• Journal of Nutrition and Health
• /
• v.38 no.5
• /
• pp.344-351
• /
• 2005

The purpose of this study was to examine the impact of isoflavones on lipid concentrations and hepatic LDL receptor mRNA level in growing female rats. Twenty four rats (body weight $75\pm5g$) were randomly assigned to one of two groups, consuming control diet or isoflavones supplemented diet (57mg isoflavones/100g diet). All rats has been fed on experimental diet and deionized water ad libitum for 9 weeks. The concentration of triglyceride and total cholesterol were measured in serum and liver. Serum HDL cholesterol was measured. Hepatic LDL receptor mRNA level was tested by RT-PCR. Supplementation of isoflavones did not affect weight gain, mean food intake and food efficiency ratio. Serum total cholesterol and non-HDL cholesterol of isoflavones supplemented rats were significantly lower than those of control rats (p<0.05). But hepatic cholseterol was not influenced by supplementation of isoflavones. Hepatic LDL receptor mRNA level not significantly different between control group and isoflavones supplemented group. Therefore, isoflavones may be beneficial on serum cholesterol and non-HDL cholesterol lowering in growing female rats.

• Nutritional Sciences
• /
• v.9 no.2
• /
• pp.74-81
• /
• 2006

The present study examined the effect of soy isoflavones on lipid metabolism in growing female rats. Rats were randomly assigned to three different groups and provided experimental diets for 9 weeks. The experimental groups were classified into 1) a control group, 2) a soy protein isolate group: soy (+)) group and 3) a soy protein concentration group: soy (-)) group. Diets contained either casein or one of two soy proteins with (soy (+)) or without isoflavones (soy (-)). Serum triglyceride concentration showed no significant differences among the experimental groups. Serum total cholesterol concentration was significantly lower in both the soy (+) and soy (-) groups than in the control group and LDL-cholesterol concentration was significantly lower in the soy (+). Serum HDL-cholesterol concentration was significantly higher in the control group than in the soy protein groups but the HDL-cholesterol share rate in total cholesterol tended to be lower in the control group than in the soy protein groups, insignificant as it was. Hepatic IDL receptor mRNA level was significantly increased in the soy (+) group when compared to the other two groups to be 20% higher than the control group. In conclusion, soy protein isolate, soy protein rich with isoflavones reduced serum total cholesterol and LDL-cholesterol concentration and increased hepatic IDL receptor mRNA expression in growing female rats. Therefore, it is considered that the intake of soy isoflvones during puberty can be advantageous in terms of the long-tenn control of serum lipid.

• Journal of Community Nutrition
• /
• v.4 no.3
• /
• pp.195-201
• /
• 2002

The purpose of this study was to examine the effects of dietary calcium supplementation and exercise on bone mineral density and bone mineral content of growing female rats. The exercise and control group were fed a diet containing 0.5% calcium and Ca supplementation group were fed a diet containing 1.0% calcium diet. The exercise group ran on a rodent treadmill (speed of 15m/min for 30 min) three days per week during the 3-week study period. Bone mineral density (BMD) and bone mineral content (BMC) of spine and femur were determined by using dual energy x-ray absorptiometry (FIXI-mus, GE Lunar Radiation Cooperation, Madison, WI, USA). The exercise group had significantly greater (6.25%) spine BMD compared to the nonexercise group and the exercise group had but not significantly greater spine BMC (7.1%) compared to nonexercisers. Femur BMD and BMC divided by the rats final body weight appears to have a higher BMD (7.5%) and BMC (4.5%) in the exercise group, which indicates that exercise had a positive influence on femur bone mineral density and bone mineral content. The supplementation of calcium did not significantly affect spine and femoral BMC and BMD for the 3 weeks experimental period. It can be concluded that when calcium intake meets the recommended, exercise is beneficial for acquisition of spine bone mineral density in young growing female rats. (J Community Nutrition 4(3) : 195∼201, 2002)

