This Is MS Multiple Sclerosis Community: Knowledge & Support

I wonder if low blood pressure has something to do with why some people have stenosis that comes and goes. On page 19 of Dr. Simka’s presentation at the CCSVI workshop held in Toronto back On Feb 7/10, he wrote under interesting finds: It is difficult to explain these findings in terms of improved nerve function; rather – it is more likely that a blood-release neurotransmitter may play a role (angiotensin??).

http://www.ms-mri.com/docs/Simka-hamilton%20-ccsvi-1.pdf

I decided to read up more on the word angiotensin and come across the renin-angiotensin system. Some people with MS complain of low blood pressure.

The renin-angiotensin system (RAS) or the renin-angiotensin-aldosterone system (RAAS) is a hormone system that regulates blood pressure and water (fluid) balance.
When blood volume is low, the kidneys secrete renin. Renin stimulates the production of angiotensin. Angiotensin causes blood vessels to constrict, resulting in increased blood pressure. Angiotensin also stimulates the secretion of the hormone aldosterone from the adrenal cortex. Aldosterone causes the tubules of the kidneys to increase the reabsorption of sodium and water into the blood. This increases the volume of fluid in the body, which also increases blood pressure.
If the renin-angiotensin-aldosterone system is too active, blood pressure will be too high. There are many drugs that interrupt different steps in this system to lower blood pressure. These drugs are one of the main ways to control high blood pressure (hypertension), heart failure, kidney failure, and harmful effects of diabetes.[2][3]

http://en.wikipedia.org/wiki/Renin-angiotensin-aldosterone_system

Could low blood pressure cause a temporary stenosis for some people? Especially if the connective tissue in MS switches from collagen I to collagen III. Maybe the viens are less flexible and slower to open back up.