title: Expressions of adrenomedullin mRNA and protein in rats with hypobaric hypoxia-induced pulmonary hypertension.
abstract: Experimental pulmonary hypertension induced in a hypobaric hypoxic environment (HHE) is characterized by structural remodeling of the heart and pulmonary arteries. Adrenomedullin (AM) has diuretic, natriuretic, and hypotensive effects. To study the possible effects of HHE on the AM synthesis system, 150 male Wistar rats were housed in a chamber at the equivalent of a 5,500-m altitude level for 21 days. After 14 days of exposure to HHE, pulmonary arterial pressure (PAP) was significantly increased (compared with control rats). The plasma AM protein level was significantly increased on day 21 of exposure to HHE. In the right ventricle (RV), right atrium, and left atrium of the heart, the expressions of AM mRNA and protein were increased in the middle to late phase (5-21 days) of HHE, whereas in the brain and lung they were increased much earlier (0.5-5 days). In situ hybridization and immunohistochemistry showed AM mRNA and protein staining to be more intense in the RV in animals in the middle to late phase of HHE exposure than in the controls. During HHE, these changes in AM synthesis, which occurred strongly in the RV, occurred alongside the increase in PAP. Conceivably, AM may play a role in modulating pulmonary hypertension in HHE.
authors.affiliation: Department of Pathology, National Defense Medical College, Tokorozawa 359-8513, Japan. nknsknak@res.ndmc.ac.jp
authors.forename: Kuniaki
authors.initials: K
authors.lastname: Nakanishi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Osada
authors.forename: Maki
authors.initials: M
authors.lastname: Uenoyama
authors.forename: Fumiko
authors.initials: F
authors.lastname: Kanazawa
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Ohrui
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Masaki
authors.forename: Takuya
authors.initials: T
authors.lastname: Hayashi
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Kanatani
authors.forename: Tomosumi
authors.initials: T
authors.lastname: Ikeda
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Kawai
mesh_terms: D053607:Adrenomedullin; D000818:Animals; D001273:Atmosphere Exposure Chambers; D001835:Body Weight; D006332:Cardiomegaly / Q000378:metabolism / Q000503:physiopathology; D006400:Hematocrit; D006976:Hypertension, Pulmonary / Q000378:metabolism / Q000503:physiopathology*; D000860:Hypoxia / Q000378:metabolism / Q000503:physiopathology*; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008297:Male; D010455:Peptides / Q000235:genetics* / Q000378:metabolism*; D011669:Pulmonary Wedge Pressure; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D010455:Peptides; D012333:RNA, Messenger; D053607:Adrenomedullin