The effects of physiological shifts in plasma atrial natriuretic factor (ANF) concentrations on angiotensin II/aldosterone relationships during changes in sodium status were assessed in 6 conscious beagle dogs. Incremental infusions of angiotensin II (3, 9 and 27ng/kg/min) were administered on three occasions. The animals were studied in sodium replete and deplete states and on a third occasion, again while sodium deplete, with a background constant low-dose infusion of ANF (1.5pmol/kg/min) sufficient to enhance the low endogenous plasma ANF values observed in sodium depletion to match those observed in the sodium replete state. Sodium depletion caused a leftward shift and steepened the slope of the relationship between achieved arterial angiotensin II concentrations and the plasma aldosterone response. This effect was significantly attenuated (approximately 50% by the low dose ANF infusions which tended to flatten the slope of the angiotensin llialdosterone curve (ns) and shifted it significantly to the right (p <0.05). These data suggest subtle shifts in endogenous levels of plasma ANF, accompanying changes in sodium status, are a major contributor to the associated alterations in angiotensin Waldosterone relationships. Low dose ANF also significantly reduced the effect of angiotensin II on arterial pressures but did not alter natriuresis.
- Angiotensin-aldosterone relationship
- Atrial natriuretic factor
- Sodium status
ASJC Scopus subject areas
- Internal Medicine