Intrarenal effects of [ XXXX -(Ile3-Val5)] angiotensin II in the conscious @entity235 .

@entity1 @entity1369 @entity235 @entity535 @entity1372 @entity71090 @entity35
Amphibian skin has functional characteristics of epithelium in the @entity1 distal nephron and plays an important role in @entity1372 and water metabolism in these animals. A peptide extracted from the skin of the Australian frog Crinia georgiana has been purified, has been determined to have the @entity535 sequence of [ @entity71090 -(Ile3-Val5)]angiotensin II, and recently has been synthesized. We studied the renal effect of synthetic frog skin angiotensin II (FSAII) infused via the renal artery in doses that were confined to the kidney. FSAII was infused intrarenally at 0.2, 2, and 4 pmol/kg.min in uninephrectomized conscious @entity235 (n = 5) in metabolic balance at a @entity1372 intake of 80 meq/day. FSAII was confined to the kidney, as demonstrated by the absence of any systemic pressor response and/or any increase in plasma @entity1369 concentrations during intrarenal FSAII infusion at @entity35 of 0.2 and 2 pmol/kg.min. At 4 pmol/kg.min, FSAII traversed the kidney in amounts sufficient to stimulate @entity1369 secretion (P less than 0.05). All three doses of FSAII caused significant antidiuresis and antinatriuresis, and decreased fractional excretion of @entity1372 . There were no changes in the glomerular filtration rate (GFR) or renal plasma flow (RPF) during FSAII infusion at 0.2 and 2 pmol/kg.min. At 4 pmol/kg.min, FSAII engendered a significant decrease in GFR and RPF, while the filtration fraction increased. There were no significant changes in arterial blood pressure at any dose of FSAII. When confined to the kidney, FSAII caused antidiuresis and anti-natriuresis in the absence of a change in GFR and RPF. These results provide evidence that angiotensin acts directly at the renal tubular level to alter renal function.
