Abstract
Calcium hydroxyapatite can be a significant component of black pigment gallstones. Diverse molecules that bind calcium phosphate inhibit hydroxyapatite precipitation. Because glycine-conjugated bile acids, but not their taurine counterparts, bind calcium phosphate, we studied whether glycochenodeoxycholic acid inhibits calcium hydroxyapatite formation. Glycochenodeoxycholic acid (2 mM) totally inhibited transformation of amorphous calcium phosphate microprecipitates to macroscopic crystalline calcium hydroxyapatite. This inhibition was not mediated by decreased Ca2+ activity. Taurocholic acid (2-12 mM) did not affect hydroxyapatite formation, but antagonized glycochenodeoxycholic acid. Both amorphous and crystalline precipitates contained a surface fraction relatively rich in phosphate. The surface phosphate content was diminished by increasing glycochenodeoxycholic acid concentrations, and this relationship was interpreted as competition between bile acid and HPO4 2- for binding sites on the calcium phosphate surface. A phosphate-rich crystal surface was associated with rapid transition from amorphous to crystalline states. These results indicate that glycochenodeoxycholic acid prevents transformation of amorphous calcium phosphate to crystalline hydroxyapatite by competitively inhibiting the accumulation of phosphate on the crystal embryo surface.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1265-1271 |
| Number of pages | 7 |
| Journal | Journal of Clinical Investigation |
| Volume | 88 |
| Issue number | 4 |
| State | Published - 1991 |
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Keywords
- Bile salts
- Biomineralization
- Calcification
- Fourier transform infrared spectroscopy
- Gallstones
ASJC Scopus subject areas
- Medicine(all)
Cite this
Glycochenodeoxycholic acid inhibits calcium phosphate precipitation in vitro by preventing the transformation of amorphous calcium phosphate to calcium hydroxyapatite. / Qiu, Suimin; Wen, Gary; Hirakawa, Nobuyuki; Soloway, Roger D.; Hong, Nan Kang; Crowther, Roger S.
In: Journal of Clinical Investigation, Vol. 88, No. 4, 1991, p. 1265-1271.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Glycochenodeoxycholic acid inhibits calcium phosphate precipitation in vitro by preventing the transformation of amorphous calcium phosphate to calcium hydroxyapatite
AU - Qiu, Suimin
AU - Wen, Gary
AU - Hirakawa, Nobuyuki
AU - Soloway, Roger D.
AU - Hong, Nan Kang
AU - Crowther, Roger S.
PY - 1991
Y1 - 1991
N2 - Calcium hydroxyapatite can be a significant component of black pigment gallstones. Diverse molecules that bind calcium phosphate inhibit hydroxyapatite precipitation. Because glycine-conjugated bile acids, but not their taurine counterparts, bind calcium phosphate, we studied whether glycochenodeoxycholic acid inhibits calcium hydroxyapatite formation. Glycochenodeoxycholic acid (2 mM) totally inhibited transformation of amorphous calcium phosphate microprecipitates to macroscopic crystalline calcium hydroxyapatite. This inhibition was not mediated by decreased Ca2+ activity. Taurocholic acid (2-12 mM) did not affect hydroxyapatite formation, but antagonized glycochenodeoxycholic acid. Both amorphous and crystalline precipitates contained a surface fraction relatively rich in phosphate. The surface phosphate content was diminished by increasing glycochenodeoxycholic acid concentrations, and this relationship was interpreted as competition between bile acid and HPO4 2- for binding sites on the calcium phosphate surface. A phosphate-rich crystal surface was associated with rapid transition from amorphous to crystalline states. These results indicate that glycochenodeoxycholic acid prevents transformation of amorphous calcium phosphate to crystalline hydroxyapatite by competitively inhibiting the accumulation of phosphate on the crystal embryo surface.
AB - Calcium hydroxyapatite can be a significant component of black pigment gallstones. Diverse molecules that bind calcium phosphate inhibit hydroxyapatite precipitation. Because glycine-conjugated bile acids, but not their taurine counterparts, bind calcium phosphate, we studied whether glycochenodeoxycholic acid inhibits calcium hydroxyapatite formation. Glycochenodeoxycholic acid (2 mM) totally inhibited transformation of amorphous calcium phosphate microprecipitates to macroscopic crystalline calcium hydroxyapatite. This inhibition was not mediated by decreased Ca2+ activity. Taurocholic acid (2-12 mM) did not affect hydroxyapatite formation, but antagonized glycochenodeoxycholic acid. Both amorphous and crystalline precipitates contained a surface fraction relatively rich in phosphate. The surface phosphate content was diminished by increasing glycochenodeoxycholic acid concentrations, and this relationship was interpreted as competition between bile acid and HPO4 2- for binding sites on the calcium phosphate surface. A phosphate-rich crystal surface was associated with rapid transition from amorphous to crystalline states. These results indicate that glycochenodeoxycholic acid prevents transformation of amorphous calcium phosphate to crystalline hydroxyapatite by competitively inhibiting the accumulation of phosphate on the crystal embryo surface.
KW - Bile salts
KW - Biomineralization
KW - Calcification
KW - Fourier transform infrared spectroscopy
KW - Gallstones
UR - http://www.scopus.com/inward/record.url?scp=0026018071&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0026018071&partnerID=8YFLogxK
M3 - Article
VL - 88
SP - 1265
EP - 1271
JO - Journal of Clinical Investigation
JF - Journal of Clinical Investigation
SN - 0021-9738
IS - 4
ER -