[Study of the expression and role of adrenomedullin and adrenomedullin receptor in patients with chronic obstructive pulmonary disease].

OBJECTIVE

To investigate the expression and role of adrenomedullin (ADM) and adrenomedullin receptor (ADMR) in patients with chronic obstructive pulmonary disease (COPD).

METHODS

The first study included 9 COPD patients (group I) and 7 control patients (group II) who had underwent pulmonary lobe resection. Small pulmonary artery remodeling was observed with morphometric analysis. The expressions of ADM and ADMR mRNA in lung tissue were examined by hybridization in situ. The second study recruited 22 patients with COPD. Cardiac catheterization was performed to monitor the changes of hemodynamic parameters and the subjects were divided into two groups according to the mean pulmonary artery pressure (mPAP): patients without pulmonary hypertension (PH, group A, n = 10) and patients with PH (group B, n = 12). The levels of pulmonary arterial plasma ADM were measured by radioimmunoassay. Arterial blood gas was also measured.

RESULTS

(1) In patients underwent pulmonary lobe resection: (1) Morphometry studies showed that the ratio of vascular wall thickness to external diameter (MT%) and ratio of vascular wall area to total area (MA%) increased in group I (P < 0.01); (2) Hybridization in situ showed that ADM/ADMR mRNA expressions were significantly higher in pulmonary artery walls of group I as compared with group II (P < 0.01). (2) In COPD patients without pulmonary lobe resection, the plasma ADM level of group B was significantly higher than that of group A (P < 0.05), and the plasma ADM level had a significantly positive correlation with mPAP and pulmonary vascular resistance (PVR), but a negative correlation with PaO(2).

CONCLUSION

ADM may play an important protective role as a local autocrine/paracrine factor in the development of COPD and PH.