Invited Symposium: Hypertension III: Flow-Induced Vascular Remodeling
Unthank, JL (Department of Surgery, Indiana University Medical Center, USA)
Prewitt, RL (Department of Physiology, Eastern Virginia Medical School, USA)
This study was designed to characterize structural remodeling of male Wistar rat mesenteric arteries exposed to elevated blood flow in vivo for 1, 3, or 7 days. A series of arterial ligations induced blood flow elevations in ileal and second-order branch arteries compared to same animal control vessels while maintaining normal mean arterial pressures. The primary flow-mediated force in both vessels was shear stress with possible involvement of acute stretch-induced wall stress in the ileal artery. Significant lumen expansion and medial wall hypertrophy concomitant with increases in extracellular connective tissue occurred in the high flow arteries in a time-dependent fashion. Wall thickness:lumen diameter ratios did not change in any vessel at any time, suggesting normalization of flow-induced wall stress occurs through vascular remodeling. Immunostaining for proliferating cell nuclear antigen and nuclear profile analyses indicate medial SMC and intimal EC hyperplasia contributed to flow-induced remodeling of the vessel wall. Endothelial NOS immunoreactivity was detected in the high flow vessels at all time points. Results from in situ hybridization revealed significantly elevated PDGF-A mRNA expression in the media after 24 hours and in the endothelium after 3 and 7 days in the high flow vessels. The findings from this study suggest flow-stimulated arterial remodeling in vivo involves SMC and EC hyperplasia and increases in extracellular connective tissue. This vessel wall restructuring may involve the actions of NO and PDGF-A as regulators of flow-stimulated growth.
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|Tulis, DA; Unthank, JL; Prewitt, RL; (1998). Nitric Oxide Synthase and Growth Factor Expression in Flow-Induced Arterial Remodeling in Rat Mesenteric Vasculature. Presented at INABIS '98 - 5th Internet World Congress on Biomedical Sciences at McMaster University, Canada, Dec 7-16th. Invited Symposium. Available at URL http://www.mcmaster.ca/inabis98/prewitt/tulis0444/index.html|
|© 1998 Author(s) Hold Copyright|