Acid mucosubstance and basic protein in mouse Paneth cells.

Abstract

The histochemistry of mouse Paneth cell granules was investigated with alcian blue (AB, pH 1.0 or 2.5), periodic acid-Schiff reagent (PAS), high iron diamine (HID) and Biebrich scarlet (pH 9.5). After formalin fixation, an AB pH 2.5-PAS sequence demonstrates alcianophilic rims surrounding weakly PAS-reactive granule cores; the HID-AB and AB pH 1.0-PAS sequences show peripheral staining indicative of a sulfomucin in most granules and a carboxymucin in some granules, the latter predominantly in the distal small intestine. When stained with PAS alone, rims of Paneth granules stain intensely and cores weakly. After HgC12 fixation, HID staining indicative of sulfomucin occurs in the cores of most granules and in the rims of many granules. An AB-Biebrich scarlet sequence shows acid mucosubstance in the rims and strongly basic protein (presumably arginine rich) in the cores of the granules. The basic protein-rich cores are larger toward the bottom of the crypts and toward the distal small intestine. The acid mucosaccharide-rich rims appear thinner surrounding the larger granules at the bottom of the crypts. Fine structural studies have demonstrated dialyzed iron staining indicative of acid mucosubstance in the rims of mouse Paneth cell granules and in small profiles and some lamellae of the Golgi zone.