title: Glucocorticoid hormone adversely affects the growth and differentiation of cartilage cells in neonatal mice.
abstract: Condylar cartilage of neonatal mice served as an experimental model to study the late in vivo effects of a single dose of a fluorinated synthetic analogue of cortisol on cartilage cell growth and development. Forty-eight hours after the administration of triamcinolone hexacetonide, the proliferative rate of chondroprogenitor cells decreased significantly. However, by the 6th day a marked recovery took place when the total number of 3H-thymidine labelled cells increased by 52.9%, and by 13 days hormone-treated condyles revealed an increase of 93.1% in the total number of labelled cells. At the same time, the magnitude of the chondroprogenitor zone increased by 194.4% and it was found to contain a large population of fibroblast-like cells. The latter were found to synthesize type I collagen and fibronectin, lacked any specific organization and occupied larger portions of the condylar head. Twenty days following the administration of the hormone the newly-formed mass of fibroblast-like cells penetrated the underlying cartilage, split it and formed a direct communication with the marrow cavity. Ultrastructural examination further substantiated the fibroblastic nature of the newly-formed cell population. Hence, it seems very possible that if a corticosteroid hormone is administered to newborn animals it possesses the capacity to affect the normal differentiative pathway of pre-chondroblasts and shift their developmental pathway toward the fibroblastic cell line.
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D002356:Cartilage / Q000032:analysis / Q000166:cytology* / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects; D003094:Collagen / Q000032:analysis; D004721:Endoplasmic Reticulum / Q000648:ultrastructure; D005260:Female; D005347:Fibroblasts / Q000166:cytology; D006056:Golgi Apparatus / Q000648:ultrastructure; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D008928:Mitochondria / Q000648:ultrastructure; D014222:Triamcinolone Acetonide / Q000031:analogs & derivatives* / Q000494:pharmacology
chemical_list: D003094:Collagen; D014222:Triamcinolone Acetonide; C005900:triamcinolone hexacetonide