Plasma atrial natriuretic peptide in DOCA‐NaCl‐treated rats

In order to assess the possible role of atrial natriuretic peptide (ANP) in the development of deoxycorticosterone (DOCA)‐NaCl‐induced hypertension, plasma immunoreactive ANP concentration was compared with sodium balance and blood pressure in NaCl‐ or DOCA‐NaCI‐treated rats. Both NaCl‐and DOCA‐NaCl‐loading increased plasma ANP levels (to 86 ± 8.1 and 105 ± 12 pg ml‐1 respectively; 47±6.7–60±4.6 pg ml‐1 in controls), which were correlated to sodium intake and excretion. In DOCA‐NaCI‐treated rats, the highest ANP levels (105 ± 12 pg ml‐1) were found 4 weeks after the beginning of DOCA‐NaCl treatments. Along with the development of DOCA‐NaCl hypertension in 1‐kidney‐DOCA‐NaCl‐treated rats, however, plasma ANP concentration did not rise further. We conclude that secretion of ANP into the circulation is increased during DOCA‐NaCl treatment. Elevated blood pressure does not stimulate ANP release in DOCA‐NaCI‐treated rats further.