DECREASED BONE SENSITIVITY OF THYROIDECTOMIZED RATS TO THE CALCAEMIC EFFECT OF 1,25-DIHYDROXYCHOLECALCIFEROL

1977 ◽  
Vol 84 (4) ◽  
pp. 774-779 ◽  
Author(s):  
H. Pavlovitch ◽  
V. Presle ◽  
S. Balsan
Keyword(s):  
Vitamin D ◽  
Single Dose ◽  
Serum Calcium ◽  
Calcium Concentration ◽  
Jugular Vein ◽  
Experimental Period ◽  
Normal Response ◽  
Serum Calcium Concentration ◽  
Low Calcium Diet ◽  
Intact Rats

ABSTRACT The calcaemic response of thyroidectomized parathyroid transplanted rats to a single dose of biosynthetic 1,25-dihydroxycholecalciferol (50 ng) injected into a jugular vein, was evaluated. The animals were fed a vitamin D-free, low calcium diet. Compared to sham-operated and to thyroidintact parathyroid transplanted rats thyroidectomized animals had a significantly reduced calcaemic response to 1,25-dihydroxycholecalciferol, Daily supplementation with d,l-thyroxine (100 μg/rat) during the experimental period restored a normal response. The increase in serum calcium concentration after 1,25-dihydroxycholecalciferol injection was similar in thyroidectomized bilaterally nephrectomized animals, and in thyroidectomized kidney-intact rats. The results suggest that in thyroxine depleted rats, the sensitivity of bone to the calcaemic effect of 1,25-dihydroxycholecalciferol is decreased.

scholarly journals Metabolites of vitamin D and minerals in blood and colostrum of primiparous and multiparous dairy cows postpartum 

2014 ◽  
Vol 59 (No. 1) ◽  
pp. 11-18
Author(s):  
E.G. Salgado-Hernández ◽  
J. Bouda ◽  
A. Villa-Godoy ◽  
J.L. Romano-Muñoz ◽  
A.J. Gutiérrez-Chávez ◽  
...  
Keyword(s):  
Vitamin D ◽  
Dairy Cows ◽  
Serum Calcium ◽  
Calcium Concentration ◽  
Inorganic Phosphorus ◽  
Normal Response ◽  
Serum Calcium Concentration ◽  
Blood Samples ◽  
Short Period ◽  
Baseline Values

Concentrations of calcidiol, calcitriol, and minerals in blood serum and colostrum of 14 primiparous and 16 multiparous Holstein dairy cows during short-period prepartum and postpartum were determined and compared. Blood samples were collected between days 5 and 2 prepartum and 6 h, 12 h, 7 and 21 days postpartum. Nearly 66% of primiparous and 71% of multiparous cows had subclinical postpartum hypocalcemia. Prepartum serum calcium (Ca) and inorganic phosphorus (P) were higher in primiparous cows; Ca decreased in both groups at 6 and 12 h and returned to baseline values 7 days postpartum. Calcidiol and calcitriol concentrations were equal on day 5 prepartum in both groups. In multiparous cows, calcidiol and calcitriol concentration increased at 6 h postpartum and remained elevated at 12 h postpartum; there were no changes in primiparous cows for these analytes. The total secretion of Ca in the colostrum from the first milking was similar in both groups and positively correlated with serum Ca at 6 and 12 h after calving. It is concluded that postpartum increases in the calcidiol and calcitriol concentration were a normal response to the decrease of serum calcium concentration only in multiparous cows. The total Ca secretion in the colostrum of the first milking postpartum does not reflect the grade of hypocalcemia.

Some Metabolic Effects of a Single Dose of Crystalline Dihydrotachysterol

1972 ◽  
Vol 50 (11) ◽  
pp. 1086-1090
Author(s):  
R. J. Burriss Garrett ◽  
Harmon C. Bickley ◽  
J. W. Little
Keyword(s):  
Single Dose ◽  
Food Intake ◽  
Serum Calcium ◽  
Serum Calcium Level ◽  
Calcium Concentration ◽  
Sudden Onset ◽  
Female Rats ◽  
Metabolic Effects ◽  
Serum Calcium Concentration ◽  
Quantitative Studies

