| Abstract: | Atrial myocytes produce natriuretic and vasodilating peptides. Animal experiments have shown that atrial natriuretic peptide (ANP) is released after stretching the atria and drained via the coronary vein effluent. In this study ANP-plasma levels were measured in 14 patients. Blood samples were simultaneously collected from the right atrial cavum and from an antecubital vein. In the right atrial samples, ANP-plasma concentrations were significantly higher than in samples drawn from a peripheral vein (140.3 +/- 114.8 pg/ml vs 96.9 +/- 69.2 pg/ml; p less than 0.05), but a significant linear correlation was found between both values (r = 0.88; p less than 0.001). In patients with elevated atrial pressures significantly higher ANP-levels could be detected than in patients with normal atrial pressures (204 +/- 115 pg/ml vs 55.3 +/- 18.5 pg/ml; p less than 0.05). Mean right atrial pressure correlated to ANP-levels in right atrial blood (r = 0.79; p less than 0.001) as well as to ANP-levels in peripheral blood (r = 0.68; p less than 0.01). These results indicate that higher ANP plasma levels can be measured in samples drawn from a site close to ANP production. On the other hand, atrial pressure might influence the amount of circulating ANP. |
