Postoperative change of atrial natriuretic peptide and renin-angiotensin-aldosterone system after pulmonary resection for lung cancer

We studied postoperative changes in atrial natriuretic peptide (ANP), renin-angiotensinaldosterone system and angiotensin converting enzyme (ACE) activity after pulmonary resection for lung cancer. ANP increased significantly immediately after operation. Also plasma renin activity (PRA) and angiotensin I (ANG I) increased significantly after operation, but angiotensin II (ANG II) did not increase. Aldosterone (ALD) increased transitorily immediately after operation but thereafter decreased. ACE activity decreased significantly due to reduction of pulmonary vascular bed by lung resection. We estimated that it was the cause of decrease of ALD. After pulmonary resection two contrary endocrine environments existed : ANP increased due to atrial loading whereas PRA increased too. Therefore body fluid should be managed under the dry side and use of catecholamine for support of cardiac function and maintaining renal perfusion should be considered after pulmonary resection.