A single 1 mg dose of crystalline dihydrotachysterol was administered by gavage to female rats. Quantitative studies of subsequent changes in serum calcium level, food intake, animal weight, and femur cortical fragility indicated that the effects of this drug were severe and protracted. Serum calcium concentration increased to a peak within 2 days and remained elevated throughout the experiment. Food intake and weight of dihydrotachysterol-treated animals declined severely and a sudden onset of femur cortical fragility was detected on the 5th day following treatment.

scholarly journals NEWCASTLE DISEASE ANTIBODY TITRE IS DEPENDENT ON SERUM CALCIUM CONCENTRATION

2000 ◽  
Vol 48 (1) ◽  
pp. 43-50 ◽  
Author(s):  
Jasminka Božičković ◽  
Gabrijela Krivec ◽  
W. L. Ragland ◽  
H. Mazija ◽  
P. Božičković ◽  
...  
Keyword(s):  
Serum Calcium ◽  
Newcastle Disease ◽  
Calcium Concentration ◽  
Dietary Calcium ◽  
Serum Calcium Concentration ◽  
Calcium Diet ◽  
Low Calcium Diet ◽  
High Calcium ◽  
Antibody Titres ◽  
Disease Antibody

Chickens were fed diets having optimal, high, and low levels of calcium for 42 days. Serum samples were collected at 14, 28 and 42 days of age, and serum calcium and haemagglutination inhibition titres for Newcastle disease virus were measured. The chickens were vaccinated at 14 days for Newcastle disease. Antibody titres were significantly increased by high dietary calcium and depressed by low dietary calcium. Mean titre was 2.5 (log2) for the optimal diet, 3.2 for the high-calcium diet, and 1.6 for the low-calcium diet. Antibody titres were dependent on serum calcium concentration (r2= 0.98 at 14 days, 0.99 at 28 days, and 0.78 at 42 days).

1,25-Dihydroxyvitamin D3 restores fertility of vitamin D-deficient female rats

1989 ◽  
Vol 256 (4) ◽  
pp. E483-E487 ◽  
Author(s):  
G. G. Kwiecinksi ◽  
G. I. Petrie ◽  
H. F. DeLuca
Keyword(s):  
Vitamin D ◽  
Vitamin D Deficiency ◽  
Serum Calcium ◽  
Reproductive Performance ◽  
Calcium Concentration ◽  
Female Rats ◽  
Reproductive Capacity ◽  
Dihydroxyvitamin D3 ◽  
Serum Calcium Concentration ◽  
1,25 Dihydroxyvitamin D3

Vitamin D deficiency reduces mating success and fertility in female rats, but it is not known if the reduction in reproductive performance is a direct action of vitamin D or the hypocalcemia associated with vitamin D deficiency. The effect of vitamin D deficiency with normocalcemia on fertility and reproductive capacity in female rats was investigated. Female weanling rats were maintained on vitamin D-deficient or vitamin D-replete diets until maturity and mated to age-matched, normal, vitamin D-replete males. Three groups of vitamin D-deficient females were maintained on diets varying in calcium and Pi concentrations to test the effect of vitamin D deficiency with different serum calcium and Pi concentrations on reproductive performance. Vitamin D-deficient females were capable of reproduction, but successful matings by all groups of vitamin D-deficient females were markedly reduced regardless of serum calcium concentration, when compared with matings with vitamin D-replete females. Fertility was also drastically reduced in litters from all groups of vitamin D-deficient females regardless of serum calcium concentration, when compared with litters from vitamin D-replete females. Vitamin D-deficient female rats that received vitamin D or 1,25-dihydroxyvitamin D3 were capable of successfully mating and giving rise to normal, healthy litters. These results indicate that vitamin D and not hypocalcemia is directly responsible for reduced reproductive capacity and fertility in vitamin D-deficient female rats.

Effect of vitamin D and dietary calcium on parathyroid activity

1965 ◽  
Vol 209 (3) ◽  
pp. 637-642 ◽  
Author(s):  
William Y. W. Au ◽  
Lawrence G. Raisz
Keyword(s):  
Vitamin D ◽  
Serum Calcium ◽  
Calcium Intake ◽  
Calcium Concentration ◽  
Acid Uptake ◽  
Serum Calcium Concentration ◽  
Calcium Diet ◽  
High Calcium ◽  
Normal Calcium

