Effects of thyroid hormones on cartilage sulphation in sex-linked dwarf chickens

The present investigation was undertaken to see if exogenous thyroid hormome could stimulate cartilage sulphation in vivo and in vitro in sex-linked dwaft chickens B-thyroxine or 1-3,5,5-triiodothyronine injection for 7 consecutive days stimulated in vivo 35SO2-4 incorporation into trachea cartilages of the dwarf chicken. Both thyroid hormones added to the incubation medium with or without 2.5% dwarf chicken serum also stimulated in vitro 35SO2-4 incorporation into pelvic rudiment from 11-day chick embryos. These data demonstrate that thyroid hormones, like insulin-like growth factor 1, might be responsible for the reduced growth rate of dwarf chickens.