The development of the tibia in hypophysectomized chick embryos

0003-276X

Life and Medical Sciences ; Cell & Developmental Biology

Wiley InterScience Backfile Collection 1832-2000

Medicine

Chick embryos were hypophysectomized by partial decapitation at 33 hours of incubation and the subsequent morphogenesis and growth of the whole embryo and the growth, histology and histochemistry of the tibia studied.Twenty-five percent of the increase in body weight which normally occurs between 12 and 18 days of incubation and 60% of the normal growth of the tibia over the same period failed to occur in the hypophysectomized embryos. Histological studies indicated that the diminished skeletal growth resulted from reduced proliferation of chondroblasts within the epiphyseal growth zone and from reduced deposition of acid mucopolysaccharides into the cartilaginous matrix. The differentiation and hypertrophy of the chondrocytes produced in the hypophysectomized embryos was not affected. Therefore, the pituitary gland exerts considerable control over the development of the cartilaginous skeleton in the embryonic chick.Osteogenesis was reduced as a consequence of the reduced chondrogenesis in the long bones from the hypophysectomized embryos.

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Electronic Resource