Developmental differences in tracheal cartilage mechanics

Length-tension characteristics were examined in tracheal rings excised from preterm lambs (n = 8) and adult sheep (n = 7) to determine developmental differences in the mechanical properties of tracheal cartilage. Tension was measured in both the complex (comprised of the pars membranacea and its cartilagenous insertion) and the cartilage alone (by severing the pars membranacea) as the ring was lengthened so as to increase the distance between the points of insertion. Analysis of regression lines show significantly greater slopes for both the complex and the cartilage in the adult group compared to the preterm group. These data reveal that age-related differences in tracheal cartilage mechanics parallel and may contribute to age-related differences previously determined in tracheal compliance.