Type-VI collagen as a major component in the interstitial matrix of cutaneous mechanoreceptors.

The presence or absence of type-VI collagen in mechanoreceptors in the lips and palate of the mouse and gerbil was assessed histochemically. When fresh palatine mucosae and the lips of mice were incubated in 20 mM ATP solution, numerous fibrous long spacing fibers with a periodicity of 100 nm appeared in the interlamellar spaces of Meissner's corpuscles, simple lamellated corpuscles, and the peripheral connective tissue of Ruffini's nerve endings, irrespective of age. In addition, when the palatine mucosae of mice and gerbils were stained immunohistochemically with anti-type-VI collagen, an intensely positive reaction was constantly observed in Meissner's corpuscles. Furthermore, a less intense immunoreaction to anti-type-VI collagen was recognized in the inner core of simple lamellated corpuscles and Ruffini-like formations in the labial mucosae. From these results, we conclude that type-VI collagen is a major constituent of the interstitial connective tissue of cutaneous mechanoreceptors.