The effects of variations in vitamin D and calcium intake on parathyroid weight and amino acid uptake were studied in vivo. D-deficient rats on low or normal calcium intake developed hypocalcemia, parathyroid enlargement, and increased parathyroid uptake of α-aminoisobutyric acid (AIB). D-deficient rats fed a high-calcium diet and D-treated rats fed a normal-calcium diet had normal serum calcium concentrations, smaller parathyroids, and lower parathyroid uptake of AIB. When serum calcium concentration of vitamin D-deficient rats was increased acutely by vitamin D treatment, dietary lactose, or injection of calcium, parathyroid uptake of AIB decreased. Low-calcium medium stimulated and high-calcium medium suppressed AIB uptake of parathyroids from vitamin D-deficient rats in vitro. Parathyroids from vitamin D-deficient rats secreted bone-resorbing material in tissue cultures. The data indicate that both size and functional activity of rat parathyroids are inversely related to serum calcium concentration, and do not depend on the presence or absence of vitamin D.

Vitamin D Metabolism in Patients Intoxicated with Ergocalciferol

1985 ◽  
Vol 68 (2) ◽  
pp. 135-141 ◽  
Author(s):  
E. Barbara Mawer ◽  
J. T. Hann ◽  
Jacqueline L. Berry ◽  
M. Davies
Keyword(s):  
Vitamin D ◽  
Serum Calcium ◽  
Calcium Concentration ◽  
Mass Action ◽  
Vitamin D Metabolites ◽  
Serum Concentrations ◽  
High Concentration ◽  
Vitamin D Metabolism ◽  
Serum Calcium Concentration ◽  
Per Se

1. Vitamin D metabolites were measured on admission in eight patients intoxicated with ergocalciferol (serum calcium 3.01-4.05 mmol/l) and also during the subsequent 2 months in six of the eight. 2. Serum concentrations of 25-hydroxyergocalciferol, on admission, were grossly elevated in all patients (range 583-1843 nmol/l). 3. Serum calcium concentration was related significantly only to the concentration of 25-hydroxyergocalciferol (P = 0.003). 4. Concentrations of 25-hydroxyergocalciferol in serum were significantly related to those of calciferol (P = 0.004). 5. Elevated initial concentrations of 1,25-dihydroxycalciferol, mainly as 1,25-dihydroxyergocalciferol, were found in seven of the eight patients (range 179-313 pmol/l). 6. It is suggested that the hypercalcaemia in these patients may be explained by the action of 25-hydroxyergocalciferol at high concentration in competing for 1,25-dihydroxycalciferol receptors, thus exerting a biological effect per se, and also by increasing the synthesis of 1,25-dihydroxycalciferol through a mass-action effect on the renal 1α-hydroxylase.

The influence of vitamin D intake on serum calcium in tuberculosis

1981 ◽  
Vol 97 (1) ◽  
pp. 114-117 ◽  
Author(s):  
Grant Gwinup ◽  
Guy Randazzo ◽  
Alan Elias
Keyword(s):  
Vitamin D ◽  
Serum Calcium ◽  
Calcium Concentration ◽  
Dietary Vitamin ◽  
Controlled Study ◽  
Control Group ◽  
Serum Calcium Concentration ◽  
Significant Difference ◽  
Supplemental Vitamin ◽  
Prospective Controlled Study

Abstract. We report the first prospective controlled study designed to determine the effect of vitamin D ingestion on serum calcium concentration in patients with tuberculosis. Every patient admitted to the tuberculosis ward over a 6 month period, who was free of any condition which might influence serum calcium concentration, was randomly assigned to one of two groups. The diet of the first group was substituted with ergocalciferol 5000 units daily. The diet of the second group was not supplemented. In addition, the second group was randomly subdivided into two subgroups. The first subgroup received a diet unrestricted in vitamin D. The second subgroup received a diet containing less than 50 units of vitamin D. Serum calcium was determined at weekly intervals. In contradistinction to the results of a previously reported retrospective study, there was no significant difference between the group receiving supplemental vitamin D and the control group at any time during the entire period of study. Furthermore, there was no significant difference between the subgroup of patients receiving normal dietary vitamin D and the sungroup maintained on the diet restricted in vitamin D.

