• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.3
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• pp.480-487
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• 1997

The present study was designed to examine how Ca intake contributes to the increase of peak bone mass with growing female rats. Weaned rats were fed experimental diets consisting in five levels of Ca; very low(0.1%), low(0.2%), moderate(0.5%), high(1.0%) and very high(1.5%) for 4, 8 and 12 weeks. Bone growth, metabolism and Ca metabolism were determined. As for the rats fed for 4 weeks, the bone weight, length and breaking force and bone metabolism were not significantly affected by dietary Ca levels, whereas the current intakes of Ca were observed to have significantly affected the rats fed for 8 or 12 weeks with regard to the bone weight, length and breaking force and bone metabolism. The bone ash and Ca contents of the rats were affected by dietary Ca levels for the total period of feeding. It is suggested that dietary Ca itself affected the mineralization process either during the growth or later, although the resulting bone mass is not a linear function of dietary Ca content.

• Journal of Nutrition and Health
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• v.33 no.2
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• pp.147-157
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• 2000

This study examined the effects of excess intake of calcium (Ca) and iron (Fe) supplement on bone loss, nephrocalcinosis and renal function in osteoporotic model rats. Seven-week-old female rats were first fed a Ca-deficient diet for four weeks after ovariectomy operation, and then one of nine experimental diets for additional eight weeks, containing three levels of Ca, normal (0.5%) or high (1.5%) or excess (2.5%) and three levels of Fe, normal (35ppm) or high (210ppm) or excess (350ppm). The osteoporotic model rats showed a remarkable increase in body weight, serum alkaline phosphatase (ALP) and decrease in breaking force, Ca, P, Mg contents of femur. Serum Ca concentration was not significantly affected by dietary Ca and Fe levles. Liver Ca content increased in rats fed a high-and excess-Ca diet. Kidney Ca content and microscopic Ca deposition remarkably increased in osteoporotic model rats compared to control group, and showed a tendency to decrease in rats fed a excess-Ca diet. Breaking force of femur increased with increasing dietary Ca levels, but Ca, P contents of femur and serum ALP were not significantly affected by dietary Ca and Fe levels. Serum total protein decreased in rats fed a excess-Ca diet, BUN increased in rats fed a excess-Ca diet, while serum uric acid and creatinine were not significantly affected by dietary Ca levels. Urinary creatinine, GFR increased in rats fed a high-and excess-Ca, diet, and GFR was highest in rats fed a excess-Ca/excess-Fe diet. These results suggest that excess intake of Ca may increase breaking force of femur, but not increase mineral contents of femur, and decrease kidney function. Furthermore, excess intake of Fe and Ca concurrently may aggravate kidney function leading to potential health problems in ovariectomized osteoporotic model rats.

• Journal of Nutrition and Health
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• v.34 no.5
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• pp.541-546
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• 2001

This study examined the effect of various types of exercise on bone formation and resorption in rat. Five-week-old male Sprague-Daweley rats were randomly assigned to one of four groups with 10 animals in each; Control, Treadmill, Swimming, Resistance. The exercise regimen consisted of treadmill running at 25m/min, 1 hr per day, 5 days a week, and swimming for 1 hr per day, 5 days a week. Resistant exercise type with weight-bearing was designed to extend lower and upper extremities in order to feed the diet and water. Food intake showed no significant difference among groups but body weight gain and food efficiency were significantly increased in Control group as compared with exercise groups. Femur and tibia length and weight were higher in Control group and the density of therm tended to be higher in exercise groups than Control group, but this difference was not statistically significant. The breaking force of femur was the highest in Swimming group and tibia was the highest in Resistance group among groups, while there was no signigicant difference among the exercise groups. The calcium content of femur was significantly increased in Resistance group than the other groups. Calcium intake and urinary calcium showed no significant difference among groups, while calcium absorption and retention were significantly higher in exercise group than Control group. In conclusion, exercise training enhanced bone formation due to the positive effect on metabolism of calcium and bone which were different according to the types of exercise. (Korean J Nutrition 34(5) : 541∼546, 2001)

• Journal of Nutrition and Health
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• v.44 no.2
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• pp.101-111
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• 2011

