The vital staining of normal and malignant cells. III. Vital staining of acinar cells of the pancreas and its bearing on the theories of vital staining with basic dyes

Abstract

In mouse pancreas preparations demonstrating mitochondria there is a canalicular system. Osmic and Ag impregnation meth- ods show this as a black network[long dash]the Golgi apparatus. Secretion granules arise in intimate relationship with this network. Impregnation of it by the osmic technique is not influenced by ether anesthesia extending over 3 hrs. After intra-vital staining with neutral red, dye droplets appear in the cells, which can be retained in permanent preparations, and are localized where, in other preparations, is seen the canalicular system or Golgi apparatus. The changes undergone by the Golgi apparatus during cell autolysis differ from those figured as characteristic of vital staining. Intense intra-vital staining with neutral red leads to the formation within the cell of deposits which can be stained in permanent preparations by the eosin-azur method. Such granules are not formed after intense staining with the diffuse-staining dyestuff rhodamin B. It is therefore concluded: There is no fundamental difference between vital staining with an acid dye, such as trypan blue, and a basic dye, such as neutral red. Both give rise to new formations in the cell, and both under certain conditions can stain preformed structures, such staining being determined by the physico-chemical properties of the bodies stained. Many types of cells which are permeable to basic dyes are, however, impermeable to acid dyes. There is present in the acinar cells of the pancreas a reticulate structure, or canalicular system, distinct from the mitochondria. When such cells are stained intra-vitally with neutral red, dye droplets are formed, either within the strands of the reticulate structure, or else in direct contact with it.