Comparison of the effects of a potent synthetic analog of bovine parathyroid hormone with native bPTH-(1-84) and synthetic bPTH-(1-34) on bone resorption and collagen synthesis

Raisz, Lawrence G.; Lorenzo, Joseph; Gworek, Susan C.; Kream, Barbara E.; Rosenblatt, Michael

doi:10.1007/bf02408083

Cited by 37 publications

(7 citation statements)

References 7 publications

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“…We found increased bone resorption in response to a physiologic dose (1 pM) of PTH (or 0.3 milliunit of PTE per ml). Studies by others utilized much higher concentrations ofPTE (0.5 unit/ ml) or PTH (0.1 unit/ml) to obtain bone resorption in vitro (25,26). With 1 pM PTE we observed an acute inhibition of bone formation followed by a chronic enhancement of bone formation; higher concentrations ofPTE (0.01-1 nM) caused a chronic inhibition of bone formation (Fig.…”

Section: Discussionmentioning

confidence: 78%

See 1 more Smart Citation

Parathyroid hormone stimulates bone formation and resorption in organ culture: evidence for a coupling mechanism.

Howard¹,

Bottemiller²,

Turner³

et al. 1981

Proc. Natl. Acad. Sci. U.S.A.

231

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We have developed an in vitro system, using embryonic chicken tibiae grown in a serum-free medium, which exhibits simultaneous bone formation and resorption. Tibiae from 8-day embryos increased in mean (±SD) length (4.0 ± 0.4 to 11.0 ± 0.3 mm) and dry weight (0.30 ± 0.04 to 0.84 ± 0.04 mg) during 12 days in vitro. There was increased incorporation of [3H]proline into hydroxyproline (120 ± 20 to 340 ± 20 cpm/mg of bone per 24 hr) as a measure of collagen synthesis, as well as a 62 ± 5% increase in total calcium and 45Ca taken up as an indication of active mineralization. A physiologic concentration (1 pM) of parathyroid hormone was found to stimulate bone resorption over control levels in this system. Parathyroid hormone stimulated the release of [3H]hydroxyproline from the bone shafts but not from the cartilage ends, indicating the specificity of theresponse. With 1 pM parathyroid hormone we observed an acute inhibition of bone formation, followed (after 12-16 hr) by a chronic stimulation of bone formation during the 12-day incubation. Both mineral uptake and matrix formation were enhanced at approximately the same rate during the 12-day incubation. The chronic enhancement of formation required parathyroid hormone only for the initial 8-10 hr of incubation. These results could be explained by the production or release ofa factor from bone to stimulate formation in response to the acute increase in resorption-a "coupling factor." Indeed, dialyzed culture medium conditioned by actively resorbing bones stimulated bone formation over controls when added to organ cultures at a 1:20 dilution. The factor is larger than 12,000 daltons as determined by dialysis. The factor is specific for the bone shaft and did not affect the cartilage ends. Work directed toward a better understanding of the regulation of bone metabolism has shown that bone formation and bone resorption are coupled in vivo (1). This coupling occurs even in some disease states (e.g., hyper-and hypoparathyroidism, Paget disease, and acromegaly) (2). Detailed knowledge of the regulatory mechanism of coupling could lead to better understanding of the problems of metabolic bone disease. Studies toward this end from our laboratory have in the past relied predominantly on in vivo experiments (3,4). Although a large number of investigators have examined bone metabolism in vitro (5-9), none of these studies involved a chemically defined system in which simultaneously enhanced bone formation and resorption could be demonstrated. We have developed such an in vitro system and describe the details herein.We have utilized this coupled system to study the effects of parathyroid hormone (PTH) on bone metabolism in vitro in an attempt to clarify what appears to be a disagreement in the literature concerning these effects. The acute effect in vivo is reported to be the stimulation of bone resorption and inhibition of bone formation (10,11). Chronic in vivo treatment of young growing rats with PTH results in an increase in formation and resorption (4) and a net ga...

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Section: Discussionmentioning

confidence: 78%

“…Others have reported that fragment 1-34 PTH was capable of producing the same effects on bone as bovine PTH 1-84, suggesting that the total PTH molecule is unnecessary for its activity on bone (26,27).…”

Section: Discussionmentioning

confidence: 99%

Parathyroid hormone stimulates bone formation and resorption in organ culture: evidence for a coupling mechanism.

Howard¹,

Bottemiller²,

Turner³

et al. 1981

Proc. Natl. Acad. Sci. U.S.A.