• Journal of Nutrition and Health
• /
• v.40 no.3
• /
• pp.235-241
• /
• 2007

The aim of this study was to define an arginine effect when added to a diet. The influence of arginine supplements on bone mineral density and content were studied in young female Sprague-Dawley rats fed either an arginine supplemented diet or control diet. Twenty four rats (body weight $83{\pm}5g$) were randomly assigned to one of two groups, consuming casein or casein with supplemented arginine diet. All rats were fed on experimental diet and deionized water ad libitum for 9 weeks. Bone mineral density (BMD) and bone mineral content (BMC) were measured using PIXImus (GE Lunar Co, Wisconsin, USA) in spine and femur 3, 6, and 9 weeks after feeding. The serum and urine concentrations of Ca and P were determined. Diet did not affect weight gain and mean food intake. The serum concentration of Ca and P were not changed by arginine supplementation. Urinary Ca excretion was significantly decreased by arginine supplementation. Spine BMD was significantly increased by arginine supplementation on 3 and 6 weeks after feeding. Femur BMD was significantly increased in the group of arginine supplementation on 3, 6, and 9 weeks. Rats fed the arginine-supplemented diet had better bone mineral content than did control diet rats in the experimental period. Therefore, arginine supplementation may be beneficial on spine and femur BMD increment in growing female rats. These are thought to be associated with an arginine-induced growth hormone release. The exact mechanism of this effect remains to be elucidated.

• Journal of Nutrition and Health
• /
• v.40 no.4
• /
• pp.320-326
• /
• 2007

An important related question is whether arginine has influence bone metabolism. The effect of arginine supplements on bone markers and related hormones were studied in young female Sprague-Dawley rats fed either an arginine supplemented diet or control diet. Twenty four rats (body weight 83${\pm}$5 g) were randomly assigned to one of two groups, consuming casein or casein with supplemented arginine diet. All rats were fed on experimental diet and deionized water ad libitum for 9 weeks. Bone formation was measured by serum osteocalcin and alkaline phosphatase (ALP) concentrations. And bone resorption rate was measured by deoxypyridinoline (DPD) crosslinks immunoassay and corrected for creatinine. Serum osteocalcin, growth hormone, estrogen, insulin-like growth factor-1 (IGF-1), parathyroid hormone (PTH) and calcitonin were analyzed using radioimmunoassay kits. The weight gain and mean food intake were not affected regardless of diets. The rats fed arginine-supplemented diet had not significantly different in ALP, osteocalcin, crosslinks value, PTH, estradiol, and IGF-1 compared to those fed casein diet group. The arginine-supplemented group had significantly higher growth hormone and calcitonin than casein group. This study suggests that arginine is beneficial for bone formation in growing female rats. Therefore exposure to diet which rich in arginine early in life may have benefits for bone formation and osteoporosis prevention.

• Nutrition Research and Practice
• /
• v.2 no.2
• /
• pp.68-73
• /
• 2008

This study was focused on whether or not isoflavones affect the increase in bone mineral density of growing females. Female Sprague-Dawley rats ($60{\pm}5\;g$) were randomly assigned to two groups and provided control diets (control group) or isoflavone-supplemented diet (IF group, 57.8 mg isoflavones/100 g diet) for 9 weeks in growing female rats. Measurements of Bone Mineral Density (BMD) and Bone Mineral Content (BMC) on the experimental animals were executed in the $3^{rd}$, $6^{th}$, $9^{th}$ weeks. In result, there was no significant difference in spine BMD between the isoflavones supplemented group and the control group. But, the IF group tended to have higher BMD than the control group in between 3 and 9 experimental weeks, and the striking difference could be shown in the $6^{th}$ week of feeding. In case of femur BMD, the effects of added isoflavones appeared in the $6^{th}$ week of feeding, and it became intensified in the $9^{th}$ week of feeding to the extent that the BMD in the IF group was significantly higher than that of the control group (p<0.05). In conclusion, isoflavone supplementation increased spine BMD per weight in the $6^{th}$ week of feeding, and affected the increase of femur BMD in the $9^{th}$ week. The result of the experiment implies that it affects positively the formation of spine and femur BMD of growing female rats. The study also suggests that the effects of isoflavone on the pattern of BMD formation might differ from the parts of bones.

