[Histonet] cresyl violet on mouse placentae

[Jacqui Detmar]

Hi all.  I need some help interpreting my results.  I have tried (twice) posting a picture on the histonet.org site, but I think my emails are going off into cyberspace.  Anyway, I treated female mice with polycyclic aromatic hydrocarbons (PAHs; BaP and DMBA) for 6 weeks, then waited one week and mated the mice.  When I collected the placentae and fetuses at d15.5 (mouse gestation is approx. 19 days), the fetuses were growth-restricted, but the placental weight was the same as controls.  I wanted to see if there were any mast cells in the placenta, so I applied a cresyl violet stain I had downloaded from the internet (0.5% CV in 1% glycerol).  I didn't see any mast cells, but what I *did* see were numerous rust-coloured deposits in the labyrinth (site of fetal-maternal exchange) of the treated placentae.  I showed my pictures to a veterinary pathologist and he thought they might be hemosiderin or an iron-based deposit.  When I did a Perl's Prussian Blue and a Turnbull reaction on the sections, I didn't see increased iron deposits in the tissue.  Could somebody help me out with this?  If you need/want pictures, please let me know.  The .tif file is about 280 kb.

Thanks,

Jacqui Detmar
Samuel Lunenfeld Research Institute,
Mount Sinai Hospital.
Toronto, Ontario, Canada