• 대한치과교정학회지
• /
• 제19권3호
• /
• pp.15-33
• /
• 1989

The purpose of this study was to investigate changes of the mandible of a growing rat when they are subjected to a retractive force and those after removal of the retractive force. The experimental animals were Sprague-Dawley male rats of four weeks of age. A mandible was retracted with 50 grams of force on each side in the posterior and superior direction for 8 hours per day. The animals were sacrificed after 1 week, 2-week and 4-week force application, and after 4-week force application-4-week force removal period. The changes of rat mandibular growth following retractive force on the growing rat mandible were observed histologically and biometrically. The findings were as follows ; 1. Histologically, the thickness of the condylar cartilage was slightly reduced in the anterosuperior region with the retractive force. However, in the group of 4-week force application-4-week force removal, there was no significant difference in the thickness of the condylar cartilage. 2. There were no significant histological changes in the articular disk and glenoid fossa through the experimental period. 3. The length and anterior height of the mandible subjected to the retractive force were significantly smaller and greater than those of the control group. 4. There were no significant differences in the mandibular length between 4-week force application - 4-week force removal and the control group. 5. It was concluded that a mandibular retractive force produced inhibitory effects in the growth of the mandible, but that these effects were not sustained during mandibular growth in this experimental model.

• Journal of Community Nutrition
• /
• 제6권1호
• /
• pp.48-54
• /
• 2004

The purpose of this study was to examine the effects of dietary protein and exercise on bone mineral density and bone mineral content of growing male rats. Forty male, Sprague-Dawley rats(age 21 days) were assigned to four groups that underwent 9 weeks of experimental treatment. Animals were assigned to one of two exercise treatments (treadmill running or sedentary). The exercise and nonexercise group were fed a diet containing casein or soy with rich isoflavones (3.4mg/g protein). The exercise group ran on a rodent treadmill(speed of 15m/min for 30min) three days per week during the 9-week study period. All rats were fed an experimental diet and deionized water ad libitum for 9 weeks. Total bone mineral density (BMD), total bone mineral content (BMC), total body calcium, spine BMD and BMC, and femur BMD and BMC were determined by using dual energy x-ray absorptiometry (FIXI-mus, GE Lunar Radiation Cooperation, Madison, WI, USA). The soy diet group appears to have a significantly higher total BMD/weight and total BMC/ weight, spine BMD/weight, spine BMC/weight, femur BMD/weight and femur BMC/weight compared to the casein group in nonexercise and exercise. The exercise group had significantly greater total BMD/weight and BMC/ weight, spine BMD/weight and BMC/weight, femur BMD/weight and BMC/weight compared to the nonexercise group when the protein source was casein. The exercise combined soy group had significantly greater total BMD/weight and BMC/weight, spine BMD/weight and BMC/weight, femur BMD/weight and BMC/weight, compared to the exercise combined casein group. The results indicate that exercise had a positive influence on bone mineral density and bone mineral content and soy significantly affect on bone mineral density and bone mineral content for the 9 weeks experimental period. It can be concluded that exercise combined with a soy diet is most beneficial for acquisition of spine bone mineral density in young growing male rats. This convincing evidence suggests that a change in life style such as increasing exercise and consumption of soy protein is a practical strategy for significantly reducing the incidence of osteoporosis.

• Clinical and Experimental Reproductive Medicine
• /
• 제39권4호
• /
• pp.144-152
• /
• 2012

Objective: Concerns are growing about the decrease in male reproductive health. Caffeine is one of the popular nutrients that has been implicated as a risk factor for infertility. In the present study, we examined whether in utero and lactational exposure to caffeine affects the reproductive function of the offspring of rats. Methods: Pregnant rats received caffeine via drinking water during gestation (26 and 45 mg/kg) and lactation (25 and 35 mg/kg). Body and reproductive organ weight, seminiferous tubule diameter, germinal epithelium height, sperm parameters, fertility rate, number of implantations, and testosterone level of the offspring were assessed from birth to adulthood. Results: Significant dose-related decreases were observed in the body and reproductive organ weight, seminiferous tubule diameter, and germinal epithelium height of the offspring. Sperm density had declined significantly in offspring of the low-dose and high-dose groups, by 8.81% and 19.97%, respectively, by postnatal day 150. The number of viable fetuses had decreased significantly in females mated with male offspring of the high-dose group at postnatal days 60, 90, 120, and 150. There were also significant reductions in testosterone levels of high-dose group offspring from birth to postnatal day 150. Conclusion: It is concluded that maternal caffeine consumption impairs gonadal development and has long-term adverse effects on the reproductive efficiency of male offspring rats.

