THE PRESENCE OF LYSYLPYRIDINOLINE IN THE HYPERTROPHIC CARTILAGE OF NEWLY-HATCHED CHICKS

The presence of lysylpyridinoline (LP) as a nonreducible cross-link in appreciable quantities has primarily been limited to the mineralized tissues, bone and dentin. However, the results reported here show that LP is not only present in the hypertrophic cartilage of the tibiotars us isolated from newly hatched broiler chicks, but it is approx. 4-fol d as concentrated as hydroxylysylpyridinoline (HP). Bone and articular cartilage surrounding the hypertrophic cartilage do not contain measu rable quantities of LP. Purified LP has a flourescent scan similar to purified HP and literature values, confirming that we indeed were meas uring LP. Also, the cartilage lesion produced by immature chondrocytes from birds with tibial dyschondroplasia had LP but the HP: LP ratio w as > 1. Thus, the low HP:LP ratio could be a marker for hypertrophic c artilage in avians.