Macromolecular orientation (evaluated from linear dichroism findings) and isoelectrical point were investigated on periodontal fibers of adult rats and compared with data on tendon and cementum collagen bundles. Linear dichroism data pointed out similarities on protein orientation, but some differences concerned with patterns of acid mucopolysaccharides orientation could be shown, as for instance, the absorption maxima on periodontal fibers oriented parallel and perpendicular to the plane of polarized light are both placed at the same wavelength, what is in accordance with findings on the rat cementum, but differs from patterns for adult tendon collagen fibers under same experimental conditions. On the other hand, they are quite similar to those found in the early stages of experimental regenerations of the tendon collagen. Also differences concerned with the wavelength of the absorption peak in the parallel direction were shown in sections impregnated with silver and gold. These modifications of dichroism patterns which are indicative of differences in molecular orientation are assumed as being related to a less evolved degree of maturity of the collagen fibers in the rat periodontium, which is supported by morphology and birefringenee observations. Less orientation of the maeromolecules is shown in the plexus region of the periodontium as compared with the j uxtacementar zone. The apparent isoelectrical point was found as being placed within the range which is usually reported for collagen bundles. Ver menos

Macromolecular orientation (evaluated from linear dichroism findings) and isoelectrical point were investigated on periodontal fibers of adult rats and compared with data on tendon and cementum collagen bundles. Linear dichroism data pointed out similarities on protein orientation, but some differences concerned with patterns of acid mucopolysaccharides orientation could be shown, as for instance, the absorption maxima on periodontal fibers oriented parallel and perpendicular to the plane of polarized light are both placed at the same wavelength, what is in accordance with findings on the rat cementum, but differs from patterns for adult tendon collagen fibers under same experimental conditions. On the other hand, they are quite similar to those found in the early stages of experimental regenerations of the tendon collagen. Also differences concerned with the wavelength of the absorption peak in the parallel direction were shown in sections impregnated with silver and gold. These modifications of dichroism patterns which are indicative of differences in molecular orientation are assumed as being related to a less evolved degree of maturity of the collagen fibers in the rat periodontium, which is supported by morphology and birefringenee observations. Less orientation of the maeromolecules is shown in the plexus region of the periodontium as compared with the j uxtacementar zone. The apparent isoelectrical point was found as being placed within the range which is usually reported for collagen bundles. Ver menos