Dietary sodium loading increases plasma brain natriuretic peptide levels in man

The effect of dietary sodium loading on plasma human brain natriuretic peptide-like immunoreactivity (hBNP-li) was examined in 11 normotensive subjects aged 20–23 years. Plasma hBNP-li increased significantly with increasing dietary sodium intake, with levels of 1.33 ± 0.17pmol/l on day 5 of a normal-sodium diet (24-h urinary sodium excretion of 171 ± 16mmol) and 2.04 ± 0.10pmol/l (P < 0.05, versus normal-sodium diet) on day 5 of a high-sodium diet (24-h urinary sodium excretion 503 ± 36mmol). Corresponding plasma atrial natriuretic factor levels were 5.6 ± 1.7pmol/l and 11.0 ± 2.0pmol/l (P < 0.05, versus normal-sodium diet) on the normal- and high-sodium diets, respectively. These results suggest that, in addition to atrial natriuretic factor, BNP may be a new and important natriuretic peptide which regulates sodium homeostasis in man during increased sodium intake.