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.