• Journal of Nutrition and Health
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• 제30권3호
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• pp.266-276
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• 1997

To investigate the effects of dietary protein and calcium levels on calcium and bone metabolism Sprague-Dawley male growing rats weighting approximately 91.4g were divided into four groups and fed one of the following four experimental diets-15% protein 0.2% calcium ; 15% protein 0.5% calcium ; 30% protein 0.2% calcium ; 30% protein 0.5% calcium-for five weeks. Calcium intake and excretion, apparent calcium absorption were measured and bone densities and mineral contents of femur and scapula were analyzed. Calcium excretion through feces and urine was significantly greater in animals receiving diets of higher calcium. Fecal calcium but not urinary calcium excretion was greater when the protein level was increased from 15% to 30%. Apparent calcium absorption rate was significantly higher with lower calcium intakes. Serum alkaline phosphatase activity was significantly higher in 0.2% calcium group than in 0.5% calcium group, while urinary hydroxyproline excretion was essentially same among all experimental groups. Weights and mineral contents or protein. Bone weights were greater, but calcium and ash contents of femur and scapula were lower in animals on the diet containing low calcium and high protein, which suggests that bone metabolism may be affected by the interaction between calcium and protein intake. These results indicate that during growth high protein intake might be beneficial to bone health if the diet is sufficient in calcium, however, if the diet fails to provide an optimum amount of calcium, such practice might be detrimental.

• Journal of Nutrition and Health
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• 제21권2호
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• pp.99-112
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• 1988

This study was performed to investigate the effects of dietary protein and calcium levels on calcium metabolism in eight healthy Korean adult females. The 2-day metabolic study consisted of a 2 day adaptation period and three 6-day experimental periods. Three experimental diets were low protein low calcium(LPLCa : protein 44g, Ca 422mg), higher protein low calcium(HPLCa : protein 85g, Ca 365mg), and high protein high calcium (HPHCa : protein 84g, Ca 727mg). The apparent calcium absorption was likely to be affected by the calcium intake rather than by the protein intake. Average calcium absorption rate was about 23-29% of calcium intake. The calcium balance was -21.44mg for LPCa, -25.02mg for HPLCa, and -3.22mg for HPHCa. Avergae urinary calcium excretion was 127.7mg for LPLCa, 108.6mg for HPLCa, and 215.4mg for HPHCa. Urinary calcium excretion was more closely related to the changes of calcium intake rather than of protein intake. These results seemed to be due to the interactions between the high phosphours contained in the high protein diet and the little discrepancy of protein intake levels.

• Journal of Nutrition and Health
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• 제28권2호
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• pp.144-151
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• 1995

This study investigates the supplementing effects of milks by various heat treatment on growth performance and protein and calcium metabolism of rats. For 4 weeks, raw, LTLT-HTST-and UHT-processed milks were given to rats which fed on a calcium free, semi-synthetic diet containing 5%casein. There were no significant differences among the experimental groups in weight gain, feed efficiency ratio and the serum level of total protein and calcium. Also, no significant differences were showed in protein efficiency, nitrogen balance, apparent protein digestibiltiy and the contents of weight and calcium of the left femur as well as 2 incisors. However, the biological value of protein in the UHT-milk group was significantly higher than that of the raw-milk group. The apparent calcium digestibility and calcium balance in the UHT-milk group were higher than those in the raw-, LTLT- and HTST-milk groups. The weight of left femur in all the groups supplemented with various heat-treated milks was significantly impair the nutritive value of protein and calcium in milk. Futhermore, UHT-processing may improve the bioavailability of protein and calcium in milk.