• Journal of Nutrition and Health
• /
• v.36 no.4
• /
• pp.359-367
• /
• 2003

The purpose of this study was to examine the impact of soy protein and soy isoflavones on bone and mineral density in young female Sprague-Dawley rats. Fifty eight rats (body Weight 75 $\pm$ 5 g) were randomly assigned to one of four groups, consuming casein, soy protein concentrate, soy protein isolate (57 mg isoflavones/100 g diet) or casein added isoflavones (57 mg isoflavones /100 g diet). All rats were fed on experimental diet and deionized water ad libitum for 9 weeks. Bone mineral density (BMD) and bone mineral content (BMC) were measured using PIXImus (GE Lunar Co, Wisconsin, USA) in spine and femur on 3, 6, 9 weeks after feeding. The serum and urine concentrations of Ca and P were determined. Diet did not affect weight gain and mean food intake. Food efficiency ratio was lower In soy protein groups. The serum concentration of Ca and P were not changed by soy protein and isoflavones. Urinary Ca and P excretion were not significantly different. Spine BMD was significantly increased by soy protein isolate on 3 and 6 weeks after feeding. Femur BMD was significantly increased in the groups of soy protein isolate and isoflavones adding on after 9 weeks. Therefore, soy protein with rich isoflavones may be beneficial on spine and femur BMD increasement in growing female rats.

• Journal of Biosystems Engineering
• /
• v.29 no.5 s.106
• /
• pp.467-474
• /
• 2004

This study was to investigate the biomechanical characteristics of isoflavone-treated ovariectomized growing rat's femur. 4-week-old Wistar (female rats were randomly divided into 5 groups and assigned to sham(SH) group, and four ovariectomized groups consisting of one ovariectomized(OVX) group and genisetin(10 mg/kg b.w. )(OVX+G), daidzein(10 mg/kg b.w.)(OVX+D), and 17 $\beta$-estradiol(10 $\mu$g/kg b.w.)(OVX+ES) in AIN-76 modified diet for 8 weeks. The OVX groups gained more body weight than the SH group. Femoral weight was increased by feeding genistein and estradiol, whereas femoral length among groups was not significantly different. The breaking farce, stiffness, deformation, and energy values of the OVX group were lower than those of other groups. The stress, strain, and Young's modulus values of the OVX group were higher than those of other groups.

• The Korean Journal of Physiology and Pharmacology
• /
• v.11 no.3
• /
• pp.129-133
• /
• 2007

There are growing evidences suggesting a pivotal role of oxidative stress in the pathophysiology of preeclampsia. We investigated oxidative stress in the rat model of preeclampsia, and in clinical cases. Pregnant female rats were injected intraperitoneally with deoxycorticosterone acetate (DOCA) and given 0.9% saline as drinking water during their pregnancy. We assessed plasma $F_2-isoprostane(8-iso-PGF_{2{\alpha})$ and malondialdehyde (MDA) in a rat model, and the same markers in the plasma of maternal blood and fetal cord blood in pregnant women with preclampsia. Blood samples from the umbilical arteries and veins were collected separately. The concentrations of MDA were increased in the preeclampsia groups of animal and humans, compared with the control group; it was significantly increased in the umbilical artery and vein of the preeclampsia group. The concentrations of $F_2-isoprostane$ were elevated in the preeclampsia groups of animal and humans, compared with the control group, and the increase in $F_2-isoprostane$ concentration was prominent in the umbilical vein than umbilical artery of the preeclampsia group. Therefore, it appears that the placenta has an important role in the pathophysiology of preeclampsia, and the $F_2-isoprostane$ of the umbilical vein may serve as a relatively reliable marker for ischemic/hypoxic injury to the fetus during the perinatal period.

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