Suppression of plasma renin and aldosterone in stress-salt hypertension in dogs.
Plasma renin activity (PRA) and plasma aldosterone concentrations (PAC) of 12 intact chronically instrumented dogs were measured at midday after 1) 7-12 days of normal sodium intake and no behavioral stress, 2) 7-12 days of continuous saline infusion (1.34 l/day) only, and/or 3) 7-12 days of saline infusion and avoidance-conditioning sessions. The saline infusion procedure did not significantly change arterial pressure or heart rate relative to base line but was associated with a consistent decrease in PRA (-0.90 +/- 0.38 ng angiotensin I . ml-1 . h-1) and PAC (-3.6 +/- 1.1 ng/dl). The combination of saline infusion and avoidance conditioning resulted in significant elevations in arterial pressure, but, again, both PRA (-1.46 +/- 0.16 ng angiotensin I . ml-1 . h-1) and PAC (-3.7 +/- 1.1 ng/dl) were significantly decreased. These results show that high sodium intake decreased aldosterone via suppression of renin release but do not rule out a possible hypertensinogenic role for stress-induced adrenocorticotrophic hormone-sensitive corticoids.
D000450:Aldosterone / Q000097:blood*; D000818:Animals; D001362:Avoidance Learning; D002319:Cardiovascular System / Q000503:physiopathology; D004285:Dogs; D005260:Female; D006339:Heart Rate; D006973:Hypertension / Q000097:blood* / Q000209:etiology / Q000503:physiopathology; D012083:Renin / Q000097:blood*; D012965:Sodium Chloride; D013312:Stress, Physiological / Q000150:complications / Q000503:physiopathology
D012965:Sodium Chloride; D000450:Aldosterone; D012083:Renin