Effects of SAP Aa D on plasma (A), atria (B) and urine (C) ANP. Rats received an oral loading of physiological solution (0.9 % NaCl, 4 ml/100 g body weight) in the absence (control) and presence of 50 mg/kg of SAPAa D). At 90 min after SAPAa D administration, a sample of blood and urine were collected, rats were sacrificed and the atria were removed for ANP measurement. Plasma (n = 6), pooled left and right atria (n = 6) and urine ANP (n = 7) were measured by RIA. Atria ANP were normalized to protein concentration and reported in micrograms per milligram of protein. Data are represented as means ± SEM. ANP in control: Plasma and atria (n = 12) and urine (n = 7). **p < 0.01 compared with the control group, unpaired Student’s t-test.