Re: Daily Digest

Dear Histonetters,

I am a medical student working in a rat model for selective intra-arterial
drug delivery. The model entails advancing a small (O.9 Fr.) catheter into
the anterior cerebral artery (ACA). Immediately before killing the animal,
I would like to inject some sort of dye that will stain brain parenchyma
within the ACA distribution. I injected methylene blue, after which I did
not perfuse with paraformaldehyde, removed the brain, post-fixed in
formalin, and generated frozen sections. I got a very nice blue stain of
the vessel wall itself, but no parenchymal stain, presumably because brain
microvascular tight junctions prevented efflux of the dye. Next, I tried
raising the infusion pressure and duration in an effort to rupture
capillaries and get a parenchymal staining, but instead all I got was
reflux into the entire circle of willis and still no parenchymal staining.
So it is clear to me I must try some dye other than methylene blue.

My questions for the group are:
1. Does anyone have a suggestion about what dye I can use to get a
parenchymal stain in rat brain when perfusing via intra-arterial catheter
immediately (minutes) before death?
2. If so, will such a stain remain in tact if I follow the selective
(ACA)intra-arterial staining with intra-cardiac perfusion with 4%
3. If anybody has any other idea(s), please offer them... I can use all the
input I can get!

Thanks for allowing me to be a part of the histonet group.

Walt Zink
University of Nebraska

<< Previous Message | Next Message >>