Journal ArticleDOI
Rate of normal longitudinal bone growth in the rat.
TLDR
The rate of normal growth in length from the proximal growth plate of the tibia in the Sprague-Dawley rat was measured between 20 and 100 days of age using the tetracycline method and was highest in young animals and decreased considerably with increasing age.Abstract:
The rate of normal growth in length from the proximal growth plate of the tibia in the Sprague-Dawley rat was measured between 20 and 100 days of age using the tetracycline method. The growth rate varied only slightly within different age groups. The rate was highest in young animals and decreased considerably with increasing age. Male rats grew faster than female. This study is intended to provide a base for an evaluation of experimental influence on the growth in length of the rat.read more
Citations
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Skeletal Effects of Estrogen
TL;DR: Estrogen appears to be the most important sex steroid in preventing osteoporosis in women and is the subject of this review.
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Sexual dimorphism in the control of growth hormone secretion.
TL;DR: A feminization of the liver develops after continuous, but not intermittent, administration of GH to hypophysectomized rats, suggesting that high, infrequent GH pulses with low plasma GH levels in between promotes growth more effectively than an intermediate, rather constant level of plasma GH.
Journal ArticleDOI
Growth Hormone Stimulates Longitudinal Bone Growth Directly
TL;DR: This finding suggests that growth hormone directly stimulates the cells in the growth plate, and does not support the theory that the increase in the plasma concentration of somatomedin that follows growth hormone administration is the cause of this stimulation.
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Mode of Action of Pituitary Growth Hormone on Target Cells
TL;DR: It is suggested that, during the process of chondrocyte differentiation in the growth plate, the genes that code for growth factors of the somatomedin class, such as IGF-I, are expressed and, as a consequence, the clonal expansion of the chONDrocytes in the proliferative zone of the growth Plate that occurs in vivo during theprocess of normal growth is the result of this local production of growth factors.
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Mechanism of longitudinal bone growth and its regulation by growth plate chondrocytes.
TL;DR: The contributions made by various activities during the course of the chondrocyte life cycle are delineated and how the relative contributions may be modulated according to the particular needs of an organism at critical phases of growth is illustrated.
References
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Journal ArticleDOI
CELL DIVISION IN ENDOCHONDRAL OSSIFICATION: A Study of Cell Proliferation in Rat Bones by the Method of Tritiated Thymidine Autoradiography
TL;DR: The pattern of tritiated thymidine labelling in the cells of the epiphysial cartilage and metaphysis of the tibia in the rat is described for intervals of one hour to twenty-eight days after injection.
Journal ArticleDOI
Compensatory growth and sexual maturity in mice
L. S. Monteiro,D. S. Falconer +1 more
TL;DR: The effects of environmental factors in the pre-weaning period on the subsequent growth of mice were studied in this article, where it was found that the inflexion point separating the initial phase of exponential growth from the subsequent phase of asymptotic growth corresponded closely with the attainment of sexual maturity in females, as judged by the opening of the vagina.