ORIGINAL ARTICLES   

Minerva Pneumologica 2007 June;46(2):53-8

Copyright © 2007 EDIZIONI MINERVA MEDICA

language: English

The effects of simulated weightlessness on pulmonary artery reactivity and its mechanism

Junfeng W., Changting L., Congjun H., Delong W.

Department of Respiration General Hospital of PLA, Beijing, China

Aim. The effects of simulated weightlessness on pulmonary artery responsiveness and its mechanisms are still unknown.
Methods. A rat tail suspension model (14 days) was used to simulate weightlessness; the vascular bathing technique was used to measure the contractile responses of rat pulmonary artery rings to phenylephrine (PE) and KCL, dilatory responses to acetylcholine (Ach) and contractile response to PE in the presence of the nitric oxide synthase retardant L-NAME. eNOS protein expression and NO content in pulmonary tissues were detected by Western blot analysis and the nitrate enzyme-reduction method, respectively.
Results. After simulated weightlessness for 14 days, pulmonary artery contractile response to PE and KCL decreased significantly, dilatory response to Ach increased significantly and L-NAME abolished the differential responses to PE in both the tail-suspended and control groups. The expression of eNOS and the NO content in the pulmonary artery after simulated weightlessness both increased significantly.
Conclusion. Contractile responsiveness is attenuated in rat pulmonary arteries after simulated weightlessness owing to increased NO expression on the vascular endothelium; the NO synthase retardant L-NAME can recover pulmonary artery contractile responsiveness.