Uranyl acetate

Tissues of all groups were fi xed in phosphate buffer containing 2.5 % glutaraldehyde (Sigma-Aldrich Co.) for 2-3 h, post-fi xed in 1 % osmium tetra oxide (Sigma-Aldrich Co.) and dehydrated in a series of graded alcohols (50, 60, 70, 80, 90, 96 and 100 % ethanol). After passing through propylene oxide (Sigma-Aldrich Co.), the specimens were embedded in Araldite CY 212 (Ciba-Geigy), (2-dodecen-1-yl) succinic anhydride (Sigma-Aldrich Co.), benzyldimethyl amine (Poly Sciences Inc.) and dibutylphtalate (Sigma-Aldrich Co.). The semi-thin sections were stained with toluidine blue (Sigma-Aldrich Co.), and examined with a photomicroscope (Leica DM4000, Germany). After the selection of appropriate specimens, thin sections were cut and stained with uranyl acetate (Pro Sci Tech) and lead citrate (Sigma-Aldrich Co.). They were examined by means of an electron microscope (Carl Zeiss EM 900, Germany) (17) .

Tissues from all the groups were fixed in phosphate buffered solution (Ph= 7.3) containing 2.5% glutaraldehyde (Sigma-Aldrich Co.) for 2 h at room temperature, post-fixed in 1% osmium tetraoxide (Sigma-Aldrich Co.) and dehydrated in a series of graded alcohols (50, 60, 70, 80, 90 and 100% ethanol). After passing through propylene oxide (Sigma-Aldrich Co.), the specimens were embedded in Araldite CY 212 (Ciba-Geigy), (2-dodecen-1-yl) succinic anhydride (Sigma-Aldrich Co.), benzyldimethylamine (Poly Sciences Inc.) and dibutylphtalate (Sigma-Aldrich Co.). The semi-thin sections were stained with toluidine blue (Sigma-Aldrich Co.) and examined with a photomicroscope (DM 500 Leica, Germany). After the selection of appropriate specimens, thin sections were cut, stained with uranyl acetate (ProSciTech) and lead citrate (Sigma-Aldrich Co.), and examined via an electron microscope by two blinded histologists (Leo 906 e Carl Zeiss, Germany).