Degree of saturation of blood plasma in vertebrates with octocalcium phosphate

1988 ◽  
Vol 43 (1-2) ◽  
pp. 74-76 ◽  
Author(s):  
F. C. M. Driessens ◽  
R. M. H. Verbeeck ◽  
J. W. E. van Dijk ◽  
J. M. P. M. Borggreven

In previous papers it has been shown that octocalcium phospate OCP occurs in bone mineral of vertebrates. Although this compound is not stable, there is a continuous new-formation of OCP due to bone turnover. Literature data of the calcium and phosphate concentrations in the blood plasma of vertebrates were collected and the degree of saturation with OCP was calculated. The results show that blood plasma of vertebrates is almost saturated with OCP. This fact indicates that OCP is the solubility controlling phase in the mineral of vertebrates. Further it verifies the expectation based on physicochemical theory that the interaction between body fluids and bone mineral is important in the calcium and phosphate homeostasis

2014 ◽  
Author(s):  
Mingo Dominguez Maria Luisa de ◽  
Sonsoles Guadalix Iglesias ◽  
Maria Begona Lopez Alvarez ◽  
Guillermo Martinez Diaz-Guerra ◽  
Federico Hawkins Carranza

2020 ◽  
Author(s):  
Lungwani Muungo

Although it is well established that estrogen deficiencycauses osteoporosis among the postmenopausalwomen, the involvement of estrogen receptor (ER) in itspathogenesis still remains uncertain. In the presentstudy, we have generated rats harboring a dominantnegative ERa, which inhibits the actions of not only ERabut also recently identified ERb. Contrary to our expectation,the bone mineral density (BMD) of the resultingtransgenic female rats was maintained at the same levelwith that of the wild-type littermates when sham-operated.In addition, ovariectomy-induced bone loss wasobserved almost equally in both groups. Strikingly, however,the BMD of the transgenic female rats, after ovariectomized,remained decreased even if 17b-estradiol(E2) was administrated, whereas, in contrast, the decreaseof littermate BMD was completely prevented byE2. Moreover, bone histomorphometrical analysis ofovariectomized transgenic rats revealed that the higherrates of bone turnover still remained after treatmentwith E2. These results demonstrate that the preventionfrom the ovariectomy-induced bone loss by estrogen ismediated by ER pathways and that the maintenanceof BMD before ovariectomy might be compensatedby other mechanisms distinct from ERa and ERbpathways.


2019 ◽  
Vol 17 (4) ◽  
pp. 102-106
Author(s):  
M. Yu. Smetanin ◽  
◽  
S. Yu. Nurgalieva ◽  
N. Yu. Kononova ◽  
L. T. Pimenov ◽  
...  

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