• Journal of Nutrition and Health
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• 제27권1호
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• pp.3-11
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• 1994

This study was carried out to examine how dietary protein and calcium levels in rats fed fat-enriched diet affect the total lipid and cholesterol contents of blood and tissues. Male Sprauge-Dawley rats weighing approximately 200g were fed six purified diets which contained 18%(w/w) beef tallow, 1% (w/w) cholesterol, two source of protein, casein or isolated soy protein (ISP) and three levels of dietary calcium, 0.1%, 0.4% and 1.0%, first, for four weeks, and second, for eight weeks. The contents of the total lipid, cholesterol and triglyceride in blood, liver, heart and feces were determined. After four weeks feeding serum lipid and cholesterol concentrations significantly decreased in rats fed 1.0% (w/w) level calcium, regardless of dietrary protein sources. After eight weeks, these concentrations were significantly lower in the rats fed soy protein than in casein-fed rats. As dietary calcium level increased serum and tissue lipid and cholesterol contents were decreased and fecal lipid excretion increased. It is concluded that hypolipidemic and/or hypocholesterolemic effects of soy protein and calcium were partly due to decrease in lipid absorption.

• Preventive Nutrition and Food Science
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• 제15권4호
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• pp.282-286
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• 2010

To isolate a calcium-binding peptide from chlorella protein hydrolysates, chlorella protein was extracted and hydrolyzed using Flavourzyme, a commercial protease. The degree of hydrolysis and calcium-binding capacity were determined using trinitrobenzenesulfonic acid and orthophenanthroline methods, respectively. The enzymatic hydrolysis of chlorella protein for 6 hr was sufficient for the preparation of chlorella protein hydrolysates. The hydrolysates of chlorella protein were then ultra-filtered under 5 kDa as molecular weight. The membrane-filtered solution was fractionated using ion exchange, reverse phase, normal phase chromatography, and fast protein liquid chromatography to identify a calcium-binding peptide. The purified calcium-binding peptide had a calcium binding activity of 0.166 mM and was determined to be 700.48 Da as molecular weight, and partially identified as a peptide containing Asn-Ser-Gly-Cys based on liquid chromatography/electrospray ionization tandem mass spectrum.

• Journal of Nutrition and Health
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• 제25권5호
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• pp.360-378
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• 1992

This study was performed to investigate effect of dietary protein and calcium levels on cad-mium intoxication in rats. Adult Sprague-Dawley male rate(245$\pm$21g) were blocked into 18 groups of 7 animals according to body weight Nine experimental diets different with protein(40%, 15%, 7%) and calcium (1.3%, 0.6%, 0.1%) levels were prepared. Nine groups of animals were fed each diet with 50ppm cadmium in drinking water and the other 9 groups without cadmium for 30days. Results were summarized as follows: 1) Body weight gain F. E. R(Food Efficiency Ratio) and weights of liver kidney and femur were higher in high protein groups among cadmium exposed groups. 2) Cadmium contents in liver and intestine were higher in rats fed high protein diet or low calcium diet among cadmium exposed groups. Fecal cadmium excretion was highest in high protein-high calcium diet group among cadmium exposed animals. Metallothionein contents in liver kidney and intestine were higher in animals exposed to cadmium and fed high protein diets. 3) Gel filtration chromatography of cytosolic solution showed that the higher dietary protein and calcium levels were the more cadmium was found in metallothionein fractions. 4) No gross histopathological change was seen in liver kidney and intestine of cadmium exposed rats. However a significant increase of smooth endoplasmic reticulum which was alleveated by high protein-high calcium diet was observed. Results obtained indicated that not only high protein diet but also high calcium diet showed preventive effect on cadmium intoxication by increasing the induction of metallothionein syn-thesis and decreasing the cadmium absorption.

