Growth and development of the human cricoid cartilage: an immunohistochemical analysis of the maturation sequence of the chondrocytes and surrounding cartilage matrix.

Abstract

The goal was to determine maturational changes in the human cricoid cartilage. The study involved immunohistochemical staining of collagen II (a marker of proliferating chondrocytes), matrilin-1 (a marker of post-proliferative chondrocytes), and collagen X (a marker of hypertrophic chondrocytes). Specimens included uninjured human cricoid cartilages at 18 and 41 weeks' gestation and 1, 4, and 13 years postpartum. This study demonstrated that type II collagen peaks in concentration at approximately 41 weeks' gestation. Matrilin-1 is present in progressively lower concentration in the central core of the cricoid ring, but the peripheries of the ring contain the protein in relatively high concentration. Type X collagen is not expressed in the age groups tested. These biochemical markers lend further support to a chondrocyte proliferative phase that slows between 1 and 4 years of age. Chondrocytes then enter a phase histologically similar to the hypertrophic phase but are biochemically different than hypertrophic chondrocytes destined for endochondral ossification.