title: Alterations of angiotensin II receptor contents in hypertrophied hearts.
abstract: Tsukuba hypertensive mice, which carry the human genes for renin and angiotensinogen, show cardiac hypertrophy as well as hypertension due to activation of the renin-angiotensin system (RAS). Here, we compared the cardiac angiotensin II (Ang II) receptor contents in these and normotensive control mice by means of ligand binding studies and competitive reverse transcription-polymerase chain reaction analyses. The content of the Ang II receptor type 1 (AT1) was significantly higher at both the protein (2.5-fold; p < 0.01) and mRNA (1.4-fold; p < 0.05) levels in the hypertensive mice than that in control mice. Almost identical levels of the Ang II receptor type 2 (AT2) expression were identified at the mRNA levels in the two types of mice, although the levels were less than 20% of those of AT1 mRNA in control mice. These results suggest that AT1 in the heart is upregulated in response to Ang II-induced hypertrophic change and that, in particular, the upregulation of AT1 in particular contributes to the development and/or maintenance of cardiac hypertrophy in conjunction with the increase in Ang II production, because AT1 is responsible for cardiac hypertrophy related to the RAS.
authors.affiliation: Institute of Applied Biochemistry, Gene Experiment Center, University of Tsukuba, Ibaraki, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Fujii
authors.forename: M
authors.initials: M
authors.lastname: Tanaka
authors.forename: J
authors.initials: J
authors.lastname: Ohnishi
authors.forename: K
authors.initials: K
authors.lastname: Yukawa
authors.forename: E
authors.initials: E
authors.lastname: Takimoto
authors.forename: S
authors.initials: S
authors.lastname: Shimada
authors.forename: M
authors.initials: M
authors.lastname: Naruse
authors.forename: F
authors.initials: F
authors.lastname: Sugiyama
authors.forename: K
authors.initials: K
authors.lastname: Yagami
authors.forename: K
authors.initials: K
authors.lastname: Murakami
mesh_terms: D000818:Animals; D001483:Base Sequence; D006332:Cardiomegaly / Q000378:metabolism*; D006973:Hypertension / Q000378:metabolism*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D009206:Myocardium / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000378:metabolism; D012194:RNA-Directed DNA Polymerase / Q000378:metabolism; D011945:Receptors, Angiotensin / Q000235:genetics / Q000378:metabolism*
chemical_list: D012333:RNA, Messenger; D011945:Receptors, Angiotensin; D012194:RNA-Directed DNA Polymerase