Calcium-deficient Animals Research Articles

Osteoarthritic cartilage lesions in the bovine patellar groove: A macroscopic, histological and immunohistological analysis

A high percentage of osteoarthritis (OA)-like patellar groove lesions in the stifle joint in calcium-deficient bulls has been recently reported. The prevalence of these lesions in bulls deficient in or supplemented with calcium was compared to findings in culled and healthy bulls to determine whether they represent normal anatomical variations, developmental anomalies or OA. It was hypothesized that the patellar groove lesions may represent OA. Distal cartilage samples from 160 femurs were analysed using a macroscopic Société Française d’Arthroscopie (SFA) OA grading system. Samples representing different SFA grades were subjected to Osteoarthritis Research Society International (OARSI) histological and high-mobility group box 1 (HMGB1) immunohistological OA grading. For a qualitative analysis three OA samples were immunostained for interleukin (IL)-1β, matrix metalloproteinase (MMP)-13 and collagenase-produced COL2-3/4M neoepitopes.Patellar groove lesions were found in 48% of the femurs and were highest in calcium-deficient animals (71%, P<0.001). All three different grading systems disclosed OA in culled bulls, but no focal areas of cartilage necrosis. OARSI and HMGB1 grades were fairly concordant (Spearman’s ρ=0.95, P<0.001; Cohen’s κ=0.23, P<0.005), both with a slight disparity with the SFA grade (ρ=0.80 and 0.87, P<0.01; κ=0.36 and 0.46, P<0.001). IL-1β, MMP-13 and COL2-3/4M staining patterns were compatible with OA. The study showed that patellar groove lesions are common in bulls. In all SFA, OARSI and HMGB1 graded samples the lesions clearly demonstrated OA and showed OA-typical pathophysiology. Arthroscopic SFA grading showed similar changes in calcium-deficient and calcium-supplemented bulls, but in the absence of a time course study and histological data the primary nature of these lesions could not be established with certainty.

成長期ラットの虚弱下顎骨における食餌療法の影響に関する実験的研究 : 骨塩量とセファロ分析による形態計測

Bone mineral content increases with age in developing children and it has been reported that peak bone mass is obtained around 17-20 years of age. Therefore, the accumulation of adequate bone mass in this period is a key determinant in prevention of osteoporosis. Rats aged 5 weeks, corresponding to schoolchildren in human, were used in the present study. The effects of dietary therapy rich in calcium content on mandibular osteoporosis produced by calcium deficiency were investigated, using computed X-ray densitometry and cephalometry. The results were as follows. 1. Weight Calcium deficient animals exhibited significantly lower weight than control animals 4 weeks post-experimentally (p<0.05). The difference disappeared, however, after the animals were fed standard diet for 8 weeks. 2. Densitometry No significant differences were identified between the control and experimental groups in bone density of mandibular angle, condylar and coronoid processes. 3. Cephalometry A. Coordinate analysis The experimental groups exhibited significantly lower values than control group in mandibular angle, condylar and coronoid processes (p<0.05). However, no significant differences were found between the experimental and control groups in mandibular body and alveolar process. B. Distance measurement The experimental groups showed significantly shorter mandibular border, ramus, and coronoid process than the control animals (p<0.05). C. Area measurement The experimental groups showed significantly less area of mandibular angle and condylar process than the control animals (p<0.05). From the foregoing results, dietary therapy rich in calcium content showed a nagetive result for recovery of mandibular osteoporosis in school childhood with cephalometric investigation, but gave a positive result measured by computed X-ray densitometry.

