1: Am J Physiol Heart Circ Physiol. 2000 Mar;278(3):H748-54. 

Physiological cyclic stretch causes cell cycle arrest in cultured vascular
smooth muscle cells.

Chapman GB, Durante W, Hellums JD, Schafer AI.

Department of Bioengineering, Rice University, Houston, TX 77005, USA.

Smooth muscle cells (SMC) are the major cellular component of the blood vessel
wall and are continuously exposed to cyclic stretch due to pulsatile blood flow.
This study examined the effects of a physiologically relevant level of cyclic
stretch on rat aortic vascular SMC proliferation. Treatment of static SMC with
serum, platelet-derived growth factor, or thrombin stimulated SMC proliferation,
whereas exposure of SMC to cyclic stretch blocked the proliferative effect of
these growth factors. The stretch-mediated inhibition in SMC growth was not due
to cell detachment or increased cell death. Flow cytometry analysis revealed
that cyclic stretch increased the fraction of SMC in the G(0)/G(1) phase of the
cell cycle. Stretch-inhibited G(1)/S phase transition was associated with a
decrease in retinoblastoma protein phosphorylation and with a selective increase
in the cyclin-dependent kinase inhibitor p21, but not p27. These results
demonstrate that cyclic stretch inhibits SMC growth by blocking cell cycle
progression and suggest that physiological levels of cyclic stretch contribute
to vascular homeostasis by inhibiting the proliferative pathway of SMC.

PMID: 10710342 [PubMed - indexed for MEDLINE]