Courtland, H.W-.*; Wright, G. M.; DeMont, M. E.: Physical Properties of Noncollagenous Lamprey Cartilages

Morphological and biochemical studies have demonstrated that lamprey cartilages are different from other vertebrate cartilages in that their major structural components lack collagen and elastin. Notable biochemical and morphological variations even suggest that a family of noncollagenous matrix proteins comprises the lamprey’s cartilaginous skeleton. Yet, in spite of this knowledge, the mechanical properties of these cartilages remain a mystery. In order to further our understanding of cartilage structure-function relations, we conducted a series of stress-relaxation experiments on lamprey annular and pericardial cartilages. Strains of up to 15% were applied in compression (annular) and tension (pericardial). The applied strains and measured equilibrium stresses were used to determine the modulus of elasticity for these cartilages. Our results demonstrate significant differences between the stiffness of lamprey cartilages and other vertebrate cartilages (i.e., hyaline articular cartilage). In addition, there are noticeable differences in stiffness between the two lamprey cartilages.