Histochemical Study of Protein-bound Sulfhydryl and Disulfide Groups in Normal Salivary Glands

¹ Department of Oral Surgery and Histochemical Laboratory, Osaka University Dental School, Osaka, Japan

Protein-bound sulfhydryl and disulfide groups in the three major salivary glands of the rat, mouse, hamster, guinea pig, rabbit, and dog were demonstrated histochemically by the neotetrazolium chloride and DDD methods.

No significant difference in histochemical localization of sulfhydryl groups was observed served in comparing the neotetrazolium and DDD methods; however, the neotetrazolium method gave better localization.

Thioglycolic acid was chosen as the reducing agent for disulfide groups and monoiodide acetic acid as the blocking agent for sulfhydryl groups. In the salivary gland the sulfhydryl groups were more abundant than the disulfide groups, and the localization of the sulfhydryl and disulfide groups was very similar.

A strong reaction of protein-bound sulfhydryl groups was observed in the duct cells in the three major salivary glands. Serous acinar cells of the parotid and submandibular salivary glands reacted moderately and the cytoplasm of mucinous acinar cells of the sublingual gland showed negative results, though slight reactions were observed at the basal portions of acinar cells. In regard to the demonstration of both sulfhydryl and disulfide groups, a faint staining in the nucleoli and nuclear membrane of parotid and submandibular acinar cells was observed.

By visual estimation, no remarkable quantitative difference of sulfhydryl and disulfide groups was observed among the six different species.