Significant Increase In Calcium Content Research Articles

Stimulatory effect of zinc acexamate administration on fracture healing of the femoral-diaphyseal tissues in rats

The effect of zinc acexamate on fracture healing of the femoral-diaphyseal tissues in rats was investigated in vivo. Zinc acexamate (0.3 and 10.0 mg Zn/100 g body weight per day) was orally administered to rats (4 weeks old) surgically fractured the femoral diaphysis for 14 to 28 days. Calcium content and alkaline phosphatase activity in the femoral-diaphyseal tissues were significantly decreased in rats with fracture healing, while bone acid phosphatase activity and protein content were markedly increased. The administration of zinc acexamate (10.0 mg Zn/100 g) for 28 days caused a significant increase in calcium content, alkaline and acid phosphatases activities, protein and deoxyribonucleic acid (DNA) contents in the femoral-diaphyseal tissues of rats with fracture healing. With the lower dose (3.0 mg Zn/100 g), zinc compound had a partial effect on bone components. Femoral mineral density in rats with fracture healing was significantly increased by the administration of zinc acexamate (10.0 mg Zn/100 g) for 28 days. Femoral-diaphyseal zinc content was significantly decreased in rats with fracture healing. This decrease was completely restored by the administration of zinc acexamate (10.0 mg Zn/100 g) for 28 days. The present study suggests that the supplement of zinc compound stimulates fracture healing of the femoral-diaphyseal tissues in rats.

Anabolic Effect of Soybean Saponin on Bone Components in the Femoral Tissues of Rats

The effect of soybean saponin on bone components in the femoral tissues of rats was investigated. Rats were orally administered saponin (100μg/ml/100g body weight) for 10 d. The administration caused a significant increase in calcium content, alkaline phosphatase activity, and deoxyribonucleic acid (DNA) content in the diaphyseal and metaphyseal tissues of the femur in the animals. When bone tissues were cultured for 24h in a medium containing either vehicle or saponin (10μg/ml of medium), the presence of saponin caused a significant rise in calcium content, alkaline phosphatase activity, and DNA content in the femoral-diaphyseal and metaphyseal tissues. The effect of saponin in increasing bone components was completely prevented by the presence of cycloheximide (10-6M), suggesting that the saponin effect is partly based on a newly synthesized protein component. This study demonstrates that soybean saponin has an anabolic effect on bone components in rats, suggesting its role as a nutritional factor in the prevention of osteoporosis.

Anabolic effect of genistein on bone metabolism in the femoral-metaphyseal tissues of elderly rats is inhibited by the anti-estrogen tamoxifen.

Whether the anabolic effect of genistein on bone metabolism in the femoral-metaphyseal tissues of elderly rats is inhibited by the anti-estrogen tamoxifen was investigated in vitro. Bone tissues were cultured for 24 h in the medium containing either vehicle or genistein. The presence of genistein (10(-6) and 10(-5) M) caused a significant increase in calcium content, alkaline phosphatase activity and DNA content in the bone tissues. The effect of genistein (10(-5) M) in increasing bone alkaline phosphatase activity and DNA content was equal to the stimulatory effect of 17 beta-estradiol (10(-10) and 10(-9) M) on the bone components. The genistein effect was not significantly enhanced by the presence of 17 beta-estradiol (10(-10) and 10(-9) M). The anti-estrogen tamoxifen (10(-7) M) completely blocked the effect of 17 beta-estrogen in increasing bone alkaline phosphatase activity and DNA content. The genistein (10(-5) M)-induced increases in bone alkaline phosphatase activity and DNA content were completely abolished by the presence of tamoxifen (10(-7) and 10(-6) M), although tamoxifen itself had no effect on the bone components. The present study demonstrated that the anabolic effect of genistein on bone components is inhibited by anti-estrogen tamoxifen. The effect of genistein may be mediated through estrogen-like action.

Treatment of Sorghum Grains with Calcium Hydroxide for Calcium Enrichment

Four varieties of sorghum grain (SB-1079, DSH-1, CSH-5, and SB-905) were subjected to four methods of treatment with saturated calcium hydroxide solution (soaking and drying with and without washing for germinated and ungerminated grains) for five different periods: dipping only, or 4, 8, 16, or 32 hours of soaking. Among all the varieties, treated germinated grain showed a higher calcium content than treated ungerminated grain. Irrespective of the method or duration of soaking, SB-905 showed a significantly lower calcium content than the other varieties. A maximum calcium content of 253.6 mg per 100 g of grain was obtained in the DSH-1 variety when germinated grain was soaked and dried, compared to a 55.0 mg per 100 g in the untreated sample. Washing after soaking resulted in a decreased calcium content in both germinated and ungerminated grains. Increasing the soaking time from simple dipping to four or eight hours resulted in a significant increase in calcium content. Further increases in soaking time to 16 or 32 hours caused a significant reduction in calcium content.