It is controversial whether low calcium intake, commonly associated with osteoporosis, results in calcium accumulation in soft tissues. This study was conducted to investigate the effects of low calcium (Ca) and oxalate (ox) intake on soft-tissue Ca deposits and bone metabolism in ovariectomized (ovx) rats. Eight week old female Sprague-Dawley rats were ovariectomized and divided into four groups. The rats were fed experimental diets containing low (0.1%, w/w) or normal (0.5%, w/w) Ca with or without sodium oxalate (1%, w/w); Sham/NCa, Ovx/NCa, Ovx/LCa, Ovx/NCa-ox, Ovx/LCa-ox for 6 weeks. All ovx rats showed a remarkable increase in body and tissue weight, glutamic oxaloacetic transaminase, glutamic pyruvic transaminase, blood urea nitrogen, alkaline phosphatase, and decreases in weight, ash, and Ca contents, as well as bone breaking force compared to those in sham rats. Serum Ca concentration was not significantly affected by dietary Ca levels or ox intake. Kidney Ca, ox acid content, and microscopic Ca deposition increased remarkably in the Ovx/LCa-ox group compared to those in the other groups. Ca content in the spleen and aorta also increased significantly, but the weight contents, Ca, bone breaking force, and Ca and oxalic acid in feces decreased significantly in the Ovx/LCa-ox group. Serum parathyroid hormone levels were not significantly different among the groups. These results indicate that low Ca intake decreased bone mineral content and increased Ca deposits in soft tissues, which was aggravated by ox intake in ovx rats. Thus, high ox intake may result in a kidney disorder in patients with osteoporosis who eat a low Ca diet.

• Korean Journal of Exercise Nutrition
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• v.25 no.2
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• pp.33-37
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• 2021

[Purpose] Sex hormones deficiency leads to dramatically bone loss in particular postmenopausal women. Royal jelly has anti-osteoporosis effect due to maintain bone volume in that condition. We hypothesized that royal jelly protein (RJP, a latent residue after extracting royal jelly) also prevents bone deficient in ovariectomized (OVX) female rats, the animal model of postmenopausal women. [Methods] Female Sprague-Dawley rats (n = 30, 6 weeks age old) were sham operated (Sham; sham operated group, n = 7), OVX control group (OC, n = 7), OVX with low RJP intake group (ORL, n = 8), and OVX with high RJP intake group (ORH, n = 8) during 8 weeks experimental periods. In the end point of this experiment, the bone samples (lumbar spine, tibia, and femur) were surgically removed under anesthesia. These bone samples were evaluated bone mineral density (BMD) and bone strength. [Results] BMD of lumbar spine in RJP intake groups (ORL, ORH) were higher than that in OC group (p < 0.05 and p < 0.01) in RJP intake volume dependent manner. BMD of tibial proximal metaphysis and diaphysis in RJP intake groups were also higher than these in OC group (p < 0.01 and p < 0.01 / p < 0.05 and p < 0.001). In addition, breaking force of femur in RJP intake groups were significantly increase compared with that in OC group (p < 0.001 respectively). [Conclusion] These findings indicate that RJP contribute to prevent sex hormone related bone abnormality.

• Journal of Nutrition and Health
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• v.39 no.2
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• pp.109-114
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• 2006

The effects of the erect bipedal stance exercise on bone mass and the biomarkers of bone formation and resorption were investigated in rats. Five-week old rats were assigned into control and exercise groups. The rats of exercise group were weight-bearing-trained for 13 weeks in the cage designed to adjust progressively the height from 26.5 cm to 31.5 cm to force the rats rising an erect bipedal stance for feeding and drinking. There was no significant difference in food intakes between two groups. But body weight gain was significantly increased in control group. The lengths of femur, tibia, humerus and radius were significantly longer in control group than exercise group, but the femur and tibia weights per body weight were significantly higher in exercise group than control group. Also the breaking force of femur and tibia in exercise group were higher than control group significantly. The calcium contents of femur and tibia were significantly increased in exercise group than control group. The activity of bone specific alkaline phosphatase (B-ALP) and the osteocalcin contents of serum (the biomarkers of bone formation) in exercise group were higher than control group, but the carboxyterminal propeptide of type I procollagen (P1CP) contents of serum did not show any difference between two groups. However the urinary deoxypridinolin (DPD) excretion, biomarker of bone resorption, was significantly lower in exercise group than control group. From these results, it has been indicated that the erect bipedal stance exercise enhanced the density and the strength of femur and tibia by increasing biomarkers of bone formation and suppressing a biomarker of bone resorption in rats.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.6
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• pp.601-607
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• 2002

The present study was designed to examine how sea tangle intake contributes to the content of bone calcium and breaking force of femur with growing female rats. Weaned rats were fed on experimental diets consisting in four levels of sea tangle powder; $0\%$ (control), $0.5\%$, $1.0\%$ and $1.5\%$ for 4 and 8 weeks. Body weight gain and feed intake were not significantly affected by added amount of sea tangle. Bone breaking strength, ash content and calcium levels of the femur of rats fed on diets with sea tangle were higher than those of control groups (p<0.05). But moisture content weight and length of femur did not show any significant difference among groups. TP, ALB, TC, TG, AIP, osteocalcin, GOT and GPT levels in serum did not show any significant difference through the total feeding period but calcium and phosphorus contents of serum increased with increase in feeding period, significantly in $0.05\%$ level by added amounts of sea tangle. Calcium levels in feces increased significantly (P<0.05), but ash levels were not changed significantly by added amount of sea tangle. We could expect from this results that the ingestion of sea tangle (Kjellemaniella crassifolia) could be helpfull to increase bone calcium content and calcium absorption as well as to intensify the femur stength and to increase the calcium content of rats.

