1. The influence of deoxycorticosterone acetate (DOCA)–salt hypertension on brain atrial natriuretic factor (ANF) in rats was investigated to elucidate the role of central ANF in a renin-independent model of experimental hypertension.
2. Sprague-Dawley rats were subjected to uninephrectomy and given either tap water or saline [1% (w/v) NaCl] to drink plus weekly injections of either saline or DOCA (25 mg/kg, subcutaneously). After 32 days, the rats were decapitated and 18 different brain nuclei were removed by a micropunch technique.
3. The systolic blood pressure of the DOCA-salt rats was significantly higher than that of control rats [154 ± 3 mmHg vs 104 ± 2 mmHg (20.53 ± 0.40 kPa vs 13.86 ± 0.27 kPa), P < 0.001].
4. Plasma ANF levels were significantly (P < 0.01) higher in DOCA-salt hypertensive rats compared with control rats.
5. In DOCA-salt hypertensive rats, the ANF content was increased in the organum vasculosum of the lamina terminalis (31.4 ± 2.1 vs 22.1 ± 2.5 pg/mg of protein, P < 0.05), the subfornical organ (32.5 ± 5.0 vs 24.2 ± 2.4 pg/mg of protein, P < 0.05), the medial amygdaloid nucleus (49.0 ± 6.4 vs 34.0 ± 2.0 pg/mg of protein, P < 0.05) and the locus coeruleus (86.9 ± 4.1 vs 64.4 ± 4.2 pg/mg of protein, P < 0.01) compared with control rats. The ANF content of 14 other brain areas investigated did not alter after treatment.
6. Our data demonstrate that the development of DOCA-salt hypertension in rats is associated with changes in the ANF content of specific brain areas, especially the locus coeruleus, and is consistent with an important pathophysiological role of this pontine area in the development of DOCA-salt hypertension.
Blood pressure and renal responses to synthetic rat atrial natriuretic factor in deoxycorticosterone acetate-salt hypertension.