Parathyroid hormone stimulates growth of embryonic chick pelvic cartilagein vitro

Lethal skeletal dysplasia from targeted disruption of the parathyroid hormone-related peptide gene.

“…Similarly, a proliferative abnormality may contribute to the diminished size of the early cartilaginous rudiments, as well. This proliferative abnormality observed in vivo may well correlate with in vitro findings that amino-terminal fragments of PTH promote proliferation of fetal growth plate chondrocytes (Koike et al 1990;Burch and Lebovitz 1983). Second, in the absence of PTHrP, chondrocytes differentiate prematurely.…”

Potent mitogenic effects of parathyroid hormone (PTH) on embryonic chick and rabbit chondrocytes. Differential effects of age on growth, proteoglycan, and cyclic AMP responses of chondrocytes to PTH.

“…This finding indicates that PTH stimulation of chondrocyte phenotypic expression is not linked to its growth stimulation, and that the mitogenic action of PTH is not mediated by cAMP. The effects of cAMP analogue mimicked those of PTH in chondrocytes (5,8,9,29,30), but dibutyryl cAMP enhanced chondrocyte growth (8,9,30) (32). Furthermore, PTH is found in fetal blood of various animals, and its level (10-'1-10-'0 M) is similar to the maternal level (monkey [33]; miniature pig [34]; rabbit [Kato, Y., and T. Koike, unpublished observations]).…”

“…This increase in [35S]sulfate incorporation was due to enhanced synthesis of large, chondroitin sulfate proteoglycans, the main component of cartilage matrix (3,4). PTH also increased the cAMP level 50-fold (4-6) and the ornithine decarboxylase activity 5-fold (5, 7) in 4-to 7-wk-old rabbit costal chondrocytes in mono-other hand, there are reports that PTH caused a 1.5-to 2-fold increase in the length, weight, and DNA content of embryonic 9-d-old chicken femur and pelvic cartilage in organ culture (8,9). A 1.5-fold increase by PTH in [3H]thymidine uptake was also noted in embryonic cartilage (9).…”

“…PTH also increased the cAMP level 50-fold (4-6) and the ornithine decarboxylase activity 5-fold (5, 7) in 4-to 7-wk-old rabbit costal chondrocytes in mono-other hand, there are reports that PTH caused a 1.5-to 2-fold increase in the length, weight, and DNA content of embryonic 9-d-old chicken femur and pelvic cartilage in organ culture (8,9). A 1.5-fold increase by PTH in [3H]thymidine uptake was also noted in embryonic cartilage (9). These conflicting observations about the mitogenic action of PTH can be explained by supposing that the mitogenic action of PTH is dependent on cartilage age.…”

Slipped capital femoral epiphysis associated with hyperparathyroidism

“…Parathormone (PTH) has been reported to stimulate embryonic chick pelvic cartilage growth and the increase of growth was dependent on PTH concentration in the medium [3]. It has also been reported that PTH inhibited calcification in rabbit growth-plate chondrocyte culture [6].…”