Differential Staining of the Anterior Pituitary Gland of the Cat

Abstract

The terms “acidophile” and “basophile” as applied to the two recognized types of chromophilic cells of the anterior pituitary have been sanctioned by long usage. Nevertheless, these cells do not always give a specific reaction to acid and basic dyes respectively. The difficulty of classification has been further complicated by the demonstration of an additional tinctorial type in the female rabbit and cat which has been provisionally classed as a modified acidophile. This distinction is based on the differential staining reaction obtained with Heidenhain's “azan” technic following sublimate-formalin fixation, the standard acidophile reacting with orange G, the modified type with azocarmine.

Both of these cells are stained with copper hematoxylin, Heidenhain's iron hematoxylin, Mallory's phosphotungstic acid hematoxylin and Kultschitzky's acetic hematoxylin. However, Hansen's chroroalum hematoxylin stains the basophiles intensely and also reacts very slightly with the so-called modified acidophile.

The orange G + phosphomolybdic acid + hematoxylin method of Hall and Hunt stains the basophiles more or less selectively when applied progressively, altho the special cells also react. When regressive staining is employed, the results vary depending on the fluid used. Following successful differentiation with Weigert's borax f erricyanide, the basophiles are decolorized and the modified acidophils are deep blue, while the ordinary acidophiles retain the orange G. These staining reactions are unmodified after Bouin's fixation.

It is concluded that the weight of evidence favors the classification of the special cell as a modified type of acidophile.