The -SH and SS positive components in dermal connective tissues: a study by N-(7-dimethylamino-4-methyl-3-coumarinyl) maleimide (DACM) stain

Abstract

Although -SH and SS positive components in dermal connective tissue have been observed by N-(7-dimethylamino-4-methyl-3-coumarinyl) maleimide (DACM) stain, their nature is as yet unknown. In our study, we stained several organs such as human skin, rabbit aorta, auricle, and trachea using DACM stain, and studied the distribution of -SH groups and SS linkages among the elastic fibers in those organs. In the dermis of human skin, a moderately strong fluorescence by both -SH and SS stain was present all over the layer, especially in the lower half among collagen fibers in a fine linear or wavy pattern, and a fluorescence ascending vertically from the lower papillary dermis toward the epidermis was also observed. In rabbit aorta, a strong fluorescence by both -SH and SS stain was observed on well-developed elastic fibers. In the matrix of rabbit elastic cartilage, a strong reticular fluorescence by both -SH and SS stain was present. On the other hand, in rabbit hyaline cartilage, no -SH fluorescence was present on any components of the cartilage. However, though a diffuse moderate fluorescence for SS linkages was observed in the matrix, there was no reticular fluorescence such as that seen in the elastic cartilage. These results suggest that the -SH and SS components observed in the dermis by DACM stain are in fact elastic fibers, more precisely, "elastic tissue microfibrils".

SH Abundant Body in Infantile Digital Fibromatosis

“…For the DACM stain, the divided specimen was immediately frozen and stored at -80°C until use. DACM stain was performed on the frozen sections according to the method of Ogawa et al (9) with slight modifications (10). To stain proteinbound free,-SH groups, 3 J.1.m sections were quickly dried and rinsed in cold 5 mM Tris acetate buffer containing 0.85% NaCI, pH 6.8 (TAS), for 5 min.…”