Histological study, including ultrastructural quantification, of the periodontal ligament in the lathyritic rat...

A 0.15 per cent solution of aminoacetonitrile was added to the drinking water of young adult male Wistar rats for 18 days. Their right mandibular incisors were maintained unimpeded by frequent trimming. After 18 days, the periodontal ligaments of the right mandibular incisors and first molars were prepared for light and electron microscopy. For control purposes, similar material was obtained from animals fed on a normal diet ad libitum or pair-fed. With light microscopy, lathyritic incisor periodontal ligaments showed areas of normal connective tissue appearance interspersed with areas of degeneration. In the lathyritic molars, cell-free areas were observed. With electron microscopy, quantification of features in the connective tissue regions of the lathyritic ligament showed little change. In cell-free areas, many collagen fibrils had smaller fibril diameters than normal.