Guanine nucleotide-binding proteins in aortic smooth muscle from hypertensive rats

Pinlan Li, Ai Ping Zou, Nabil J. Aj-Kayed, Nancy J. Rusch, David R. Harder

Research output: Contribution to journalArticlepeer-review

24 Scopus citations


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) o-subunits, G, Gi 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 Gi, and Gq a-subunit antibodies, we identified 41- and 42-kD immunoreactive proteins, respectively. Three immunoreactive bands specific to G, a-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 G, and G, blot densities compared with sham-operated controls (blood pressure, 99±12 mm Hg). There were no differences in Gq blot densities between re- duced renal mass and control rats. G, and G, 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 shamoperated 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. Given the differences between reduced renal mass and IR-AC models, it is clear that pressure is not the only variable regulating G protein expression and that hormonal and/or metabolic influences probably play a larger role.

Original languageEnglish (US)
Pages (from-to)912-918
Number of pages7
Issue number6
StatePublished - Jun 1994
Externally publishedYes


  • G protein
  • Hypertension experimental
  • Muscle smooth vascular
  • Rats

ASJC Scopus subject areas

  • Internal Medicine


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