Positive interaction between 17β-estradiol and parathyroid hormone in normal human osteoblasts cultured long term in the presence of dexamethasone

1996 ◽  
Vol 6 (2) ◽  
pp. 111-119 ◽  
Author(s):  
L. G. Rao ◽  
M. S. Kung Sutherland ◽  
S. A. Muzaffar ◽  
J. N. Wylie ◽  
R. J. McBroom ◽  
...  
1991 ◽  
Vol 274 (1) ◽  
pp. 15-20 ◽  
Author(s):  
C Schöfl ◽  
K S R Cuthbertson ◽  
J A Gallagher ◽  
S R Pennington ◽  
P H Cobbold ◽  
...  

It is known that parathyroid hormone (PTH) activates the cyclic AMP (cAMP) signalling pathway in osteoblasts. In recent years it has been suggested that an elevation of the intracellular free Ca2+ concentration ([Ca2+]i) may also be involved in the regulation of osteoblast function by PTH. However, this remains controversial. Here we investigated the effect of PTH on the [Ca2+]i of ROS 17/2.8 cells and normal human osteoblasts. The [Ca2+]i was measured in single aequorin-injected cells and in suspensions of cells loaded with fura-2. Human PTH-(1-38)-peptide (1-300 nM) had no effect on the [Ca2+]i in single aequorin-injected ROS 17/2.8 cells (n = 17) measured at various times after injection (1-20 h), or in suspensions of fura-2-loaded ROS 17/2.8 cells (n = 9). Ionomycin (1 microM) increased the [Ca2+]i in fura-2-loaded and single aequorin-injected ROS 17/2.8 cells by 285 +/- 60 nM (n = 9) and 312 +/- 99 nM (n = 6) respectively, indicating that both methods detect changes in [Ca2+]i with equal sensitivity. In contrast, human PTH-(1-38) (10-100 nM) markedly stimulated cAMP accumulation in ROS 17/2.8 cells. In single aequorin-injected normal human osteoblasts there was no change in the [Ca2+]i in response to 100 nM human PTH-(1-38) or 100 nM bovine PTH-(1-84) (n = 18). In contrast, in suspensions of normal human osteoblasts loaded with fura-2, an increase in [Ca2+]i in response to human PTH-(1-38) (100 nM) was found (60 +/- 28 nM; n = 6). Considerable variation in the magnitude of the response was observed between individual preparations and donors. These data indicate that PTH activates cAMP accumulation without affecting [Ca2+]i in ROS 17/2.8 cells and that PTH causes a rise in [Ca2+]i only in a small subset of normal human osteoblasts. We suggest that the Ca2+ response to PTH in osteoblasts is limited by the state of differentiation of the cells, and may be due either to the presence of a distinct Ca2(+)-mobilizing receptor or to a cAMP-mediated Ca2+ response.


1995 ◽  
Vol 5 (5) ◽  
pp. 335-343 ◽  
Author(s):  
M. S. Kung Sutherland ◽  
L. G. Rao ◽  
S. A. Muzaffar ◽  
J. N. Wylie ◽  
M. M. Wong ◽  
...  

Endocrinology ◽  
1991 ◽  
Vol 129 (6) ◽  
pp. 3313-3320 ◽  
Author(s):  
MERRY JO OURSLER ◽  
CASE CORTESE ◽  
PHILIP KEETING ◽  
MARLYS A. ANDERSON ◽  
SUSAN K. BONDE ◽  
...  