231

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“…Parathyroid hormone (PTH) was shown to stimulate cyclic AMP (cAMP) accumulation in bone-derived cells believed to be osteoblasts [1,2] and to inhibit several osteoblast-associated functions including alkaline phosphatase activity [1,3,4] and collagen synthesis [5,6]. The relationship of cAMP elevation to the other PTH effects is yet to be established [7].…”

Section: Methodsmentioning

confidence: 98%

Alkaline phosphatase inhibition by parathyroid hormone and isoproterenol in a clonal rat osteosarcoma cell line. Possible mediation by cyclic AMP

1982

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The effect of parathyroid hormone (PTH 1-34 bovine) on alkaline phosphatase activity was investigated in an osteoblast-like clonal cell line derived from rat osteosarcoma (ROS 17/2). ROS 17/2 alkaline phosphatase resembled the bone enzyme in levamisole sensitivity and electrophoretic mobility but differed in heat stability. The specific activity of ROS 17/2 alkaline phosphatase increased with time in culture. This increase was inhibited by PTH (1-34) and (-)-isoproterenol in a dose-dependent manner starting at near-physiological hormone concentrations. The ID50 values were 0.02 nM for PTH (1-34) and 1.7 nM for isoproterenol. The two hormones stimulated ROS 17/2 adenylate cyclase, albeit at higher concentrations: Km values were 13 nM for PTH (1-34) and 16 nM for isoproterenol. The rise in alkaline phosphatase was also inhibited by dibutyryl cyclic AMP and 8-bromocyclic AMP (0.1 mM). These findings further document the osteoblastic properties of the ROS 17/2 osteosarcoma cell line, suggest that PTH inhibition of alkaline phosphatase represents a physiological response to the hormone in these cells, and implicate cyclic AMP as a mediator of this PTH effect.

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“…Incorporation of labeled proline into collagenase-digestible protein (CDP) versus incorporation into noticollagenous protein (NCP) was used as a measure of collagen synthesis. (25) The percentage collagen synthesis was calculated after multiplying the labeled proline in NCP by 5.4 to correct for its relative abundance in collagen. (1s) Third-passage, confluent cells were labeled for 24 h with 5…”

Section: Collagen Synthesismentioning

confidence: 99%

Effects of vitamin D metabolites on collagen production and cell proliferation of growth zone and resting zone cartilage cells in vitro

Schwartz

Schlader

Ramirez

et al. 1989

Journal of Bone and Mineral Research

130

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Previous studies have suggested that vitamin D metabolites directly influence the differentiation and maturation of chondrocytes in calcifying cartilage. Recently, this laboratory has shown that the response of chondrocyte plasma membrane and matrix vesicle enzymes to 1,25-(OH)2D3 and 24,25-(OH)2D3 is both cell and membrane specific. The current study demonstrates that cell replication and matrix protein synthesis are also modulated by vitamin D. Confluent, third-passage growth zone (GC) and resting zone (RC) costochondral chondrocytes were incubated in medium containing 10(-13)-10(-7) M 1,25-(OH)2D3 or 10(-12)-10(-6) M 24,25-(OH)2D3. The amount of collagenase-digestible protein (CDP) secreted into the media was inversely proportional to the concentration of fetal bovine serum (FBS). At 10% FBS, greater than 80% of the CDP was incorporated into the matrix. 1,25-(OH)2D3 stimulated CDP and percentage collagen synthesis by GC cells but had no effect on the synthesis of noncollagenous protein (NCP). 1,25-(OH)2D3 inhibited CDP and percentage collagen synthesis by RC cells but did not alter NCP synthesis. [3H]thymidine incorporation was inhibited in both cell types, whether confluent or subconfluent cultures were examined. At 10(-6) and 10(-7) M 24,25-(OH)2D3, there was a significant decrease in CDP production and percentage collagen synthesis by RC cells but no effect on NCP. However, at 10(-9) and 10(-10) M hormone there was an increase in NCP production but no effect on CDP, resulting in a decrease in percentage collagen synthesis. CDP and NCP production were unaffected by 24,25-(OH)2D3 in GC cells. High concentrations of hormone inhibited [3H]thymidine incorporation in both cell types.(ABSTRACT TRUNCATED AT 250 WORDS)

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Comparison of the effects of a potent synthetic analog of bovine parathyroid hormone with native bPTH-(1-84) and synthetic bPTH-(1-34) on bone resorption and collagen synthesis

Cited by 37 publications

References 7 publications

Parathyroid hormone stimulates bone formation and resorption in organ culture: evidence for a coupling mechanism.

Parathyroid hormone stimulates bone formation and resorption in organ culture: evidence for a coupling mechanism.

Alkaline phosphatase inhibition by parathyroid hormone and isoproterenol in a clonal rat osteosarcoma cell line. Possible mediation by cyclic AMP

Effects of vitamin D metabolites on collagen production and cell proliferation of growth zone and resting zone cartilage cells in vitro

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