Altersveränderung der Hydroxyprolin-Abgabe bei der thermischen Kontraktion von Kollagenfasern

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Abstract
The hydroxy-proline ("Hypro") content of collagen threads from the rat tail tendon is 11.6% of dry or 4.8% of wet weight (medial values). The water content in 2-month-old animals is 59.8%, in 38-month-old 53.2%. Between these ages the values showed an irregular tendency to decrease. A part of the collagen threads hydroxyproline is already split off in 1% acetic acid and can be determined directly according to Neumann-Logan and with paper chromatography. We call this the easily split Hypro. Its quantity is about 0.2 mg % wet weight or 0.5 mg % dry weight. On heating to 65[degree]C a thermic contraction of the collagen threads occurs. Besides other substances Hypro is liberated which can then be demonstrated in the external fluid. The quantity and the time relations of the release show characteristic differences in animals of differences in animals of different age. The older the animals, the flatter is the curve of release. Hypro is mainly released in complex form. In young animals 2 mg per 100 mg wet weight, that is, about 40% of total Hypro, are released. Only about 0.15 mg % wet weight of directly determinable Hypro are released, but the time curve of release goes parallel to that of the complex Hypro. The easily split Hypro quantity in the elastoid (i.e., the elastoid thread which remains after the thermic contraction) is reduced by the amount released. Their sum gives the quantity in the collagen thread with fairly good accuracy. If one inhibits the thermic contraction by a weight, no Hypro is released at 65[degree]C. This however appears immediately, if, after release of the weight, the contraction occurs. The role of Hypro in the stability of the collagen thread at different ages is discussed and it is mentioned that other substances (mucopolysaccharides and other amino acids) are also released, which will be studied later.