The Effect of Atrial Natriuretic Peptide Infusion on Renal Haemodynamics and Plasma Lipoproteins in Puromycin Aminonucleoside Nephrosis in Rats

Abstract

1. The effect of continuous intravenous administration of 1 microgram/h atrial natriuretic peptide (ANP) for 4 days was studied in normal male Sprague-Dawley rats and rats made nephrotic with puromycin aminonucleoside (PA). 2. ANP infusion significantly increased urinary sodium and potassium excretion by 3 days of infusion in control rats but not in PA-treated rats. ANP infusion significantly increased glomerular filtration rate in PA-treated rats, while effective renal plasma flow was similarly decreased compared with non-infused nephrotic rats. 3. Plasma high density lipoproteins (HDL) were significantly decreased and low density lipoproteins (LDL) were increased in PA-treated rats that received ANP; HDL were increased in normal rats infused with ANP. 4. Competitive binding studies demonstrated a lower density of specific ANP receptors in glomerular membranes from rats injected with PA, while binding affinity was unchanged. 5. Infusion with exogenous ANP did not promote natriuresis in PA nephrosis despite an enhancement of glomerular filtration rate (GFR), thus suggesting that sodium retention in this model is due to a post-glomerular defect. Plasma lipoprotein composition in both normal and nephrotic rats may be affected by ANP.

Atrial natriuretic peptide in normal and pre-eclamptic human pregnancy

“…87,92,93 This reduction of ERPF in late pregnancy with no change in GFR is similar to the physiological renal haemodynamic adaptation to pregnancy in the third trimester, when ERPF is reduced but GFR is maintained at a time when pANP is known to be elevated. 87,92,93 This reduction of ERPF in late pregnancy with no change in GFR is similar to the physiological renal haemodynamic adaptation to pregnancy in the third trimester, when ERPF is reduced but GFR is maintained at a time when pANP is known to be elevated.…”

Is edema in minimal change disease of childhood really hypovolemic?

“…Therefore, hypovolemia and stimulation of the renin-aldosterone axis are not the primary factors governing sodium retention in nephrotic syndrome. Plasma and blood volume were normal or slightly elevated in several experimental models of nephrotic syndrome [16]. Plasma and blood volume are normal in 84%, low in 2%, and high in 14% of nephrotic patients with edema [17].…”

The pathophysiology of edema formation in the nephrotic syndrome

“…47 Other groups have also noted diminished natriuresis in response to ANP infusion in PAN nephrotic rats. [48][49][50] Rats with nephrosis due to Heymann nephritis and PAN have been shown to have similar levels of ANP at baseline and after volume expansion as controls, but had diminished diuresis in response to volume expansion vs. controls. 50,51 In a study of nephrotic rats, ANP infusion resulted in a blunted natriuresis and diuresis compared with controls.…”