STAINING OF THE ADENOHYPOPHYSIS WITH ACID AND BASIC DYES1

Abstract

The method of controlled pH staining with acid and basic dyes was applied to the adenohypophyes of male mice, rats, guinea pigs, rabbits and cats. It was found that the 3 classical cell types, acidophiles, basophiles and chromophobes have distinctly different affinities for acid and basic dyes. Acidophiles are stained intensely by acid dye at low pH, and only moderately stained by basic dye at high pH. Basophiles are stained intensely by basic dye at high pH and moderately stained by acid dye at low pH. Thus it is possible on the basis of pH staining to distinguish between acidophiles and basophiles even though both types of cell granules are amphoteric staining with either acid or basic dye. The agranular chromophobes are stained very feebly by either acid or basic dye only at extremes of pH. Ribo-nuclease digestion in conjunction with pH staining shows that the basophilia of the basophiles is distinct from that of the ergasto-plasm. The ergastoplasm is stained by the basic dye to a much lower pH than the basophile granules. The ergastoplasm is present in all cell types and its basophilia is eliminated by ribo-nuclease digestion, whereas the basophilia is only in certain cells and their basophilia is unaffected by the digestion. It follows that the cell granules do not contain appreciable amounts of ribonucleic acid. The species comparison shows that the staining characteristics of the acidophiles and chromophobes are remarkably constant. Species differences in the staining characteristics of the basophiles are noted. Only in the guinea pig, rabbit and cat are these cells selectively, though weakly stained by acid dye at high pH.