title: A major role for AT1b receptor in mouse mesenteric resistance vessels and its distribution in heart and neuroendocrine tissues.
abstract: In mice, angiotensin (Ang) II type-1 (AT(1)) receptors exist as AT1a, and AT(1b) subtypes. In an effort to understand the role of AT(1b) in regulating vascular function, AT(1) subtype mRNA and its functional relevance in the mesenteric resistance vessels were determined using wildtype (WT) and AT(1a) knockout (AT(1a)(-/-) mice) mice. With RT-PCR followed by restriction-enzyme digestion, we found that AT(1b) accounted for almost all (98%) of AT(1) receptors in the mesenteric resistance vessels of WT mice. Also, the Ang II response in the vessels of AT(1a)(-/-) mice was comparable to that of WT mice, suggesting an important role for AT(1b) in regulating vasoreactivity. To further characterize AT(1b) receptor distribution, several other tissues were examined. Among them, AT(1b) is only predominantly expressed in hypothalamus, whereas AT(1a) exists exclusively or as a major subtype in heart, pituitary, adrenal glands and brainstem. These results further underscore a tissue-specific role for AT(1b) receptor in mice.
authors.affiliation: Davis Heart and Lung Research Institute, College of Medicine and Public Health, The Ohio State University, 375 W12th Avenue, Columbus, OH 43210, USA.
authors.forename: Yingbi
authors.initials: Y
authors.lastname: Zhou
authors.forename: Wessel P
authors.initials: WP
authors.lastname: Dirksen
authors.forename: Yanfang
authors.initials: Y
authors.lastname: Chen
authors.forename: Mariana
authors.initials: M
authors.lastname: Morris
authors.forename: Jay L
authors.initials: JL
authors.lastname: Zweier
authors.forename: Muthu
authors.initials: M
authors.lastname: Periasamy
mesh_terms: D000803:Angiotensin I / Q000494:pharmacology; D000818:Animals; D015870:Gene Expression; D008297:Male; D008638:Mesenteric Arteries / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D051379:Mice; D018345:Mice, Knockout; D009206:Myocardium / Q000737:chemistry / Q000378:metabolism*; D009490:Neurosecretory Systems / Q000737:chemistry / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism; D044140:Receptor, Angiotensin, Type 1 / Q000235:genetics / Q000502:physiology*
chemical_list: D012333:RNA, Messenger; D044140:Receptor, Angiotensin, Type 1; D000803:Angiotensin I