Safe Stimulation of Stem Cells by GCSF and Vessel Maintenance

I am often asked if the administration of GCSF is safe. Well, lots of stem cell donors undergo peripheral blood stem cell stimulation and harvesting for donation to a loved one and so far, no adverse reactions have been reported or observed (numbers are estimated to be >40,000 worldwide every year).

It was significant that the GCSF heart trial took place in Germany (see previous entry-Stem Cells for Heart Disease) and that other similar trials are also taking place in other institutions (Baxter trial, Schaer trial) and that although the stimulation of stem cells didn't improve their condition, it certainly did not make them any worse off.

Just a thought- It's already known that GCSF levels in the body rise in response to tissue damage and that stem cells probably need to be administered to site of damage- do circulating stem cells help in maintaining the rest of the peripheral blood vessels protecting them as best they can as long as no congestion or sustained disease is impeding its work?

Under normal circumstances of wear and tear (blood does flow at pretty high pressures near the heart, and like piping, needs regular maintenance), circulating stem cells might play a role in the upkeep of these vessels. Like a traveling sentinel that keeps things in check. I wonder if anyone out there might be thinking of how to devise a study on this...