Effect of Mechanical Loading on Vascular α1D- and α1B-Adrenergic Receptor Expression

摘要: Abstract Heterogeneous distribution and function of α1-adrenergic receptor subtypes on arterial venous vessels, together with evidence for altered α-adrenergic expression in hypertension, led us to examine whether mechanical load influences α1B -and α1D-adrenergic receptors rat aortic smooth muscle cells (SMCs). We used RNase protection radioligand binding assays measure mRNA density. In the first model, SMCs were subjected phasic loading using flexible culture plates. As a positive control stimulus, postconfluent, quiescent passage 5 demonstrated expected load-dependent morphological realignment. However, no changes detected either α1D- or α1B-adrenergic mRNAs density after 24 48 hours loading. β-Actin SMC-specific α-actin mRNA, as well cell number per-cell total RNA protein, also unaffected. second intact thoracic aortas, presence absence endothelial cells, cultured under tonic load. Like did not affect SMC mRNAs. suprarenal coarctation effects increased pressure vivo. previous vitro situ models, hypertension (30 days) had effect α1B- aorta compared sham coarctation. To separate per se from humoral influences, we measured subrenal, normotensive aorta. levels decreased 68±14% sham-coarcted controls subrenal exposed normal blood but systemic induced by effect, loaded organ hypertensive vivo, whereas β-actin was These results culture, vivo models suggest that (load) alone has expression. protected showed decline may be due factor factors.