[Alterations of intermedin and its receptor system in oleic acid-induced acute lung injury of rats].
OBJECTIVE
To investigate the changes of pulmonary IMD and its receptor system-calcitonin receptor-like receptor (CL) and receptor activity modifying proteins (RAMPs) mRNA in acute lung injury(ALI) induced by oleic acid of rats.


METHODS
Contents of IMD in plasma and lung homogenates were measured by radioimmunoassay(RIA). The lung mRNA of IMD, CL and RAMPs was determined by semi-quantitative RT-PCR.


RESULTS
Compared with control group, in ALI group, the contents of IMD1-53 in plasma and lung homogenates were decreased by 20.8% and 74.5% (all P < 0.05) , respectively. Furthermore , it was found that the levels of IMD, CL, RAMP1 and RAMP2 mRNA in lung were decreased by 30%, 38%, 26% and 37.9% (all P < 0. 05) , respectively. The levels of CL , RAMP1 or RAMP2 mRNA were positively correlated with down-regulations of IMD mRNA in ALI. However, compared with control group, the maximum binding capacity of IMD1-53 to plasma membranes was significantly increased in ALI group, and the affinity of IMD1-53 for its receptor almost had no change.


CONCLUSIONS
The amount of IMD 1-53 is down-regulated and IMD receptor system also down-regulated in Oliec acid induced ALI of rats. These changes suggest that IMD and its receptor system probably are involved in the development of ALI.
Yu
Xiao-min
XM
Department of Geriatric Medicine, Peking University First Hospital, Beijing 100034, China.
Liu
Xin-min
XM
Qi
Yong-fen
YF
Zhang
Jing
J
Tang
Chao-shu
CS
D000208:Acute Disease; D053607:Adrenomedullin / Q000097:blood / Q000235:genetics* / Q000378:metabolism; D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D058286:Calcitonin Receptor-Like Protein; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics* / Q000378:metabolism; D008168:Lung / Q000378:metabolism / Q000473:pathology; D008171:Lung Diseases / Q000139:chemically induced / Q000235:genetics* / Q000378:metabolism; D008297:Male; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D009479:Neuropeptides / Q000097:blood / Q000235:genetics* / Q000378:metabolism; D019301:Oleic Acid; D010100:Oxygen / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D058262:Receptor Activity-Modifying Protein 1; D058263:Receptor Activity-Modifying Protein 2; D058261:Receptor Activity-Modifying Proteins; D018003:Receptors, Calcitonin / Q000235:genetics* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction
C499411:Adm2 protein, rat; D058286:Calcitonin Receptor-Like Protein; C545580:Calcrl protein, rat; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D009479:Neuropeptides; D012333:RNA, Messenger; C545508:Ramp1 protein, rat; C545509:Ramp2 protein, rat; D058262:Receptor Activity-Modifying Protein 1; D058263:Receptor Activity-Modifying Protein 2; D058261:Receptor Activity-Modifying Proteins; D018003:Receptors, Calcitonin; D053607:Adrenomedullin; D019301:Oleic Acid; D010100:Oxygen