Atrial natriuretic hormone is not elevated during dopamine induced natriuresis

To evaluate the possibility that atrial natriuretic hormone (ANH) is involved in dopamine induced natriuresis and diuresis, we studied five normal male volunteers. Each was studied on two occasions. During the first two hours of each study, normal saline, 25 ml/hr, was infused. During the second two hours either normal saline, 25 ml/hr, or dopamine, 4 [mu]g/kg/min, in normal saline, was infused. Dopamine infusion caused prominent and significant natriuresis and diuresis but plasma levels of immunoreactive ANH levels did not change. We conclude that the ANH is not involved in dopamine induced natriuresis and that dopaminergic stimulation is not responsible for ANH secretion.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/26700/1/0000248.pd

Plasma levels of immunoreactive atrial natriuretic hormone in patients with diabetes mellitus

In order to determine whether atrial natriuretic hormone (ANH) secretion is altered in diabetic patients with autonomic neuropathy, plasma immunoreactive ANH (IR-ANH) levels were measured in 23 patients with insulin-dependent diabetes mellitus, 12 of whom had definite cardiac autonomic neuropathy determined by noninvasive maneuvers. Levels were also measured in 31 healthy control subjects. Whereas only one of the 11 diabetics without cardiac autonomic neuropathy had elevated IR-ANH levels, four of the 12 diabetics with cardiac autonomic neuropathy had elevated IR-ANH levels (P = 0.03 compared to control subjects). 24-h urinary sodium excetion was not different among the groups. There was no significant correlation between IR-ANH levels and diabetes control and any of the parameters of autonomic nervous system activity nor between IR-ANH levels and plasma norepinephrine or epinephrine levels. Furthermore, no relationship was observed in the diabetic subjects between IR-ANH levels and left ventricular ejection fraction determined by radionuclide ventriculography. Thus, elevated IR-ANH levels occur with greater frequency in diabetic patients with autonomic neuropathy. These elevations do not appear to be due to alterations in dietary sodium intake or left ventricular dysfunction.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25997/1/0000063.pd

Atrial natriuretic hormone secretion in patients with renal failure

To study the effects of volume overload and renal failure on plasma levels of immunoreactive atrial natriuretic hormone (IR-ANH), we measured levels of this hormone in normal subjects, in patients with advanced chronic renal failure (CRF) with and without clinically evident volume overload, and in patients with end-stage renal disease (ESRD) treated with chronic hemodialysis. The levels were 13 +/- 2 pmol/l in normal volunteers, 77 +/- 24 pmol/lin patients with CRF without volume overload, and 219 +/- 50 pmol/l in patients with CRF and clinically evident volume overload (analysis of variance, p Volume overload appears to be the most important stimulatory factor for ANH secretion in renal failure patients but other mechanisms, especially a decrease in metabolic clearance, may also contribute to elevated plasma levels. The increased secretion of ANH in patients with renal failure may be an important adaptive response to volume overload and hypertension.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/26573/1/0000112.pd

Plasma levels of immunoreactive atrial natriuretic factor increase during supraventricular tachycardia

A significant diuretic and natriuretic response occurs during paroxysmal supraventricular tachycardia (SVT). Although the diuresis may be secondary to suppression of vasopressin secretion, the etiology of the natriuresis remains unexplained. To determine if atrial natriuretic factor (ANF) could contribute to the polyuric response during SVT, 10 patients were studied: five during spontaneous SVT and five during simulated SVT produced by rapid simultaneous atrial and ventricular pacing. Plasma immunoreactive ANF (IR-ANF) levels measured by radioimmunoassay were obtained at baseline (before and/or 24 to 48 hours after SVT) and after at least 15 minutes of SVT in all patients. During spontaneous and simulated SVT, IR-ANF was significantly elevated (mean +/- SE; 275 +/- 68 pmol/L) compared to baseline (28 +/- 7 pmol/L; P = 0.0036). Similar increases in IR-ANF were noted during both simulated and spontaneous SVT. To determine if this IR-ANF release was related to the increase in heart rate or the rise in right atrial pressure during SVT, IR-ANF levels were also measured in five patients with sinus tachycardia and in six patients with congestive heart failure, IR-ANF was significantly related to right atrial pressure (r = 0.93; P = 0.0009) but not to heart rate (r = 0.46). Thus, IR-ANF is elevated during SVT and may contribute to the natriuretic response. The stimulus to IR-ANF secretion during SVT appears to be related to the rise in right atrial pressure rather than to the increase in heart rate.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/26001/1/0000067.pd