Some histochemical reactions of mast cells of gerbils,hogs, armadillos and cats

Summary Mast cells of the Mongolian gerbil Meriones unguiculatus, the hog Sus scrofa, the cat Felis catus and the armadillo Pasypus novemcinctus were studied histochemically in relation to various fixation procedures, using azure A at pH 1 and 3, alcian blue at pH 1 and 2.5, diazosafranin at pH 3 and 7.8–8, and the PAS reaction. Fixations were performed in buffered 10% formol and 5% glutaraldehyde, in Kose's fluid, buffered sublimate (B4), lead nitrate and lead acetate formol.With azure A and alcian blue many mast cells were found in the gerbil with the aldehyde fixatives, fewer with the heavy metals. The diazosafranin reaction was present only in the aldehyde material, the PAS reaction was negative.In the hog, mast cells were more numerous after heavy metal fixation, fewer with aldehydes. Azure A stained metachromatically at pH 1 and 3, alcian blue reacted only at pH 1, the PAS reaction was negative, the pH 3 and 8 diazosafranin reactions were positive with all 4 fixations.In the cat, mast cells were moderately numerous with lead acetate formol, rare with formol and absent with glutaraldehyde. They stained with azure A at pH 1 and 3, with alcian blue at pH 1 and 2.5, with diazosafranin at pH 3 and 8 and by the PAS reaction.Armadillo mast cells were more numerous after heavy metal fixations, stained with azure A and alcian blue at pH 1 and 2.5 to 3, and with acid and alkaline diazosafranin.The mast cells of the 4 species vary in their requirements for aldehyde and heavy metal fixation, in their PAS reactivity and in their pH 2.5 alcian blue staining. All are sufficiently sulfated to react to cationic dyes at pH 1, but vary in PAS reactivity, indicating partial or complete sulfation. The presence of 5-hydroxytryptamine is indicated in all four species.Assisted by grant from National Cancer Institute C-04816.