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.

Role of prolactin in vitamin D metabolism and calcium absorption during lactation in the rat

1982 ◽  
Vol 94 (3) ◽  
pp. 443-453 ◽  
Author(s):  
C. J. Robinson ◽  
E. Spanos ◽  
M. F. James ◽  
J. W. Pike ◽  
M. R. Haussler ◽  
...  
Keyword(s):  
Vitamin D ◽  
Alkaline Phosphatase ◽  
Parathyroid Hormone ◽  
Alkaline Phosphatase Activity ◽  
Plasma Levels ◽  
Calcium Absorption ◽  
High Plasma ◽  
Intestinal Calcium Absorption ◽  
Vitamin D Metabolism

Intestinal calcium absorption and plasma levels of 1,25-dihydroxycholecalciferol (1,25(OH)2D3) were measured in lactating and non-lactating rats and the effects of bromocriptine and exogenous prolactin treatment were evaluated. In lactating rats calcium absorption and plasma levels of parathyroid hormone, 1,25(OH)2D3 and alkaline phosphatase activity were significantly increased. Bromocriptine treatment significantly reduced the enhanced calcium absorption and levels of plasma 1,25(OH)2D3 and alkaline phosphatase but had no significant effect on plasma levels of parathyroid hormone. Prolactin administered with bromocriptine to lactating animals prevented all the changes observed with bromocriptine treatment alone. It was concluded that the increased plasma levels of prolactin during lactation lead to high plasma levels of 1,25(OH)2D3 which are responsible for the enhanced intestinal calcium absorption.

Different Dietary Calcium Intake and Relative Supersaturation of Calcium Oxalate in the Urine of Patients Forming Renal Stones

1997 ◽  
Vol 93 (3) ◽  
pp. 257-263 ◽  
Author(s):  
Piergiorgio Messa ◽  
Martino Marangella ◽  
Luisa Paganin ◽  
Mara Codardini ◽  
Aldo Cruciatti ◽  
...  
Keyword(s):  
Parathyroid Hormone ◽  
Calcium Oxalate ◽  
Calcium Absorption ◽  
Dietary Calcium ◽  
Calcium Excretion ◽  
Soluble Complex ◽  
Complex Species ◽  
Calcium Diet ◽  
Low Calcium Diet ◽  
Low Calcium

1. Dietary calcium restriction, an efficient practice in reducing urinary calcium excretion, has been reported to induce either an increase or no change in oxalate excretion, questioning its use in hypercalciuric stone-forming patients. In addition, calcium restriction has been previously demonstrated to induce other urinary changes which might influence the relative supersaturation of calcium oxalate. So the overall effect of calcium deprivation on the relative supersaturation of calcium oxalate is unpredictable. 2. The aim of the study was to evaluate the effect of dietary calcium restriction on the relative supersaturation of calcium oxalate in the urine of stone-forming patients utilizing a computer methodology which takes into account the main soluble complex species of oxalate. 3. We studied 34 stone-forming patients on both a free-choice diet, whose Ca and oxalate content (24 and 1.2 mmol respectively) was assessed by dietary inquiry, and after 30 days on a prescribed low-calcium and normal oxalate diet (11 and 1.1 mmol respectively). Under both conditions, the excretion of the main urinary parameters related to dietary composition, electrolytes, oxalate and daily citrate urinary excretion, were measured. The relative supersaturation of calcium oxalate was calculated by means of an iterative computer method which takes into account the main soluble complex species on which the solubility of calcium oxalate is dependent. In addition, intact parathyroid hormone and 1,25-dihydroxyvitamin D blood levels were also evaluated. In 13 of the patients intestinal calcium absorption was evaluated during both a free- and a low-calcium diet, utilizing kinetics methodology. 4. The low-calcium diet induced, together with an expected reduction of calcium excretion, a marked increase in oxalate urinary output. This finding was independent of the presence or otherwise of hypercalciuria and of the serum levels of parathyroid hormone and vitamin D. Intestinal calcium absorption was also stimulated by calcium deprivation and its levels were well correlated with oxalate excretion. Minor changes in magnesium and citrate excretion were also observed. The overall effect on the relative supersaturation of calcium oxalate consisted in a substantial increase in this parameter during the low-calcium diet. 5. In conclusion, our data reinforce the concept that dietary calcium restriction has potentially deleterious effects on lithogenesis, by increasing the relative supersaturation of calcium oxalate.

ROLE OF THE PARATHYROID GLANDS IN THE ENHANCEMENT OF INTESTINAL CALCIUM ABSORPTION IN RESPONSE TO A LOW CALCIUM DIET

1977 ◽  
Vol 74 (3) ◽  
pp. 345-354 ◽  
Author(s):  
J. FOX ◽  
R. SWAMINATHAN ◽  
T. M. MURRAY ◽  
A. D. CARE
Keyword(s):  
Small Intestine ◽  
Calcium Binding ◽  
Calcium Absorption ◽  
Binding Protein ◽  
Calcium Binding Protein ◽  
Intestinal Calcium Absorption ◽  
Parathyroid Glands ◽  
Calcium Diet ◽  
Low Calcium Diet ◽  
Low Calcium

SUMMARY The phenomenon of adaptation of intestinal calcium absorption to changes in dietary calcium has been studied in conscious pigs with Thiry–Vella jejunal loops. The result of decreasing the calcium content of the diet from 1·2 to 0·1% was an increase in the efficiency of the net absorption of calcium from the fluid used to perfuse the jejunal loop; this increase took place 4–6 days after the change in diet. A similar effect was noted in four pigs which had previously been parathyroidectomized and in two thyroparathyroidectomized pigs with thyroxine replacement therapy. The effect seen in the parathyroidectomized animals was not attributable to an increase in the concentration gradient of calcium ions between the jejunal lumen and the blood after the change to the low calcium diet. There was a marked increase in the amount of calcium-binding protein in the mucosa taken from the distal three-quarters of the small intestine of intact pigs fed a low calcium diet. However, after parathyroidectomy, the level of calcium in the diet had no significant effect on the amount of calcium-binding protein in the small intestine. It is concluded that, in pigs, neither parathyroid hormone nor calcitonin is necessary for intestinal adaptation to a low calcium diet and that, although this adaptation may be mediated by 1,25-dihydroxycholecalciferol, a significant increase in the level of calcium-binding protein in the intestine is only seen when the parathyroid glands are intact.

Effect of a low-calcium environment on alkaline phosphatase activity in embryonic rat calvarial bone cells in culture

1996 ◽  
Vol 41 (1) ◽  
pp. 41-45 ◽  
Author(s):  
Yoshitaka Yoshimura ◽  
Yoh Hisada ◽  
Kuniaki Suzuki ◽  
Yoshiaki Deyama ◽  
Akira Matsumoto
Keyword(s):  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Bone Cells ◽  
Calvarial Bone ◽  
Cells In Culture ◽  
Low Calcium

LEUCOCYTE METABOLISM IN PREGNANCY

1960 ◽  
Vol XXXV (IV) ◽  
pp. 575-584 ◽  
Author(s):  
C. Borel ◽  
J. Frei ◽  
A. Vannotti
Keyword(s):  
Alkaline Phosphatase ◽  
Oxygen Consumption ◽  
Pregnant Women ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Lactate Production ◽  
Glucose Consumption ◽  
In Pregnancy

ABSTRACT Enzymatic studies, on leucocytes of pregnant women, show an increase of the alkaline phosphatase activity and a decrease of the glucose consumption and lactate production, as well as of proteolysis. The oxygen consumption, with succinate as substrate, does not vary.

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