title: Significance of renal vasodilation after administration of atrial natriuretic factor in the conscious dog.
abstract: The contribution of alterations in renal hemodynamics to the diuretic and natriuretic actions of atrial natriuretic factor (ANF) was studied in chronically instrumented conscious dogs. Injection of ANF-(99-119), 10 micrograms/kg, had no effect on mean arterial pressure, heart rate, renal blood flow, or calculated renal vascular resistance; However, it increased urine flow rate (86 +/- 20%) and sodium (118 +/- 24%) and potassium (35 +/- 22%) excretion (p less than 0.05). In contrast, ANF-(99-122), 10 micrograms/kg, significantly increased renal blood flow (26 +/- 4.5%), reduced renal vascular resistance (24 +/- 2.9%) and arterial pressure (5.5 +/- 1.9%), and markedly increased urine flow rate (198 +/- 34%) and sodium (206 +/- 32%) and potassium (75 +/- 27%) excretion (p less than 0.05), being almost twice as effective in the first 10 minutes as was ANF-(99-119) infusion. During a brief infusion, ANF-(99-122) (10 micrograms/kg/min for 4 minutes) increased renal blood flow (24 +/- 2.7%), heart rate (18 +/- 5.7%), urine flow rate (199 +/- 25%), and sodium (290 +/- 81%) and potassium (104 +/- 17%) excretion. Injection of radioactive microspheres (15 or 9 micron) to measure intrarenal distribution of blood flow during the steady state increase in renal blood flow indicated that ANF-(99-122) infusion preferentially increased outer cortical blood flow. Blood flow in the four zones of the kidney cortex (Zone 1, outer, and Zone 4, inner) increased 96 +/- 25% (Zone 1), 199 +/- 87% (Zone 2), 139 +/- 47% (Zone 3), p less than 0.05, and 25 +/- 28% (Zone 4, p = NS).(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Physiology, New York Medical College, Valhalla 10595.
authors.forename: T H
authors.initials: TH
authors.lastname: Hintze
mesh_terms: D000818:Animals; D009320:Atrial Natriuretic Factor / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D003243:Consciousness; D004231:Diuresis / Q000187:drug effects; D004285:Dogs; D005260:Female; D009318:Natriuresis / Q000187:drug effects; D010446:Peptide Fragments; D012079:Renal Circulation / Q000187:drug effects*; D014655:Vascular Resistance / Q000187:drug effects; D014664:Vasodilation / Q000187:drug effects*
chemical_list: D010446:Peptide Fragments; D009320:Atrial Natriuretic Factor