Summary
The autofluorescence of tendon, epimysium and endomysium at the myotendon junction of the deep digital flexor in the bovine forelimb was measured with a fluorescence microscope and with a bifurcated light guide composed of quartz optical fibres. Data were adjusted for spectral variation in the radiance of the halogen illuminator used to standardize the photometer. Samples of myotendon junction were examined intact, in slices several millimetres thick and after being frozen in liquid nitrogen and sectioned at 20 µm. Sections were examined with and without a mounting medium and with and without immersion oil objectives. Type I collagen fibres were identified by their scarcity of branching, relatively large size and yellow staining with silver. Type III collagen fibres were identified by their extensive branching, small size and black staining with silver. Purified Types I and III collagen were also examined. Type I collagen fibres had a strong fluorescence emission peak between 410 and 450 nm and a shoulder at 510 nm. For the strong peak, results obtained by fibre-optics were positively biased relative to those obtained by microscopy. Type III collagen reticular fibres lacked a strong emission peak at 410 to 450 nm. Although their overall fluorescence was weaker than that of Type I collagen fibres, Type III collagen fibres had similar or slightly stronger emissions around 510 nm. The Type I emission spectrum of collagen fibres was converted to a spectrum similar to the Type III spectrum by conditions that caused the fading of fluorescence (storage as dry or mounted sections and exposure of sections to UV light). It is suggested that, with fibre-optic fluorimetry of intact tissues, Type I collagen fibres may emit a pre-fading spectrum while Type III collagen fibres may emit a post-fading spectrum, and that the preservation of Type I and the fading of Type III collagen is a consequence of the surface to volume ratio of their fibres.
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References
MARTIN, G. R., TIMPL, R., MULLER, P. K. & KUHN, K. (1985) The genetically distinct collagens.Trends Biochem. Sci. 10, 285–7.
PEARSE, A. G. E. (1968)Histochemistry: Theoretical and Applied. Vol. 2, pp. 1171–206. Edinburgh: Churchill Livingstone.
PETERSON, J. I. & VUREK, G. G. (1984) Fiber-optic sensors for biomedical applications.Science 224, 123–7.
PUCHTLER, H., WALDROP, F. S. & VALENTINE, L. S. (1973) Fluorescence microscopic distinction between elastin and collagen.Histochemie 35, 17–30.
SEITZ, W. R. (1984) Chemical sensors based on fiber optics.Anal. Chem. 56, 17–34A.
SWATLAND, H. J. (1982) Elimination of sarcoplasmic argyrophilia in the delineation of muscle fibre boundaries with silver.Mikroskopie 39, 317–22.
SWATLAND, H. J. (1985) Fibre-optic spectrophotometry of immature bovine skeletal muscles and the cellular distribution of myoglobin and succinate dehydrogenase.Histochem. J. 17, 675–82.
UDENFRIEND, S. (1969)Fluorescence Assay in Biology and Medicine. Vol. II, pp. 539–66. New York, London: Academic Press.
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Swatland, H.J. Fluorimetry of bovine myotendon junction by fibre-optics and microscopy of intact and sectioned tissues. Histochem J 19, 276–280 (1987). https://doi.org/10.1007/BF01675687
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DOI: https://doi.org/10.1007/BF01675687