Decreases Plasma Atrial Natriuretic Peptide in Patients With Salt-sensitive Essential Hypertension and Increase After Benazepril Therapy / 中华高血压杂志

ABSTRACT

Objective To study the role of atrial natriuretic peptide (ANP) and renin-angiotensin-aldosterone system (RAAS) in the pathogenesis of salt-sensitive (SS) hypertension and mechanism of the hypotensive effect of benazepril and ANP in patients with SS essential hypertension. Methods Sixty-four patients with essential hypertension were divided into SS (n=30) and non-salt-sensitive (NSS, n=34) groups by modified Sulliran's method. Plasma ANP, angiotensin Ⅱ (AⅡ) and aldosterone (ALD) were determined before and during the period of salt loading test. Thirty healthy subjects as controls were also enrolled. A self-comparative study of benazepril with the placebo was performed in SS group. Before and after the placebo and benazepril therapy, blood pressure (BP) and plasma ANP were determined. Results (1)Basal plasma ANP level in the SS group was significantly lower than that in the NSS group. Basal plasma ANP level in the NSS group was also significantly lower than that in the control group [(110.28±15.40) pmol/L vs NSS (145.52±26.53) pmol/L and control (197.74±26.20) pmol/L]. Plasma ANP in both SS and NSS groups [(133.56±34.03) pmol/L and (169.20±35.91) pmol/L respectively, both P<0.05 vs control]. Percentage of increase of plasma ANP in SS and NSS groups was of no difference (P>0.05) . (2) No significant difference of basal plasma AⅡ and ALD levels were found between SS and NSS groups (P>0.05). There were no significant changes of plasma AⅡ and ALD during salt loading in both SS and NSS groups ( both P>0.05). (3) After the benazepril treatment, plasma ANP was increased significantly [(146.74±31.86) pmol/L , P<0.01]; both systolic and diastolic BP were reduced significantly in SS group. (4) Basal plasma ANP level was negatively correlated with the magnitude of increase of mean arterial pressure (MAP) by salt loading (b=-0.06, P<0.05). Conclusion Deficiency of circulating endogenous ANP may play an important role in the pathogenesis of SS hypertension. Benazepril could reduce BP and increase plasma ANP significantly in patients with SS hypertension.