The Structure of Human Skin Collagen as Studied With the Electron Microscope

Abstract

1. The structure of the collagen fibrils of normal human skin corium has been investigated with the electron microscope. 2. Under the conditions of observation the fibrils ranged in width from about 700 to 1,400 A with 1,000 A as the value occurring most frequently. They showed little tendency to fray longitudinally as is characteristic of tendon fibrils; when fracture of fibrils occurred it was usually in planes transverse to the axis. 3. The axial repeating periods observed in fibrils stained with phosphotungstic acid or shadowed with chromium or platinum range from about 500 to 800 A, the maximum occurring between 620 and 660 A. The average period in fibrils from infant skin does not differ significantly from that of adult and aged skin. 4. Depending on conditions of preparation, intraperiod fine structure, in the form of cross-bands, was observed in varying detail. The most detailed pattern commonly observed contains six bands of characteristic density and position. 5. Shadowed plastic replicas of dried collagen fibrils reproduce much of the structure commonly seen in shadowed fibrils. Replicas of moist fibrils show considerably less surface contouring than do dried fibrils. Replicas from smears of connective tissue fragments on glass show detailed structure, indicating the feasibility of applying this technique to biopsy material. 6. Infant skin differs from adult skin in having considerably greater amounts of amorphous material, little of which is strongly adherent to the collagen fibrils.

Ultrastructural and Biochemical Studies on a Case of Elastosis perforans serpiginosa

“…Collagen fibers with a mean diameter around 1,000 A, typical of normal adult human dermis, were absent. The majority of the collagen fibers had a diameter around 480-500 A similar to those observed in embryonic skin [21,22], In some areas the collagen fibers exhibited a diameter of less than 300 A. In this latter case the collagen bundles appeared very often to dissolve into a net work of microfilaments.…”

“…At the ultrastructural level, both collagen and elastin fibers appeared to differ from those of normal adult dermis and to show similarities with immature fibers [21,22]. In many areas the elastic substance was organized as narrow strands mixed with microfilaments and tubular microfibrils, similar to those described for newly forming elastic fibers [21].…”

The silk road of Tetranychus urticae: is it a single or a double lane?

“…c The two pedipalps of a female. Silken threads are spun through two eupathids (micrograph of LR Tiedt, NWU, RSA) threads of collagen (2-20 lm) (Gross and Schmitt 1948) and elastin (4.5-6.0 lm) (Gotte et al 1972). Compared to other spinning arthropods, the tiny silken threads found in T. urticae may have different physical and mechanical properties (e.g., strength or elasticity).…”

The distribution of the growth of collagen in the uterus of the pregnant rat

“…It seems not unreasonable to suppose such a mechanism might exist in view of the fact that the smaller fibrils of collagen seen with the electron microscope do seem to be generally rather constant in diameter (e.g. Hall, Jakus & Schmitt, 1942;Gross & Schmitt, 1948), though this is not an absolutely universal rule and there is variation of the diameter with age (e.g. Gross, 1950;Banfield, 1955).…”