Bones components

In addition to its role as a bone component, calcium functions as a signaling substance. Ca "" ions act as second messengers in signal transduction pathways (see p. 386), they trigger exocytosis (see p. 228) and muscle contraction (see p. 334), and they are indispensable as cofactors in blood coagulation (see p. 290). Many enzymes also require Ca "" for their activity. The intracellular and extracellular concentrations of Ca "" are strictly regulated in order to make these functions possible (see B, C, and p.388). 

Structure of Bone Components and their Model Compounds.238... 

Kaflak-Hachulska A, Zlotkowska A, Kolodziejski W (1999) Infrared stndy of hydroxylic groups in human bone and bone components. In Materials of Vth International Conference on Molecular Spectroscopy from Molecules to Molecular Biological Systems and Molecular Materials Role of Molecular Interactions and Recognition. Wroclaw-Ladek Zdrdj, Poland... 

Kolodziejski W, Kaflak-Hachulska A (1999) Proton MAS NMR studies of human hone and bone components. In Materials of the Alpine Conference on Sohd-State NMR. Chamonix - Mont Blanc, France... 

Most of the studies before 1965 were unable to make a clear-cut distinction between liver and bone components, since they frequently overlap with each other because of a subtle difference in the rate of their... 

The above considerations are not incompatible with the likelihood that liver and bone may be sources of alkaline phosphatase in the normal individual, but make it very probable that their contributions are relatively minor indeed compared to intestine. Moreover, since the varieties of unmodified and modified intestinal alkaline phosphatases have among them all the properties that have been employed to identify liver and bone components of serum alkaline phosphatase in biochemical and starch-gel experiments, the interpretation of enzyme bands in the nonpregnant individual must be stated as intestine plus liver (H17) or intestine plus bone (R20) and not liver or bone. ... 

In fact in experimental animals (rat), rickets produced by avitaminosis D results in hyperphosphatasemia (F12) [normal 6.19 units/100 ml (Fll), rickets 17.9 units/100 ml], that results from both "intestinal and bone components [see also (D21) and R20)]. 

The use of polarized light to generate contrast between bone components provides information on the spatial distribution of bone components and their orientation. Kazanci et al. used Raman polarized imaging to examine the distribution of mineral and matrix constituents around osteons, and showed that the POi Vi and amide I bands are highly orientation-dependent, whereas the amide III and POi V2 and V4 are less orientation-dependent [35]. Orientation effects are nicely illustrated in Figure 4.2 [36]. The POi Vj amide I ratio coincides with the orientation of the lamellae the same lamellae have different contrasts, depending on the polarization of the excitation light and the orientation of the specimen. 

The effect of the fractionated extracts obtained from S. homeri on bone calcium content and osteoclast-like cell formation in vitro has also been investigated. The effects of S. horneri on bone components in the femoral diaphyseal and metaphyseal tissues of yoimg and aged rats were studied. The oral intake of the water-solubilized S. homeri extract significantly altered the bone components of yoimg rats in vivo (Uchiyama and Yamaguchi, 2002 Uchiyama et ah, 2004). 

Uchiyama, S. and Yamaguchi, M. (2002). Anabolic effect of marine alga Sargassum horneri extract on bone components in the femoral-diaphyseal and -metaphyseal tissues of young and aged rats in vivo. /. Health Sci. 48,325-330. 

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