• Journal of Nutrition and Health
• /
• 제5권4호
• /
• pp.177-187
• /
• 1972

곡식의 혼합비율은 백미에 보리쌀과 밀쌀을 각각 15%, 30%, 45%의 비례로 혼합하였고 비교군으로써 순백미군과 20% sugar casein diet를 두어서 총 8 group 으로 나누었다. 흰쥐 생후 $45{\pm}5$ 일(日) 된 albino rat로써 initial body weight 가 male이 $58{\pm}2\;g$, female이 $62{\pm}2\;g$ 이 되는 80 마리의 쥐를 8 군으로 하여서 한 군에(female 5, male 5)씩 나누어서 총 14주일 사육하였다. 성장율, 식이섭취량, F.E.R. P.E.R. 를 비교하여 보면 순백미 또는 백미에 보리를 혼합한 군보다 백미에 밀쌀을 섞은 군이 더 좋은 성장율과 F.E.R. 및 P.E.R. 을 나타내 주었다. 이와 같은 경향은 male군인 경우 female군보다 더 현저하나 nitrogen retention 에 역시 밀쌀 혼합군이 백미군이나 백미에 보리쌀을 혼합한 군보다 현저히 우수함을 볼 수 있으며 몸무게 증가와 밀접한 관계를 지니고 있음을 볼 수 있다. 곡류 diet 에서 배설된 nitrogen 중 $10{\sim}20%$가 변으로 배설되는 반면 표준군인 경우 nitrogen 이 거의 urine 으로 배설됨을 볼 수 있다. 이와 같은 결과는 곡류식인 경우는 함유된 단백질이 동물성 단백질식이에 비해 소화흡수되는 율이 저조하다. 혈청내 glucose 는 몸무게 증가와 밀접한 관계가 있었다. cholesterol 은 표준군이 곡류 diet 보다 total cholesterol 함량이 감소했으나 esterified cholesterol 과 free cholesterol 의 비에서 보면 곡류식이군이 표준군보다 높았다. 본 연구에서는 nitrogen 의 배설 상태 및 몸무게증가현상으로 미루어 밀쌀 혼합군이 보리쌀 혼합군보다는 우수하다는 결론을 지을 수 있다.

• 한국수정란이식학회지
• /
• 제31권3호
• /
• pp.169-177
• /
• 2016

There is a growing interest in the application of primary hepatocytes for treatment of liver diseases in humans and for drug development. Several studies have focused on long-term survival and di-differentiation blocking of primary hepatocytes in an in vitro culture system. Therefore, the present study also aimed to optimize an in vitro culture system using primary rat hepatocytes. Primary rat hepatocytes from 6-week-old male Crl:CD rats were isolated using a modified two-step collagenase perfusion. Healthy $3.5{\times}10^6$ primary rat hepatocytes were seeded into a 2 dimensional (2D) culture in a 25T culture flask coated with collagen type I or into a 3D culture in a 125-ml spinner flask for 7 days. Production of plasma protein (ALB and TF), apoptosis (BAX and BCL2), and CYP (CYP3A1) related genes were compared between the 2D and 3D culture systems. The 3D culture system had an advantage over the 2D system because of the relatively high expression of ALB and low expression of BAX in the 3D system. However, the level of CYP3A1 did not improve in the 3D culture with and without the presence of a dexamethasone inducer. Therefore, 3D culture has an advantage for albumin production and primary rat hepatocyte survivability, but a low expression of CYP3A1 indicated that primary rat hepatocytes require a high-density culture for stress reduction by continuous flow.

• 생약학회지
• /
• 제39권2호
• /
• pp.80-85
• /
• 2008

Benign prostatic hyperplasia (BPH) is one of the common diseases in elderly men. Recently, the old-aged population has increased, with the interest in the clinical importance of BPH ever growing. This study is designed to investigate the effects of KH-305 on BPH induced rat. The herb formulation KH-305 is consisted of Rubus coreanus, Cornus officinalis and Cuscuta chinensis. An experimental prostatic hyperplasia was induced in male rats by the administration of testosterone propionate, 3 mg/kg SC, for 2 months. The rats were divided into 3 experimental groups: the control, BPH-induced, oral KH-305 ingestion group. After 2 months, the prostates were removed, and analyzed for their prostatic weight and histological examination. The prostate weights were measured in each group, and found to be 820${\pm}$38mg, 3140${\pm}$26mg, 1880${\pm}$21mg in the control, BPH-induced, and oral KH-305 ingestion group, respectively. The BPH induced group showed statistically significant increases in their prostatic weights compared with control group(p<0.05) but oral KH-305 ingestion group showed more significant decreases than BPH-induced group statically(p<0.05). Histologically injected testosterone lead to prostatic hyperplasia in rats, but oral KH-305 ingestion decreased this change. These results suggest that KH-305 may be effective in treatment of BPH, and complementary medicine of BPH.