Serum Calcium and Vitamin D Status of Patients with Sickle Cell Disease in Curaçao

1997 ◽  
Vol 34 (2) ◽  
pp. 170-172 ◽  
Author(s):  
Fey P L van der Dijs ◽  
Fiona R M van der Klis ◽  
Fred D Muskiet ◽  
Frits A J Muskiet
Keyword(s):  
Vitamin D ◽  
Serum Calcium ◽  
Calcium Concentration ◽  
Vitamin D Status ◽  
Serum Concentrations ◽  
Cell Disease ◽  
Serum Calcium Concentration ◽  
Hydroxyvitamin D ◽  
Dihydroxyvitamin D ◽  
25 Hydroxyvitamin D

We measured parameters of calcium homeostasis and vitamin D status in HbSS patients (median age 8 years, range 3–19; 8 females, 10 males) and matched HbAA controls living in the tropical island of Curaçao. Serum calcium concentration in HbSS patients [2·32(0·07) mmol/L] was lower (ANCOVA, P = 0·002) than that of HbAA controls [2·44(0·14)]. None of the subjects had hypocalcaemia. There were no differences in serum concentrations of phosphate, total protein, albumin, intact parathyroid hormone (PTH), 25-hydroxyvitamin D [87(27) nmol/L in patients, 86(15) nmol/L in controls) and 1,25-dihydroxyvitamin D. There were no significant relations between PTH and 25(OH)D. We conclude that vitamin D status of HbSS patients in Curaçao is adequate.

Regulation of renal vitamin D hydroxylase activity in vitamin D deficient rats

1985 ◽  
Vol 63 (8) ◽  
pp. 978-982 ◽  
Author(s):  
M. Warner ◽  
A. Tenenhouse
Keyword(s):  
Vitamin D ◽  
Enzyme Activity ◽  
Single Dose ◽  
Calcium Concentration ◽  
Male Rats ◽  
Hydroxylase Activity ◽  
Deficient Diet ◽  
Serum Calcium Concentration ◽  
Pth Resistance ◽  
Detectable Serum

The regulation of renal mitochondrial 1-hydroxylase activity in chronic vitamin D deficiency was studied in male rats. These rats were born of mothers who had been raised from weaning (21 days) on a vitamin D deficient diet and who had no detectable serum 1,25-dihydroxycholecalciferol (1,25-(OH)2D) at the time their offspring were weaned (28 days). In the pups, renal mitochondrial 1-hydroxylase activity was undetectable before the 3rd week of life even though the animals were severely hypocalcemic from birth. The 1-hydroxylase activity first became detectable at 26 days of age, rapidly reached a maximum at day 34, then decreased to become undetectable again by 65 days. Throughout this time serum calcium concentration was <5.0 mg/dL and serum parathyroid hormone (PTH) concentration, measured by a midmolecule radioimmunoassay, was two-to five-fold greater than that found in vitamin D replete rats. 1-Hydroxylase activity could be restored in the +65-day-old animals by administration of a single dose of 2.5 μg vitamin D3. Enzyme activity was detected within 24 h, was maximal at 72 h, and returned to undetectable levels by 96 h after administration of the vitamin. Serum 1,25-(OH)2D which was undetectable before administration of the vitamin D3, was 108 and 458 pg/mL at 16 and 40 h, respectively, after the injection. The serum concentration of this metabolite then decreased progressively to 80 pg/mL by 6 days. 24-Hydroxylase activity first became detectable 48 h after vitamin D administration, increased to a maximum at 96 h, and thereafter decreased to become undetectable by 7 days. The urinary excretion of phosphate and cyclic AMP was 10% of control values between 65 and 90 days of age. These values became normal 4 days after a single dose of 2.5 μg vitamin D3. From these data it is concluded that there are two distinct levels of regulation of 1-hydroxylase activity: a vitamin D independent induction of the activity at the time of weaning that is transient and is not associated with any detectable 24-hydroxylase activity; and the second is a vitamin D dependent induction of enzyme activity seen in animals which prior to administration of the vitamin manifest the characteristics of PTH resistance and have no detectable renal hydroxylase activity. The mechanisms of these effects remain to be determined.

Calcium Excretion and Serum Calcium Concentration in Adult Intact and Gonadectomized Rats

Endocrinology ◽  
1968 ◽  
Vol 83 (6) ◽  
pp. 1375-1376 ◽  
Author(s):  
BERNARD F. RICE ◽  
ROY PONTHIER ◽  
M. CLINTON MILLER
Keyword(s):  
Serum Calcium ◽  
Calcium Concentration ◽  
Calcium Excretion ◽  
Serum Calcium Concentration
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