EFFECTS OF ISOTONIC SALINE LOADING ON RENAL TUBULAR AND NEUROGENIC DOPAMINE RELEASE IN CONSCIOUS RABBITS

1. This study was designed to investigate the effects of isotonic sali ne loading on renal tubular and neurogenic dopamine (DA) in conscious rabbits. 2. Isotonic saline loading did not affect mean arterial press ure, heart rate or renal blood flow but markedly increased urine volum e, sodium excretion and DA excretion. 3. Renal DA spillover was not af fected by venous emptying, while renal noradrenaline (NA) spillover te nded to decrease during saline loading. The ratio of % renal DA spillo ver to % renal NA spillover increased to 2.3 +/- .0.6 (P < 0.05) 3 h a fter saline loading. 4. Isotonic saline loading increased renal tubula r DA production but had little effect on neurogenic DA release.