Flight influence on the plasma level of renin-angiotensin-aldosterone system and atrial natriuretic peptide.

Plasma levels of the renin-angiotensin-aldosterone system (RAAS) and atrial natriuretic peptide (ANP) were studied in healthy male pilots, and in a ground crew control group. Plasma concentrations of angiotensin I (A I), angiotensin II (A II) and aldosterone (Aldo) were measured in the pilots before and after flight by radioimmunoassay. Results showed that the plasma concentrations of A I, A II, and Aldo were much higher after flight than before flight, and were different from samples taken from the control group (p less than 0.001). On the other hand, the ANP levels in the pilot group did not differ significantly from the control group, before or after flight. There was no significant difference of the four hormones within the control group over the course of the study. This suggests that the development of hypertension in pilots may relate to the reaction of the RAAS.