Effect of dietary calcium: Phosphorus ratio on bone mineralization and intestinal calcium absorption in ovariectomized rats

BioFactors ◽  
2004 ◽  
Vol 22 (1-4) ◽  
pp. 39-42 ◽  
Author(s):  
Moyuru Koshihara ◽  
Ritsuko Masuyama ◽  
Mariko Uehara ◽  
Kazuharu Suzuki
Keyword(s):  
Calcium Absorption ◽  
Bone Mineralization ◽  
Dietary Calcium ◽  
Intestinal Calcium Absorption ◽  
Ovariectomized Rats ◽  
Calcium Phosphorus

Action of 1,25-dihydroxyvitamin D3 and a diphosphonate on calcium metabolism in rats

1975 ◽  
Vol 229 (2) ◽  
pp. 402-408 ◽  
Author(s):  
JP Bonjour ◽  
U Trechsel ◽  
H Fleisch ◽  
R Schenk ◽  
HF DeLuca ◽  
...  
Keyword(s):  
Calcium Metabolism ◽  
Calcium Absorption ◽  
Bone Mineralization ◽  
Concomitant Administration ◽  
Urinary Calcium ◽  
Intestinal Calcium Absorption ◽  
Bone Morphology ◽  
Dihydroxyvitamin D3 ◽  
Calcium Retention ◽  
Endogenous Production

The effect of 1,25-dihydroxycholecalciferol (1,25-(OH)2D3) on Ca balance, 45Ca kinetics, and bone morphology has been studied in control rats and rats given disodium ethane-1-hydroxy-1,1-diphosphonate (EHDP), 10 mg P/kg sc per day. This large dose of EHDP is known to inhibit bone mineralization and intestinal calcium absorption and to depress the endogenous production of 1,25-(OH)2D3. In conctrol rats, 1,25-(OH)2D3 increased intestinal calcium absorption. However, in contrast to the enhanced calcium absorption that results from an augmentation of dietary calcium, the 1,25(OH)2D3-induced augmentation of calcium absorption does not lead to a rise in calcium retention, the intestinal effect being matched by an increased excretion of urinary calcium. The EHDP-induced decrease of intestinal calcium absorption could be completely prevented by the concomitant administration of 1,25-(OH)2D3 but not the inhibition of bone mineralization. Therefore, in contrast to the impairment of calcium absorption, that of bone mineralization brought about by large doses of EHDP cannot be merely attributed to a decreased production of 1,25-(OH)2D3.

Relation between bone mineralization, Ca absorption, and plasma Ca in phosphonate-treated rats.

1977 ◽  
Vol 232 (3) ◽  
pp. E298
Author(s):  
U Trechsel ◽  
R Schenk ◽  
J P Bonjour ◽  
R G Russell ◽  
H Fleisch
Keyword(s):  
Calcium Absorption ◽  
Bone Mineralization ◽  
Close Correlation ◽  
Plasma Calcium ◽  
Intestinal Calcium Absorption ◽  
Phosphate Salts ◽  
Dose Response Study ◽  
Skeletal Mineralization

Disodium ethane-1-hydroxy-1,1-diphosphonate (EHDP) is known to inhibit the crystallization of calcium phosphate salts in vitro. Large doses of EHDP administered in vivo inhibit skeletal mineralization, decrease intestinal calcium absorption, and produce hypercalcemia. In the present study, EHDP or one of 13 other phosphonates were given to rats at 10 mg P/kg-day sc for 7 days in order to better define the nature of the relationship between bone mineralization, intestinal absorption, and plasma calcium in the regulation of calcium homeostasis. Each of the phosphonates which inhibited skeletal mineralization in vivo also inhibited crystallization in vitro, but the converse was not true. A very close correlation was found between inhibition of skeletal mineralization, decreased intestinal calcium absorption, and slight hypercalcemia. A dose-response study with two compounds also revealed the same close correlation. It is argued that the impairment of intestinal calcium absorption in phosphonate-treated rats may represent a secondary homeostatic response to the primary effect of the drugs on bone mineralization. This response may be mediated by an elevation of a fraction of plasma calcium.

Effect of age on intestinal calcium absorption and adaptation to dietary calcium.

1979 ◽  
Vol 236 (6) ◽  
pp. E769 ◽  
Author(s):  
H J Armbrecht ◽  
T V Zenser ◽  
M E Bruns ◽  
B B Davis
Keyword(s):  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Active Transport ◽  
Alkaline Phosphatase Activity ◽  
Calcium Absorption ◽  
Intestinal Adaptation ◽  
Dietary Calcium ◽  
Intestinal Calcium Absorption ◽  
Calcium Diet ◽  
Low Calcium

To study the reported decline in intestinal calcium absorption with age, calcium active transport, immunoreactive calcium protein (CaBP) content, and alkaline phosphatase activity were measured in the intestine of two strains of rats aged 3-wk--20 mo. Calcium active transport, as measured by everted gut sacs from Sprague-Dawley rats, was greatest at 3 wk, but it declined rapidly with no active transport demonstrable at 3 mo or thereafter. CaBP content closely paralleled the decline in active transport, but alkaline phosphatase activity increased as active transport decreased. Intestinal adaptation to dietary calcium was studied by feeding high- and low-calcium diets to Fischer 344 rats aged 1.5--12 mo. In 1.5-mo-old rats fed a low-calcium diet, there was an increase in calcium active transport, CaBP content, and alkaline phosphatase activity relative to animals fed a high-calcium diet. However, the magnitude of this intestinal adaptation decreased with age until there was only marginal adaptation by 12 mo. The observed changes in calcium active transport with age and diet may be explained by the parallel changes in the vitamin D-dependent CaBP content of the intestine.

Reduction in Dietary Calcium/Phosphorus Ratio Reduces Bone Mass and Strength in Ovariectomized Rats Enhancing Bone Turnover

2005 ◽  
Vol 69 (10) ◽  
pp. 1970-1973 ◽  
Author(s):  
Moyuru KOSHIHARA ◽  
Ritsuko MASUYAMA ◽  
Mariko UEHARA ◽  
Kazuharu SUZUKI
Keyword(s):  
Bone Mass ◽  
Bone Turnover ◽  
Dietary Calcium ◽  
Ovariectomized Rats ◽  
Calcium Phosphorus

Calcium Absorption and Bone Loss in Ovariectomized Rats Fed Varying Levels of Dietary Calcium

1999 ◽  
Vol 65 (1) ◽  
pp. 73-77 ◽  
Author(s):  
D. N. Kalu ◽  
P. B. Orhii
Keyword(s):  
Bone Loss ◽  
Calcium Absorption ◽  
Dietary Calcium ◽  
Ovariectomized Rats
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