AJP - Renal Physiology, Vol 261, Issue 1 70-F75, Copyright © 1991 by American Physiological Society

ARTICLES

Effects of dopamine-receptor antagonists and renal denervation on amino acid-induced hyperfiltration

R. E. Mendez, R. Lopez, G. Lopez, M. S. Marti and M. Martinez-Maldonado
Department of Medicine, University of Puerto Rico School of Medicine, San Juan.

The mechanism whereby an infusion of amino acids (AA) leads to increments in glomerular filtration rate (GFR) and renal plasma flow (RPF) is incompletely understood. Dopamine (DA) is a catecholamine in which known actions at low doses include the ability to increase both GFR and RPF. Furthermore, urinary DA excretion has been shown to be augmented after an oral protein load. We therefore studied the renal hemodynamic response to intravenous infusion of a 10% mixed AA solution in anesthetized euvolemic Wistar-Furth rats in the presence or absence of specific DA1 [Sch 23390 (SCH)] and DA2 [S-sulpiride (S-SP)] receptor antagonists. Infusion of AA in vehicle-pretreated rats resulted in a 28 +/- 8% increase in GFR and a 29 +/- 6% increase in effective ERPF over baseline values. Administration of AA in the presence of SCH also resulted in elevations in both GFR and ERPF by 23 +/- 3% and 26 +/- 6%, respectively. In contrast, when AA were given in the presence of S-SP, the rise in both GFR and ERPF was completely prevented. To examine whether the AA-induced hyperfiltration was due to DA release from renal nerves or enhanced renal tubule DA synthesis, we administered AA to rats in which the left kidney had been chronically denervated while the right kidney remained intact. Infusion of AA led to significant increments in GFR (33 +/- 4%) and ERPF (34 +/- 7%) only in the intact control kidney, whereas GFR and ERPF remained unaltered in the denervated kidney.(ABSTRACT TRUNCATED AT 250 WORDS)

This article has been cited by other articles:

				G. Luippold, M. Beilharz, and B. Muhlbauer Reduction of glomerular hyperfiltration by dopamine D2-like receptor blockade in experimental diabetes mellitus Nephrol. Dial. Transplant., July 1, 2001; 16(7): 1350 - 1356. [Abstract] [Full Text] [PDF]

				G. Luippold and B. Mühlbauer Dopamine D2 Receptors Mediate Glomerular Hyperfiltration Due To Amino Acids J. Pharmacol. Exp. Ther., September 1, 1998; 286(3): 1248 - 1252. [Abstract] [Full Text]