• 한국지역사회생활과학회지
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• 제13권2호
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• pp.53-61
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• 2002

This study is to find out how the 4 types of calcium salt such as calcium carbonate, calcium phosphate, calcium lactate and calcium citrate in soy protein diet, the vegetable protein source, affect the calcium utilization in the body. To do so, calcium, phosphate and creatinine concentration and ALP activity in blood as well as the content of calcium and ash, the length, weight strength, and the calcium utilization in the bone were measured. Four groups of Sprague-Dawley male rats with the weight of around 180g were fed for 3 weeks with the experimental diet. Each group was fed with the isolated soy protein containing 14% of the diet and the above mentioned 4 types of calcium salt as the calcium source. The results are as follows; 1. There were no differences of the feed intake, weight gain, and feed efficiency among groups. 2. ALP activity in blood was sinificantly high in calcium lactate group(P<0.05), but there were no differences of concentration of calcium, phosphates, and creatinine in blood among groups. 3. The weight, calcium content, calcium ratio in ash and the strength of bone were low when calcium lactate was provided(P<0.05). 4. The content of calcium in the liver was high in calcium lactate group and calcium citrate group(P<.0.05). 5. The exceretion of feces was low in calcium lactate group(P<0.05) and the excretion of urine was also relatively low. In addition, the ratio of absorption and the retention of calcium were high(P<0.05). In summary, out of four types of calcium salt such as calcium carbontate, calcium phosphate, calcium lactate and calcium citrate when calcium lactate was provided the ALP activity in blood was high and the weight, calcium content, calcium ratio in ash and the strength of bone were low. In calcium utilization, the ratio of absorption and retention of calcium were high, however it has lower effect than 3 other calcium types in improving weight, the content of calcium and the strength of bone.

• 한국식품영양과학회지
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• 제34권2호
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• pp.176-180
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• 2005

흰쥐를 대상으로 하여 식이 단백질 수준에 따라 칼슘 수준을 달리하여 식이를 공급하여 칼슘 식이효율, 칼슘대사와 관련된 호르몬, 대퇴골의 무게 및 칼슘 함유량, 골밀도를 측정하였다. 실험 식이의 구성은 \circled1 HPNC군-고단백 적정칼슘군(Protein: 400 g/kg diet, calcuim: 0.5%) \circled2 HPLC군-고단백 저칼슘군(Protein: 400 g/kg diet, calcium: 0.1%) \circled3 NPNC군-적정 단백 적정 칼슘군 protein: 200 g/kg diet, calcium: 0.5%) \circled4 NPLC군-적정단백 저칼슘군(protein: 200 g/kg diet, calcium: 0.1%)으로 구별하였다. 실험 종료까지의 체중은 NPLC군에서 가장 많이 증가하였으나, 실험군간의 차이를 나타내지 않았고, 식이 섭취량도 실험군간에 차이를 보이지 않았다. 뇨 칼슘배설량은 고단백군이 적정단백군보다 높은 경향을 나타내었고, HPLC군에서 유의적으로 높은 값을 보였으며 체내 칼슘보유량과 흡수율은 실험군에 따른 차이가 없었다. 뼈형성의 biomarker인 ALP의 활성은 저칼슘 식이군인 NPLC군에서 유의하게 높았고, 고단백 적정칼슘을 섭취한 HPNC군에서 유의적으로 낮았다. 혈액의 PTH 농도는 HPLC군에서 가장 낮게 나타났으며, 소변의 DPD농도는 저칼슘 식이군인 HPLC군과 NPLC군에서 높은 수치로 관찰되었고, HPNC군에서는 유의적으로 낮아졌다. 대퇴골의 건조 전의 습윤무게는 중 100 g당의 무게로 환산했을 때 NPLC군에서 가장 낮았으며 건조 후의 대퇴골의 무게 역시 다른군에 비해 NPLC군에서 가장 낮았다. 대퇴골의 회분 함량은 실험군간의 큰 차이를 나타내지 않았고, 칼슘 함량은 NPLC군과 HPLC군에서 유의하게 낮았다. 대퇴골의 골밀도는 NPNC군에서 가장 높게 나타났으며, NPC군은 가장 낮게 나타났다. 본 연구결과 고단백 저칼슘 식이 섭취시 요중 칼슘 배설량이 가장 많았고, DPD 농도가 다른 군에 비하여 유의적으로 높았으며, 골밀도도 가장 낮게 조사되어 고단백식이 섭취시 칼슘섭취 부족은 칼슘대사에 좋지 못한 결과를 나타냄을 알 수 있었다.이로 볼 때 적절한 단백질과 칼슘 섭취가 골격의 건강을 유지하고 노령화에 따른 골격질환을 예방할 수 있고, 특히 고단백 섭취시에는 칼슘영 양이 부족할 경우 골격 대사를 저해할 수 있으므로 충분한 칼슘 섭 취가 무엇보다도 중요하다고 본다.

