Filtration Fraction (FF) rose by 4.2% in P₂. Calculated renal vascular resistance (RVR) increased by 13.0% to 25.6%. Fractional excretion of Na (FENa) and Li (FELi) fell by 20.0% and by 16.0%, respectively, in P₁ and by 40.0% and 25.1% in P₂. All these variations, except for MAP and GFR, were significantly greater during coinfusion of L-NAME and L-SULP. ERPF declined by 17.8% to 33.7%, FENa by 26.7% to 53.3%, FELi by 13.8% to 34.8%, while RVR rose by 22.5% to 59.1% and FF by 10.1% to 29.3%. The present data confirm that NO blockade with low-dose systemic infusion of L-NAME produces renal vasoconstriction, reduced GFR with slight increase in FF, and enhanced tubular Li, and Na reabsorption. Since increase in RVR and FF and decrease in FENa and FELi are markedly potentiated by the simultaneous infusion of DA₂ blocker L-SULP, which exerts no effects by itself, we suggest that DA interactions between DA system at the level of DA₂ receptors and basal NO production play a physiological role in the regulation of renal function in humans.

Key Words: DA2 receptor • L-SULP • L-NAME • human • kidney • nitric oxide • hemodynamics

Abbreviations: D-SULP = D-Sulpiride or (D)-Sulpiride or (+) Sulpiride • ERPF = effective renal plasma flow • FF = filtration fraction • GFR = glomerular filtration rate • L-NAME = N^G-nitro-L-arginine methyl ester • L-NMMA = N^G-monomethyl-L-arginine • L-NNA = N^G-nitro-L-arginine • L-SULP = L-Sulpiride or (S)-Sulpiride or (-) Sulpiride • MAP = mean arterial pressure • NE = norepinephrine • NO = nitric oxide • NO_x = NO₂ plus NO₃ • PRL = prolactin • RBF = renal blood flow • RSNA = renal sympathetic nerve activity • RVR = renal vascular resistance • SNS = sympathetic nervous system • SULP = Sulpiride

This article has been cited by other articles:

				M. Liang and F. G. Knox Production and functional roles of nitric oxide in the proximal tubule Am J Physiol Regulatory Integrative Comp Physiol, May 1, 2000; 278(5): R1117 - R1124. [Abstract] [Full Text] [PDF]