Hypertension III: Flow-Induced Vascular Remodeling

Re: Dr. J. Unthank (0779) Shear-mediated luminal expansion

Joseph L. Unthank

On Thu Dec 10, Robert M.K.W. Lee wrote
>     It is interesting that the increase in endothelial cells occurs first, followed by the increase in the medial smooth muscle cells, and then there is a period of readjustment of the cell number.  I wonder if vascular beds in older animals are capable of these types of changes.

Dear Dr. Lee,

Thank you for your insightful question.  Langille and Masuda were the first to show that endothelial changes in response to altered flow occurred before medial changes.  From the data available in their studies in large arteries and ours in small arteries, I suspect that these changes can occur in older animals but may require either or both longer time periods or greater stimuli.  I would also hypothesize that the suppression that may occur with age is correlated with the development of endothelial dysfunction.  In the data presented by Tuttle, we did see evidence of endothelial proliferation in collaterals of mature animals, even when luminal expansion had not occurred.  We have not yet performed longer term studies to investigate how remodeling proceeds in these older animals.

Thanks for your comments,


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