Histochemical analysis of mucosubstances and cytochemical studies of the Golgi region and the secretory granules of the normal gerbil gallbladder principal cells.

The mucosubstances of the gallbladder epithelium of the Mongolian gerbil have been analyzed histochemically. The results indicated that they are composed of carboxylated and sulfated glycoproteins. A closer study of the principal cell structure with ultrastructural and cytochemical technique localized the glycoproteins to the glycocalyx, lysosomes, Golgi complexes, immature and mature secretory granules and basement membrane. Acid phosphatase activity was found in the lysosomes, immature granules and the irregular cisternae of the internal region of the Golgi apparatus. It is suggested that the acid-phosphatase-containing internal Golgi membranes may correspond to the GERL (Golgi-endoplasmic reticulumlysosomes).