Strontium alters the complexed acidic phospholipid content of mineralizing tissues

High dietary strontium induces rickets in both calcium-replete and calcium-deficient animals. To test the hypothesis that strontium directly perturbs complexed acidic phospholipid (CPLX) metabolism and thus, mineralization, the effect of strontium treatment on CPLX formation was studied in solution, in culture, and in growing rats. Synthetic CPLX containing calcium or strontium were found to be similar in composition. Strontium, however, appeared to incorporate into CPLX less avidly than calcium. Mineralizing chick limb bud mesenchymal cell cultures treated with strontium demonstrated a significantly increased CPLX content and decreased 45Ca uptake compared to calcium-treated cultures. Long bones from young growing rats fed a diet supplemented with strontium demonstrated defective mineralization based on radiologic and histologic analyses. Metaphyseal bone of strontium-fed rats contained significantly greater amounts of CPLX and had significantly lower ash weights compared with control bone. Thus, treatment of mineralizing tissues with strontium both in vitro and in vivo resulted in defective mineralization and an accumulation of CPLX. Strontium appears to perturb mineralization, in part, by a direct effect on the cells of mineralizing tissues.

Effect of calcium deficiency on the content of nonreducible crosslinks in rat mandibular bone

The effect of calcium deficiency on the content of the nonreducible cross-linking amino acid, pyridinoline, in rat mandibular bone was studied. An apparent decrease in serum and bone calcium levels was observed beginning at four weeks after initiation of a calcium-deficient diet. The pyridinoline content in the bone of calcium-deficient animals began to increase at four weeks and thereafter increased markedly as compared to that of controls. Collagen content increased significantly six weeks after calcium deficiency. These results suggest that calcium deficiency inhibits mineralization and promotes the formation of pyridinoline in rat mandibular bone.

Glucose-Stimulated Insulin Secretion in Rats with Normal Plasma Calcium Levels: Effects of Calcium Deficiency

Weanling Wistar rats were pair-fed for 9 days a control or a calciumdeficient diet. After a 12-hour fast the rats were injected intraperitoneally with glucose (250 mg/100 g body weight), and blood was collected 15, 30 and 60 minutes after the injection. Before injection, calcium (9.7 ± 0.2 mg/100 ml), glucose and insulin plasma levels were identical in the control and deficient animals, although calcium-deficient animals showed a small but significant increase in blood plasma magnesium levels. Blood glucose levels were higher in the calcium-deficient rats than in control rats 15 to 30 minutes after the glucose injection (15.4 ± 1.4 vs. 9.7 ± 0.4 mM, P < 0.01, 30 minutes after). Plasma insulin levels were significantly lower 15 minutes after the glucose injection (24 ± 4 vs. 73 ± 8 µU/ml; P < 0.01). Calcium deficiency is therefore associated with a decreased response to the glucose tolerance test in the absence of any change in the blood plasma calcium levels.calcium deficiency plasma calcium glucose insulin

The effects of zinc and calcium deficiencies on the rate of bone resorption in the rat

An effect of zinc deficiency on bone resorption was assessed in rats, by measuring the rate of resorption in rapidly growing animals and a pathologically increased resorption secondary to calcium deficiency. Bone resorption was quantitated by the loss of 3H-tetracycline from previously labeled bone. There was no effect of zinc deficiency on bone resorption in either normally growing or calcium deficient animals. Calcium deficiency alleviated the effect of zinc deficiency on body weight. In calcium deficient animals, bone zinc concentration was almost double that of calcium supplemented animals, suggesting a partial substitution of zinc for calcium in bone mineral.

Changes in red cell space of bone in hypocalcemic states: studies in rat femur.

With the use of technetium-99m-labeled red cells, the red cell space of the femur was found to be increased in rats fed a 0.01 percent Ca diet for 4 wk, at which time they were also hypocalcemic. Rats fed the same diet for 2 wk did not demonstrate hypocalcemia nor hypervascularity of the femur. Thyroparathyroidectomized (TPTX) rats fed the calcium-deficient diet produced hypocalcemia nor hypervascularity as did TPTX rats fed a normal diet for 4 wk. However, bone vascularity was normal at 2 wk post-TPTX (normal diet) when the degree of hypocalcemia was less marked. Inhibition of prostaglandin synthetase with oral indomethacin 0.2 mg/100 g per 12 h for 60 h did not alter the red cell space estimates but did increase bone blood flow in both normal and calcium-deficient animals. Acute restoration of normocalcemia with CaCl2 orally in the calcium-deficient rats did not revert the bone hypervascularity. The evidence suggests that in these models of hypocalcemic states, the rise in the vascular space of bone does not result from the influence of PTH, calcitonin, diet, or prostaglandins.

