ISSN:
0003-276X
Keywords:
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Medicine
Notes:
An interrelationship between atrial natriuretic peptide (ANP) and the renin-angiotensin system has been established. Both of these hormonal systems are modulated by sodium balance. The role of the beta-adrenoceptor in the regulation of release of ANP is not clear. We therefore undertook a study to examine changes in atrial-specific granule number and plasma ANP level following beta-adrenoceptor blockade in rats on low and high sodium intakes. A low-sodium diet, as compared with a high-sodium diet, elevated right and left atrial-specific granule number (right atria 54.6 ± 8.7 vs. 42.3 ± 5.7; left atria 47.7 ± 7.7 vs. 30.6 ± 3.4 granules/unit area) and plasma renin activity (28 ± 3.7 vs. 5.4 ± 0.8 ng Al/ml/hr). Plasma ANP levels were lower in the low-sodium animals (98 ± 34 vs. 345 ± 38 pg/ml). When treated with the nonspecific beta-adrenoceptor blocker propranolol, the elevated plasma renin activity and atrial-specific granule number in rats on a low sodium intake were significantly less. Neither of these parameters changed in rats on a high sodium intake. Conversely, propranolol treatment resulted in lower plasma ANP levels in rats with high sodium intake. The already-suppressed plasma ANP level in rats on a low-sodium diet was unaltered with beta-adrenoceptor blockade. The results suggest that dietary sodium intake is an important determinant of the response of atrial-specific granule number and plasma ANP levels following beta-adrenoceptor blockade with propranolol.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/ar.1092280407
Permalink
