title: Guanine nucleotide-binding proteins in aortic smooth muscle from hypertensive rats.
abstract: To explore the hypothesis that altered vascular muscle signal transduction may underlie some of the vascular changes observed in hypertensive models, we measured expression of GTP-binding protein (G protein) alpha-subunits, Gs, G(i), and Gq, in aortic muscle of reduced renal mass and sham-operated rats and proximal and distal aortic segments from rats with interrenal aortic coarctation (IR-AC). G protein expression was measured by immunoblot analysis. When we probed aortic muscle membrane with G(i) and Gq alpha-subunit antibodies, we identified 41- and 42-kD immunoreactive proteins, respectively. Three immunoreactive bands specific to Gs alpha-subunit antibody were resolved. Immunoreactive blot densities were compared. In aortic muscle membrane of reduced renal mass rats (blood pressure, 148 +/- 7 mm Hg), we found significantly reduced Gs and G(i) blot densities compared with sham-operated controls (blood pressure, 99 +/- 12 mm Hg). There were no differences in Gq blot densities between reduced renal mass and control rats. Gs and G(i) blot densities were significantly lower in IR-AC proximal aortic segments (carotid pressure, 165 +/- 5 mm Hg) and distal aortic segments (femoral pressure, 121 +/- 4 mm Hg) than in aortas of sham-operated controls. In contrast, Gq expression was significantly increased in the high-pressure proximal aortic segments compared with low-pressure distal aortic segments from IR-AC rats. Thus, altered G protein expression occurs in aortic muscle from nongenetic rat models of hypertension.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Physiology, Medical College of Wisconsin, Milwaukee 53226.
authors.forename: P
authors.initials: P
authors.lastname: Li
authors.forename: A P
authors.initials: AP
authors.lastname: Zou
authors.forename: N J
authors.initials: NJ
authors.lastname: al-Kayed
authors.forename: N J
authors.initials: NJ
authors.lastname: Rusch
authors.forename: D R
authors.initials: DR
authors.lastname: Harder
mesh_terms: D000818:Animals; D001011:Aorta / Q000378:metabolism*; D001017:Aortic Coarctation / Q000378:metabolism; D019204:GTP-Binding Proteins / Q000378:metabolism*; D006973:Hypertension / Q000378:metabolism*; D015151:Immunoblotting; D008297:Male; D008566:Membranes / Q000378:metabolism; D009131:Muscle, Smooth, Vascular / Q000378:metabolism*; D009392:Nephrectomy; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D019204:GTP-Binding Proteins