1996 ◽  
Vol 351 (1346) ◽  
pp. 1455-1462 ◽  

The lateral frontal cortex is involved in various aspects of executive processing within short- and long-term memory. It is argued that the different parts of the lateral frontal cortex make distinct contributions to memory that differ in terms of the level of executive processing that is carried out in interaction with posterior cortical systems. According to this hypothesis, the mid-dorsolateral frontal cortex (areas 46 and 9) is a specialized system for the monitoring and manipulation of information within working memory, whereas the mid-ventrolateral frontal cortex (areas 47/12 and 45) is involved in the active retrieval of information from the posterior cortical association areas. Data are presented which support this two-level hypothesis that posits two distinct levels of interaction of the lateral frontal cortex with posterior cortical association areas. Functional activation studies with normal human subjects have demonstrated specific activity within the mid-dorsolateral region of the frontal cortex during the performance of tasks requiring monitoring of self-generated and externally generated sequences of responses. In the monkey, lesions restricted to this region of the frontal cortex yield a severe impairment in performance of the above tasks, this impairment appearing against a background of normal performance on several basic mnemonic tasks. By contrast, a more severe impairment follows damage to the mid-ventrolateral frontal region and functional activation studies have demonstrated specific changes in activity in this region in relation to the active retrieval of information from memory.


2021 ◽  
Vol 11 (11) ◽  
pp. 5268
Author(s):  
Zohaib Khurshid ◽  
Faris Yahya Asiri

Objective: The aim of this review is to summarize the effects of local and systemic PTH administration on periodontal tissues during orthodontic tooth movement. Materials and methods: An electronic search was conducted on the following databases: PubMed/MEDLINE, Google Scholar, SCOPUS and Embase. On PubMed/MEDLINE, the Medical Subject Headings (MeSH) keywords used were: “orthodontic tooth movement” OR (“tooth” (All Fields) AND “tooth movement” (All Fields)) OR “tooth movement” (All Fields)) AND (“parathyroid hormone”); all studies included using CONSORT. Results: After elimination of duplicates and articles not meeting our inclusion criteria, seven animal studies were included in this review. Although the majority of the studies suggest that PTH may a have a favorable outcome on OTM, most studies were found to have several sources of bias. Conclusion: Animal studies with minimal bias and long-term clinical studies are needed to ascertain the efficacy of intermittent PTH administration in improving the rate and retention of OTM.


1978 ◽  
Vol 88 (3) ◽  
pp. 528-534 ◽  
Author(s):  
C. Christiansen ◽  
P. C. Baastrup ◽  
P. Lindgreen ◽  
I. Transbøl

ABSTRACT Ninety-six manic-depressive patients were studied during long-term lithium treatment. Highly significant elevations were observed respecting the levels of serum immunoreactive parathyroid hormone (P < 0.001) as well as the protein-corrected levels of serum calcium (P < 0.001) and serum magnesium (P <0.001), thus indicating a state of 'primary' hyperparathyroidism. The patients as a group had normophosphataemia and normophosphatasia supporting the impression of a rather mild state of biochemical hyperparathyroidism.


2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Anna Magiera ◽  
Jarosław Markowski ◽  
Elzbieta Menaszek ◽  
Jan Pilch ◽  
Stanislaw Blazewicz

The aim of the study was to manufacture poly(lactic acid)- (PLA-) based nanofibrous nonwovens that were modified using two types of modifiers, namely, gelatin- (GEL-) based nanofibres and carbon nanotubes (CNT). Hybrid nonwovens consisting of PLA and GEL nanofibres (PLA/GEL), as well as CNT-modified PLA nanofibres with GEL nanofibres (PLA + CNT/GEL), in the form of mats, were manufactured using concurrent-electrospinning technique (co-ES). The ability of such hybrid structures as potential scaffolds for tissue engineering was studied. Both types of hybrid samples and one-component PLA and CNTs-modified PLA mats were investigated using scanning electron microscopy (SEM), water contact angle measurements, and biological and mechanical tests. The morphology, microstructure, and selected properties of the materials were analyzed. Biocompatibility and bioactivity in contact with normal human osteoblasts (NHOst) were studied. The coelectrospun PLA and GEL nanofibres retained their structures in hybrid samples. Both types of hybrid nonwovens were not cytotoxic and showed better osteoinductivity in comparison to scaffolds made from pure PLA. These samples also showed significantly reduced hydrophobicity compared to one-component PLA nonwovens. The CNT-contained PLA nanofibres improved mechanical properties of hybrid samples and such a 3D system appears to be interesting for potential application as a tissue engineering scaffold.


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