Vitamin D metabolism in adult rats at low and normal calcium intake and the effect of cadmium exposure.

1. Chromatography measurements indicated that adult rats converted 25-hydroxycholecalciferol into 1,25-dihydroxycholecalciferol at a lower rate than that reported earlier for young animals. In serum, less-polar metabolites were found which probably represented vitamin D esters and vitamin D3. 2. A low dietary intake of calcium resulted in an evident increase in the fraction corresponding to 1,25-dihydroxycholecalciferol in the kidneys and also in the intestinal mucosa and serum. 3. Inclusion of 0.67 mmol of cadmium/l of drinking water at a low dietary intake of calcium resulted in an increased accumulation of both cadmium and zinc in the kidneys and liver compared with values at a normal dietary calcium intake. 4. At a normal dietary calcium intake, cadmium exposure caused inhibited production of 1,25-dihydroxycholecalciferol by the kidneys and an increased accumulation of 24,25-dihydroxycholecalciferol, vitamin D3 and vitamin D esters in the serum. 5. The inhibitory effect of cadmium on the renal conversion of 25-hydroxycholecalciferol into 1,25-dihydroxycholecalciferol was almost completely counteracted by a simultaneous low dietary calcium intake. Cadmium-exposed, calcium-deficient animals also showed a maintained accumulation of 1,25-dihydroxycholecalciferol in the intestinal mucosa.

A nutritional basis for lead pica

Lead pica is a puzzling behavioral phenomenon involving the continued voluntary ingestion of a toxic substance. Calcium deficiency produced an elevated proportion of lead ingestion while magnesium and zinc deficiency produced proportional levels of lead ingestion intermediate to control and calcium deficient rats. Partrial restoration of calcium did not eliminate the increased proportion of lead ingestion while full calcium restoration did. Calcium deficient rats offered lead to drink gained more weight than deficient rats not offered lead. Control animals showed a reduction in their intake of novel solutions ingested following intubation of lead acetate while calcium deficient animals did not. Rats deficient in calcium, iron and zinc also showed elevated proportional levels of quinine sulfate ingestion compared to controls suggesting that a pica may be a general response to nutritional deficiency. The increased proportion of lead ingestion by calcium, zinc and magnesium deficient rats and the failure of calcium deficient rats to form a learned aversion to lead acetate, suggests that mineral deficiency may be a major factor in producing lead pica.

Metabolism of 109Cd in rats fed normal and low-calcium diets.

Growing male rats were fed purified diets that contained either 0.6% or 0.1% calcium to investigate the relationship of calcium intake to the uptake, tissue distribution, and excretion of 109Cd. An equal number of rats were fed either the 0.6 or 0.1% calcium diets for 4 wk before they were used for experiments. In the first experiment 11 rats from each dietary group were administered 5 muCi 109Cd by stomach tube and were then maintained in metabolism cages for 72 hr. Animals fed the low-calcium diet took up more 109Cd, as significantly higher levels of radioactivity were found in the intestinal mucosa, serum, lungs, liver, kidneys, and urine and a significantly lower level was found in the feces. Higher levels of 109Cd, associated with low-molecular-weight proteins that may be related to the absorption process, were found in the intestinal mucosa of the low-calcium group. In the second experiment 10 rats from each dietary group were administered 5 muCi 109Cd by subcutaneous injection and then maintained in a metabolism cage for 72 hr. No significant differences were found in the distribution or excretion of 109Cd except for the lungs where radioactivity was greater in the low-calcium group. The results of the study indicate that the enhanced cadmium toxicity observed in calcium-deficient animals exposed to the heavy metal is the result of an increased uptake from the small intestine.

