Summary
Withdrawal of captopril therapy for cardiac failure results in increments in plasma
cortisol, noradrenaline and heart rate. To determine whether these changes related
to the concomitant rise in circulating angiotensin II, we infused angiotensin II at
0.5, 2, 4 and 8 ng/kg/minute, each infusion lasting for 1 hour, in 4 patients during
maintenance captopril therapy for heart failure. A control solution of 5% dextrose
was infused over a similar time interval on a separate day. The study was performed
under metabolic balance conditions, with constant body posture and continuous haemodynamic
monitoring.
Angiotensin II induced the expected rise in arterial pressure and in plasma aldosterone.
In contrast the diurnal decline in plasma ACTH and cortisol was not altered, and no
changes in noradrenaline or heart rate were observed.
Plasma angiotensin II appears to have little or no effect on ACTH, cortisol, noradrenaline
and heart rate under the conditions of this study.
Key-Words:
Heart Failure
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Angiotensin II
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Captopril
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Cortisol
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Aldosterone
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Noradrenaline
