Expression of adrenomedullin and its receptor in lungs of rats with hypoxic pulmonary hypertension.
OBJECTIVE
To investigate the role of adrenomedullin (AM) in the development of hypoxic pulmonary hypertension (HPH), and to assess the expression of AM and adrenomedullin receptor (AMR) in the lungs of rats with HPH.


METHODS
We exposed 10 rats to normobaric hypoxic conditions for 3 weeks to establish rat model of pulmonary hypertension; and 10 other rats were used as normoxic controls. Mean pulmonary arterial pressure (mPAP) was measured by a right cardiac catheterization. The thickness of pulmonary arterioles was measured by a computerized image analyzer. We used the reverse transcription-polymerase chain reaction (RT-PCR) to assess the change of expression of AM and AMR in lung of HPH rat model.


RESULTS
Compared with the control group, hypoxic rats developed remarkable pulmonary hypertension, increment in the thickness of pulmonary arterioles and right ventricular hypertrophy (P < 0.01). Chronic hypoxia elicited a considerable increment in expression of AM and AMR in the lungs of rats, and the ratio of AM/beta-actin and AMR/beta-actin in lungs of rats treated with hypoxia were significantly higher (P < 0.01).


CONCLUSIONS
The AM plays an important role in regulating pulmonary vascular tone and can ameliorate the development of hypoxic pulmonary hypertension in rats.
Cheng
Deyun
D
Department of Internal Medicine, West China Hospital, Sichuan University, Chengdu 610041, China.
Tian
Wei
W
Chen
Wenbin
W
Xiao
Xinrong
X
D053607:Adrenomedullin; D000818:Animals; D001160:Arterioles / Q000473:pathology; D015870:Gene Expression; D006976:Hypertension, Pulmonary / Q000378:metabolism* / Q000473:pathology; D017380:Hypertrophy, Right Ventricular / Q000209:etiology; D000860:Hypoxia / Q000378:metabolism* / Q000473:pathology; D008168:Lung / Q000378:metabolism*; D008297:Male; D010455:Peptides / Q000235:genetics*; D051381:Rats; D017208:Rats, Wistar; D058265:Receptors, Adrenomedullin; D018000:Receptors, Peptide / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction
D010455:Peptides; D058265:Receptors, Adrenomedullin; D018000:Receptors, Peptide; D053607:Adrenomedullin