• Journal of Nutrition and Health
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• 제24권2호
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• pp.124-131
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• 1991

식이 단백질 섭취수준 및 동·식물성 단백질 급원이 칼슘 및 인대사에 미치는 영향을 검토하기 위하여 10명의 한국성인 연성을 대상으로 26일간의 통제 식이실험을 실시하였다. 대사실험 연구는 6일간의 적응기간과 10일간의 중단백식이(60g 단백질 545mg Ca)와 10일간의 고단백질 식이(90g 단백질 575mg Ca)로 구성되었다 중·고단백 식이기간 동안 동물성 단백질(75% 동물성 단백질)과 식물성 단백질(75% 식물성 단백질) 식이군으로 나누어 같은 식이에서 중단백식이 후 고단백식이를 섭취토록 하였고 실험식이 마지막 4일간은 각 2명에게 300mg 칼슘을 보충시켰다. 칼슘 흡수율은 단백질 섭취량의 증가시 동물성 단백질 식이군에서 유의적으로 증가하였다, 칼슘 보충은 급원에 관계없이 칼슘 흡수를 증가시켰다. 중단백 식이기간 동안 동물성과 단백질 식이에서 칼슘흡수율은 약 30% 이었으며 고단백질식이 기간 동안 동물성 단백질에서 46% 식물성 단백질에서 37% 이었다. 칼슘을 보충시켰을 때 중단백 식이기간동안 칼슘 흡수율은 약 46% 이었으며 고단백 식이군에서 53%이었다 뇨중 칼슘배설은 단백질 섭취수준에는 영향을 받지 않았으나 동물성 단백질 식이에서 식물성 단백질 식이보다 칼슘배설양이 많았다. 칼슘 균형을 단백질 섭취증가와 칼슘 보충으로 호전되었다. 인의 흡수는 단백질 섭취수준에는 영향을 받지않았으며 인 섭취량에 따라 증가하였다. 인 흡수율은 동물성 단백질 식이군에서 약 77∼81% 로 식물성 단백질 식이군에서의 55∼65% 보다 높았다. 이상의 결과로 보아 단백질 섭취수준 60g에서 90g으로의 증가와 칼슘보충은 뇨중 칼슘 배설에는 영향을 주지않으며 칼슘 흡수를 증진시켜 칼슘균형을 호전시키는 것으로 나타났다.

• 한국농촌생활과학회지
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• 제6권1호
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• pp.31-39
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• 1995

This study was performed to observe how soy protein and calcium in rats fed unsaturated fat-enriched diet affect the total lipid and cholesterol contents of blood and tissues male Sprague-Dawley rats weighing approximately 220g were fed four purified diets which contained 18% (w/w) corn oil, 1% (w/w) cholesterol, two sources of protein : casein or isolated soy protein (ISP) and two levels of dietary calcium : 0.1% or 1.0%, first for four weeks (Expt. 1) and second for eight weeks (Expt. 2). The contents of total lipid, cholesterol and triglyceride in blood, liver, heart and feces were determined. After four weeks feeding, the serum lipid and cholesterol concentration was not significantly different among the groups. After eight weeks feeding, these concentrations were significantly lower in ISP-High calcium group. The serum lipid concentration was influenced by dietary protein sources and calcium levels. These results indicated that the hypolipidemic effects of soy protein and high calcium intake were partly due to decrease in lipid absorption and these effects were not detected at 4 weeks feeding but 8 weeks feeding.