Studies of the rings of Henle associated with collagenous bundles in human and calf skin.

Abstract

AbstractThe nature of Henle's rings, which are the highly refractile constricting fibers seen around chemically swollen collagen, has long been in dispute. Several theories can be found in the literature to account for this phenomenon. Henle's rings were abundant in oxhide and calfskin, but were rarely seen in human skin. They did not stain with any of the common elastic tissue stains. Reactions of Henle's rings, collagen fibers, and elastic fibers in purified hexosamine‐free collagen of oxhide, fresh calfskin, fresh human abdominal skin, and ligamentum nuchae were compared using microscopic heat reactions both before and after chemical enzymatic treatment. Solutions used were 50% glycerin, glacial formic acid, 1 N NaOH, 0.1 N acetic acid, 3 N acetic acid, elastase, collagenase, pepsin, and hyaluronidase. The conclusions reached were that Henle's rings are not elastin, mucoid, or protoplasmic in nature but closely resemble a nonswelling collagen, probably reticulin. Henle's rings are very rare in human skin, but after digestion with elastase or treatment with NaOH, long, curving, poorly swelling fibers are seen which react like collagen in other respects. Henle's rings in oxhide varied in diameter from 24 μ up to several hundred microns. They seemed to be made up of fine fibrillae as seen with the phase‐contrast microscope. The fluorescent colors of Henle's rings with various filters differed from the fluorescent colors of elastic fibers. Attempts to stain them with silver were not successful.