Morphologic evidence for collagen changes in chick embryos treated with beta-aminopropionitrile.

Electron microscope analysis of thin sections of intact skin from 17 day chick embryos injected with beta-aminopropionitrile 3 days earlier, revealed markedly increased dispersion in fibril diameter both above and below the narrow distribution of normal fibril size. Extraction with cold 1 M neutral saline caused a dissolution of the fibrils to fine filaments of varying diameters. Histologic examination of the connective tissue of lathyritic skin prior to extraction revealed little difference from the normal. After extraction the collagen either disappeared almost entirely or was observed as a homogeneous smear. These results of morphologic analysis are consistent with previous chemical studies, supporting the thesis that lathyrogenic agents induce disruption of intermolecular cross-linking within normally insoluble collagen fibrils, allowing them to dissolve in cold neutral salt solutions.