Bone repletion in calcium deficient rats fed a high calcium diet.

The changes in the tibial diaphysis as a result of feeding a high calcium diet to rats previously fed a calcium free diet were determined. The calcium free diet resulted in an increase in the medullary area, and the subsequent feeding of a high calcium diet caused a reduction in medullary area. However, the amount of endosteal bone lost during ten days of feeding a calcium free diet was not completely restored after 78 days of feeding a high calcium diet. The decrease in medullary area was brought about by decreased endosteal bone resorption and particularly by increased endosteal bone formation. Bone formation at the periosteum and at the epiphyses were unchanged, indicating that the high calcium diet did not cause a generalized increase in bone formation. The increase in endosteal bone formation was limited to those sites along endosteum where greatest loss of bone had occurred during the calcium depletion period. This indicates that a local factor is at least partially responsible for the stimulation of endosteal bone formation during calcium repletion. Mechanical stress, which stimulates bone formation, was increased in calcium deficient animals and returned to normal during calcium repletion. In addition, mechanical stress was probably greatest in those sites where the greatest amount of bone repletion occurred and may have been the factor which contributed to the increase in endosteal bone formation during calcium repletion.

Calcium release from the skeletons of rachitic puppies.

The experiment was carried out on 3-month old puppies. Control animals received a diet normal in calcium and vitamin D. The diet for one group of experimental animals was deficient in both calcium and vitamin D, while another experimental group was fed a diet deficient in calcium but with adequate vitamin D. The response of these animals to injected parathyroid extract was evaluated over a 4 month period. The serum calcium response fell after approximately 20 days in both the calcium-deficient (vitamin D-replete) and the calcium- and vitamin D-deficient animals. The effect on the parathyroid response of the addition of calcium or vitamin D in vitamin D- and calcium-deficient animals was also evaluated. The addition of vitamin D to rachitic animals did not restore the response to parathyroid extract; however, in calcium- and vitamin D-deficient animals with normal calcium levels there was a restored response to parathyroid extract. Morphologic studies were made of the bone at various times during the experimental period; the presence of osteoid tissue correlated with the absence of a response to injected parathyroid extract. The results suggest that parathyroid hormone acts independently and requires the presence of mineralized bone for its action in raising the serum calcium. Vitamin D appears to be important in the mineralization of new bone tissue.

Effect of a low calcium diet on bone crystallinity and skeletal uptake of Ca45 in rats.

SummaryChemical and X-ray diffraction analyses were performed on femurs of rats receiving a low (0.1%) and high (0.8%) calcium diet with (50 ppm) and without (0 ppm) fluoride supplementaton in the water. In addition, uptake of Ca45 by the ends and shafts of tibia was determined. Bone crystal-linity (i.e., crystal size and/or perfection) was not affected by calcium intake, and the improvement in crystal texture produced by fluoride was the same for the high and low calcium groups. Skeletal uptake of radiocalcium was approximately 20 times higher in calcium deficient animals. Fluoride decreased slightly the uptake of radiocalcium.

The influence of a low and high calcium diet on the development and chemical composition of the skeleton in swine

(1) The skeletons of young pigs on a ration composed mainly of cereal grains but with the addition of cod-liver oil show a very distinct lack of calcification, the percentage of ash being about 12 per cent. lower than in the bones of normal animals.(2) Calcification of the bones proceeds up to maturity. A difference of about 360 gm. tricalcic phosphate was found between the same mature bones of normal and calcium-deficient animals.(3) The ratio of lime to phosphate is almost the same in the different bones of the same individual as well as in the normal and rachitic bones of swine. The main characteristic of the bones in low-calcium rickets is a low-ash content, but the composition of the ash is normal.