Comparison of the Effects of Mechanical Stimulation on Venous and Arterial Smooth Muscle Cells in vitro

Abstract

The proliferation of intimal smooth muscle cells (SMCs) in large muscular arteries and veins often occurs after surgical interventions such as angioplasty and bypass grafting, and may lead to restenosis and graft failure. Clinical observations suggest that increased pulsatile deformation of veins grafted into an arterial position may play a role in intimal hyperplasia. Since intimal hyperplasia occurs at the vein/arterial interface of the graft, SMC hyperplasia could be due to the proliferation of either aortic or venous SMCs. Therefore, we compared the effects of in vitro mechanical deformation on the proliferation of aortic SMCs with venous SMCs. Using the Flexercell^R apparatus (Flex-cell Corp., McKeesport, Pa., USA), aortic SMCs, stretched at 3 and 60 cpm did not lead to a significant increase in growth as compared to the non-stretched controls. In contrast, stretch of venous SMCs at 3 and 60 cpm led to a significant increase in growth as compared to the nonstretched controls. These results suggest that the SMC proliferation, as occurs in vein interposition grafts in vivo, may be partially due to a stimulatory response by venous SMCs to increased mechanical stimulation.

Pressure-Induced Upregulation of Preproendothelin-1 and Endothelin B Receptor Expression in Rabbit Jugular Vein In Situ

“…5 Moreover, venous but not arterial SMCs in culture have been reported to proliferate in response to cyclic strain. 27,28 This effect could also be triggered by ET-1 via the ET B -R 29 and thus contribute to the intimal hyperplasia of venous bypass grafts, which in up to 35% of patients with coronary heart disease causes their failure 1 year after the surgical intervention.…”

The effect of glucocorticoids on proliferation of human cultured airway smooth muscle

“…Amongst the potential mechanisms of action of the glucocorticoids in inhibiting cell proliferation is an action on the eicosanoid pathway, since recent studies indicate that a number of eicosanoids including thromboxane A2 Tomlinson et al, 1994) and cysteinyl leukotrienes (Dethlefsen et al, 1994). Alternative anti-mitogenic actions of dexamethasone include inhibition of the expression of immediate early genes such as c-fos, c-myc, and c-jun (Zhang et al, 1991;Landers & Spelsburg, 1992).…”

Biomechanical regulation of vascular smooth muscle cell functions: from in vitro to in vivo understanding

“…Aortic VSMCs do not show a significant increase in growth when compared with unstretched controls after stretching at 0.05 and 1 Hz. By contrast, stretchings of venous VSMCs both at 0.05 and 1 Hz result in a significant increase in growth when compared with static controls [90,91]. Mechanical stretch increases the synthetic-phenotype behaviour of injured VSMCs in the arterial intima in response to in vitro balloon angioplasty injury [16,81].…”