Effect of high altitude hypoxia on changes of plasma CNP, ET and CGRP contents in healthy young males

Objective: To explore the changes of plasma CNP, ET and (CGR contents in healthy young males with exposure to high altitude hypoxia. Methods: Plasma CNP, ET and CGRP contents were measured with RIA in 50 healthy young males at the altitude of 1000 m (as control), 2260 m (medium altitude) and 3780 m (high altitude for 1d, 5d and 15d) successively. Results: 1) Plasma CNP contents increased gradually as the altitude rose (at high altitude for 15d vs all other 4 settings, P<0.01). 2)Plasma ET contents were significantly lower at high altitude for 5d than those at medium altitude, P<0.01. However, prolonged stay at high altitude for 15d would significantly increase the plasma ET contents (vs all other 4 settings, P<0.01). 3)Plasma CGRP contents reached peak at medium altitude (vs medium altitude, P<0.01). 4)Plasma ET contents were positively correlated with CNP contents (r=0.470, P<0.01) but negatively correlated with CGRP contents (r = - 0.425, P<0.05). Conclusion: ET, CGRP and CNP participate in the physiologic regulation of pulmonary circulation under hypoxia. CGRP, a strong vaso dilator, modulates pulmonary vascular dilatation at the early stage of hypoxia. After prolonged exposure to high altitude hypoxia ET and CNP contents increase significantly. (authors)