Stimulation of the renal endoplasmic reticulum calcium pump: A possible biomarker for platinate toxicity

Antitumor platinum compounds such as cisplatin are frequently nephrotoxic. The mechanism of nephrotoxicity has not been determined. It has been proposed that some toxicants may act by interfering with the mechanisms that control cellular Ca 2+ homeostasis. An important factor in the regulation of cytosolic Ca 2+ is the endoplasmic reticulum (ER) calcium pump. The activity of this pump was determined by measuring ATP-dependent microsomal sequestration of 45Ca. Administration of nephrotoxic doses of platinum compounds to rats was associated with an increase in renal ER calcium pump activity. This was the earliest response observed after cisplatin treatment (it occurred within 4 hr) and preceded increases in blood urea nitrogen and serum creatinine by at least 1 day. The dose-response curve for the increase in renal ER calcium pump activity was similar to the increase in the number and size of smooth ER aggregates observed in the S 3 segment of the proximal tubule 24 hr following cisplatin administration. Only minor morphological changes were observed at this time. There was a significant increase in calcium content of kidneys of rats 24 hr after treatment with a dose of cisplatin that caused a maximal increase in ER calcium pump activity. This indicates that a disruption of normal calcium homeostasis may occur before histological evidence of nephrotoxicity. Platinates that were not toxic to the kidney did not elevate renal ER calcium pump activity. It is suggested that the activity of the ER calcium pump may be a useful biomarker for cellular toxicity and may be a factor in the mechanism of toxicity.

Calcitonin increases succinate dehydrogenase activity dependently on calcium in the hepatic mitochondria of rats.

The regulatory effect of calcitonin (CT) on succinate dehydrogenase in the hepatic mitochondria of rats was investigated. Administration of CT (80 MRC mU/100 g body weight) produced a significant increase in calcium content and a corresponding elevation of succinate dehydrogenase activity in the hepatic mitochondria. These increases were dose-dependent. CT also increased succinate dehydrogenase activity and calcium content in the hepatic mitochondria of thyroparathyroidectomized rats. The CT-induced increase in enzyme activity was completely reversed by treatment with 1.0 mM ethylene glycol bis- (2-aminoethylether) N, N, N', N'-tetraacetic acid (EGTA). The increased activity was restored by addition of Ca2+ (2.5-25 μM). Trifluoperazine (25 and 50 μM), a calmodulin inhibitor, completely prevented the increase in succinate dehydrogenase activity caused by CT. Insulin (1.0 U/100 g) also increased succinate dehydrogenase activity in the hepatic mitochondria by about 30% (p<0.01), while the enzyme activity was not elevated by thyroxine (10 μg/100 g). The effect of insulin on the enzyme activation was attributed to the elevation of mitochondrial calcium. The present result indicates that succinate dehydrogenase activity is regulated by CT, and that the effect may be mediated through an increase of calcium in the mitochondria.

Hypocalcemic effect of zinc and mechanism in rats.

The effect of zinc on serum calcium was investigated after a single oral administration of zinc sulfate in rats. Zinc (5, 10, and 20 mg Zn/100 g body weight) administration produced a significant decrease of serum calcium. This effect of zinc was not inhibited by thyroparathyroidectomy. Zinc administration resulted in a significant increase in calcium content of lungs and muscle but it was not significant in liver, kidneys, spleen and heart. Intestinal calcium absorption and bile calcium excretion was not affected by zinc administration. However, the urinary calcium excretion after zinc administration decreased markedly. On the other hand, zinc administration caused a remarkable elevation of calcium content in gastric secretion. This effect was dose-dependent (5 and 10 mg Zn/100 g). However, an increase in gastric calcium after zinc administration was completely prevented by atropine (0.1 micrograms/100 g) treatment, which also showed a marked inhibition of hypocalcemic effect of zinc. Meanwhile, acetylcholine (4.0 micrograms/100 g) administration caused a significant decrease of serum calcium by zinc administration is mainly based on an increase in gastric calcium secretion.

The effect of apples and cranberries on calcium retention

1. The inclusion of 20 per cent fresh cranberries in an adequate diet for white rats, increased body calcium retention 8.4 ± .8 per cent. 2. Under similar experimental conditions, apples increased body calcium retention 10.8 ± 1.1 per cent. 3. Cranberries probably increased the calcium content of the femur ash slightly 1.8 ± .4 per cent, but apples showed no significant increase in calcium content.