[Synthesis and release of pulmonary tissue adrenomedullin on hypoxic pulmonary hypertension in rats and its significance].
OBJECTIVE
To investigate the synthesis and release of adrenomedullin (AM) of lung tissue in rats on hypoxic pulmonary hypertension (HPH) and study its mechanism and significance in the pathogenesis process of HPH.


METHODS
54 Wistar rats were divided into hypoxia 10 d (n = 12), 20 d (n = 12), 30 d (n = 12) groups and control group (n = 18). The rats of hypoxia groups were exposed to chronic hypobaric hypoxia environment at high 5 km to establish HPH models. The expression of pulmonary cell AM protein, the content of plasma AM and bronchial alveolar lavage fluid (BALF) AM were determined by optical microscopy, immunohistochemistry and radio-immunoassay.


RESULTS
AM was widely distributed in lung tissue. There was positive of AM in intraplasma of vascular endothelial cells (EC), vascular and bronchial smooth muscular cells (SMC), bronchial epithelial cells, macrophages (M phi) and type II alveolar epithelial cells in every groups. After hypoxia, the expression of AM in above cells, especially EC, SMC and M phi, increased more than control group. Plasma AM contents of hypoxia groups were higher than control group(P < 0.01). 20 d after hypoxia, the AM content was twice as control group. At 10 d to 20 d after hypoxia, BALF AM content was increased more than control group (P < 0.01). But at 30 d the content was decreased near to normal.


CONCLUSIONS
Hypoxia is effective in promoting AM synthesis and release in pulmonary tissue and suggestes that AM as a peptide plays an important regulating role on pulmonary circulation, exchange of air and pulmonary vascular structural remodeling in the pathophysiological process of HPH.
Wang
S
S
Department of Pathology, General Hospital of Chengdu Command, Chengdu 610083, China.
Yu
Z
Z
Liu
K
K
D053607:Adrenomedullin; D000532:Altitude Sickness / Q000097:blood / Q000378:metabolism* / Q000503:physiopathology; D000818:Animals; D001992:Bronchoalveolar Lavage Fluid; D004195:Disease Models, Animal; D006976:Hypertension, Pulmonary / Q000097:blood / Q000378:metabolism* / Q000503:physiopathology; D008168:Lung / Q000378:metabolism* / Q000503:physiopathology; D008297:Male; D010455:Peptides / Q000097:blood / Q000378:metabolism*; D011669:Pulmonary Wedge Pressure; D051381:Rats; D017208:Rats, Wistar
D010455:Peptides; D053607:Adrenomedullin