Nitric oxide and the role of blood pressure variability to the kidney.
Blood pressure variability is buffered by at least two mechanisms: the arterial baroreceptor reflex and nitric oxide (NO). Only recently is the importance of blood pressure variations on cardiovascular control being investigated. Here we report of a study performed in conscious dogs, in which renovascular hypertension was induced. Reduction of renal arterial pressure (RAP) to 85 mmHg for 24 h elicited profound hypertension by 60 mmHg (vs. control: 110 +/- 3 mmHg; P < 0.01). This was accompanied by reduced volume and sodium excretion (-48% of control, P < 0.01 and -80% of control, P < 0.01, respectively) and augmented renin release by more than two-fold (P < 0.01). This intervention was compared with a protocol in which RAP was reduced to the same mean value, however, RAP oscillated by +/-10 mmHg at 0.1 Hz. This manoeuvre led to a transient increase in NO3 excretion in urine (P < 0.01), blunted antidiuresis (-14% of control) as well as antinatriuresis (-40% of control) and attenuated the increased renin release by 30% (P < 0.05). In consequence, the magnitude of blood pressure increase was only half as high as that observed during static reduction of RAP (P < 0.01). It is concluded that blood pressure oscillations to the kidney have a profound influence on water and electrolyte balance and on renin release, which alleviates the onset of Goldblatt hypertension.
Nafz
B
B
Johannes-Müller-Institut für Physiologie, Humboldt Universität (Charité), Berlin, Germany.
Seeliger
E
E
Persson
P B
PB
D000818:Animals; D001794:Blood Pressure / Q000502:physiology*; D004285:Dogs; D006977:Hypertension, Renal / Q000503:physiopathology; D007668:Kidney / Q000098:blood supply*; D009566:Nitrates / Q000652:urine; D009569:Nitric Oxide / Q000378:metabolism*; D011188:Potassium / Q000652:urine; D012079:Renal Circulation / Q000502:physiology; D012083:Renin / Q000378:metabolism; D012964:Sodium / Q000652:urine
D009566:Nitrates; D009569:Nitric Oxide; D012964:Sodium; D012083:Renin; D011188:Potassium