• 한국노년학
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• v.31 no.2
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• pp.303-315
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• 2011

The purpose of this study was to investigate effect of resistance training on BMD and bone metabolism related markers in aging rats. Thirty male Spraugue-Daweley rats were divided into sedentary (CON; n=10 ) non-load resistance trained(NLRTG; n=10), and load resistance trained(LRTG; n=10) groups at the age of 64 weeks. The rats in the resistance training groups((NLRTG and LRTG) performed the tower climbing exercise 4 times a week. The LRTG groups were conditioned to climb a vertical ladder with weights appended to their tail 4 days/wk for 12 wks. After 12 weeks of exercise, serum osteocalcin, bone mineral density (BMD), breaking force, ash, Ca, and P in the femur were measured. After training, serum osteocalcin (OC) was significantly (p < 0.05) higher in both LRTG and NLRTG when compared to Control. Right femur BMD was significantly (p < 0.05) greater for LRTG when compared to both NLRTG and Control with no significant difference between NLRTG and Conrtol. The breaking force of femur was significantly (p < 0.05) greater for LRTG and NLRTG when compared to Control. The Ash, Ca, content of femur were significantly increased in resistance training groups than control group. These results suggest that the increase in bone mineral density induced by resistance training is mediated by changes in bone microarchitecture as well as training intensity and osteocalcin.

• Journal of Nutrition and Health
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• v.28 no.5
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• pp.434-441
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• 1995

The model rats with postmenopausal osteoporosis were comparatively observed with regard to the effects of bovine ash and calcium phosphate on calcium metabolism. The modelling design involved the five week-old week-old female SD-strain rats ovariectomized and fed a low-Ca diet(20% casein, 0.06% Ca and 0.38% P) for three weeks. The rats were divided into five groups, one of which was fed the low-Ca diet(basal), and the rest of which were divided into five groups, one of which was fed the low-Ca diet(basal), and the rest of which were fed four kinds of Ca-supplemental diets(20% protein, 1.06% Ca and 0.8% P) for three weeks. The Ca-suplements diets contained two kinds of Ca sources, bovine bone ash(BBA) or calcium phosphate, tribasic [Ca3(PO4)2] and two kinds of protein sources, casein or isolated soy protein(ISP). The model rats of postmenopausal osteoporosis fed basal diet showed a significant decrease in Ca utilization in reference to serum Ca concentration, breaking force of bone, Ca and P contents of bone, and Ca absorption and retention. However, the supply of Ca for three weeks demonstrated the improved utilization of Ca. One step further, BBA was more effective than calcium phosphate in improving Ca utilization in ISP-fed groups. On the other hand, no significant difference was seen in casein-fed groups. It is to conclude that BBA could be more effective in accelerating Ca utilization under vulnerable dietary or physiological conditions such as vegetable protein intake and osteoprosis.

• Journal of Nutrition and Health
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• v.34 no.5
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• pp.532-540
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• 2001

This study explored the effect of calcium levels and/or ovariectomy on bone composition and its related factors using the female Sprague-Dawley rats which achieved peak bone mass in normal(0.5%) calcium intake during growth period. The rats were randomly divided into six groups and fed 0.1%, 0.5% and 1.5% calcium diets for 8 weeks after ovariectomized and sham operation. The results indicated that body weight gain was higher in ovariectomized groups than sham groups, regardless of dietary calcium levels and food intakes. Serum Ca and P concentrations were normal level regardless of dietary calcium levels and operation. Estrogen concentration was decreased in ovariectomized rat groups. Serum alkaline phosphatase activity and urinary hydroxyproline were increased in ovariectomized groups. When rats were fed normal Ca diet during growing period, weight, length and breaking force of femur were not significantly different in all groups but increased the same level. Generally, lipid contents in lumbar and femur were lower in low calcium groups and this effect was more pronounced in femur. In case of femur, the significant decrease in Ca contents of bone was observed in a relatively short period of feeding low Ca diet, even though it appeared th desirable peak bone mass had achieved through the growing period by supplementing the adequate amount of calcium. The marked decrease of estrogen levels after ovariectomy did not seem to influence greatly bone parameters measured except bone wet weight. Therefore, this study indicated that lower intake of Ca might be more important determinating factor against osteoporosis than postmenopausal state stimulated by ovariectomy in female rats. With normal or high intake of Ca it appears possible to prevent bone loss in postmenopausal period, and this might apply only in case of achieving peak bone mass in the growing with the adequate intake of calcium. (Korean J Nutrition 34(5) : 532∼540, 2001)