• 한국식품영양과학회지
• /
• 제16권2호
• /
• pp.63-68
• /
• 1987

The effects of various levels of copper(Cu) intake on the concentrations of copper, iron (Fe) and 3inc(Zn) in rat tissues were studied in growing rats. For different groups the drinking water was supplemented with 0(control), 25, 50, 100 and 200ppm Cu(as copper sulphate) for 1 day respectively. All animal groups were fed with the control diet (Cu contents, 12.8%mg/kg diet) during the experiment. At the end of the 4 week experiment, body weight gain was slightly lower in the Cu supply groups than in control group. Liver and serum Cu were significantly higher in 50, 100 and 200ppm Cu of male and in 200ppm Cu of female than in control groups. Spleen Cu was significantly increased by the supplementation of Cu. Liver and heart Fe of male and heart Fe of female were increased by incresing supplementary Cu levels. In 50ppm Cu group, liver, spleen and kidney Fe of female increased but the others did not. Fe of tissues was different in male and female rats according to Cu levels supplied. Serum Zn of male and female was significantly lower in 50, 100 and 200ppm Cu groups than in control and 25ppm Cu groups. When supplemented with Cu levels there were no significant differences among groups for liver, kidney, spleen and heart Zn as well as heart and kidney Cu.

• 한국식품영양과학회지
• /
• 제11권1호
• /
• pp.57-68
• /
• 1982

사료의 단백질과 에너지 수준이 흰쥐의 성장 및 체조성에 미치는 영향을 알기 위해서 생후 3주된 Sprague-Dawley계 albino rat 암수 각각 100마리에서 표준사료를 5일동안 급여한 후 암쥐는 체중이 $70{\sim}80g$되는 것으로 93마리를 선택하였다(3마리는 개시기 도체분석에 사용하였으며, 90마리는 사양실험에 사용하였음). 실험사료의 에너지 수준은 ME를 저에너지(3200kcal/kg), 중에너지(3600kcal/kg), 고에너지(4000kcal/kg)로 달리했으며, 단백질 수준은 ME 3600kcal/kg에 대해서 저단백질(15%), 중단백질(25%), 고단백질(35%)의 3수준으로 하고, 지방수준은 ME 3600kcal/kg에 대해서 저지방(10%), 중지방(20%), 고지방(40%)의 3수준으로 정하고 나머지 에너지는 전분과 포도당으로 보충한 9종의 사료처리구에 대한 사양실험, 및 도체분석 실험을 실시했던 바 얻어진 결과를 요약하면 다음과 같다. (1) 증체량은 암수 모두 저단백질 수준(13%)에서 가장 높았으며, 암쥐의 경우 증체량이 가장 큰 것은 LP-HE구(121g)였고, 숫쥐의 경우 LPME(210g)로서 사료의 에너지 수준에 따라서 암수의 최대증체량은 달랐다 이 결과에서 성장을 위해서 숫쥐는 NRC(1980) 사양 표준 에너지(3600kcal/kg)에 적합하나 암쥐는 더 많은 사료 에너지의 요구됨이 시사되었다. 8주간 성장 곡선을 보면 암수간에 상당한 차이를 보였으며 암쥐는 3주까지, 숫쥐는 5주까지 급격한 성장을 보였고, 그 이후부터는 완만한 성장율을 나타냈다. 또한 증체량에 대한 사료중 영양소 수준의 효과가 암쥐에서 보다 수쥐에서 더욱 예민하게 나타났다. 이 결과에서 사양실험에 적합한 실험동물은 암쥐보다 숫쥐가 더욱 효과적이라 생각되었다. 사료섭취량은 증체량 사이에 밀접한 관계가 있음을 나타냈다. 사료효율은 암쥐의 경우 단백질과 에너지 수준이 NRC(1980) 사양표준치에서 가장 높은 사료효율을 나타냈다. 단백질 효율은 암수 모두 저단백질 수준에서 가장 높았으며 에너지 수준은 암쥐의 경우 고에너지 수준에서, 숫쥐의 경우 중에너지 수준에서 가장 높은 단백질 효율을 나타냈다. 사료의 단백질과 에너지 수준이 흰쥐의 성장에 미치는 영향을 보면 사료효율 및 단백질 효율은 증체량에 직접적인 영향을 미친다. 증체량은 사료의 섭취량에 영향을 받기보다는 사료의 조성에 영향을 받는 것으로 생각되며 특히 에너지 수준에 따라 크게 영향을 받는다. (2) 체조성에 관하여 체수분과 체단백질은 암수 모두 사료 단백질 수준에 의해서 차이가 없었다. 체지방은 암쥐의 경우 사료 단백질과 에너지 수준이 증가할수록 뚜렷하게 증가했으나 숫쥐의 경우 단백질 및 에너지 수준에 의해서 큰 차이가 없었다. (3) 이상으로 본 실험결과를 종합하여 볼 때 암수의 성장곡선간에는 상당한 차이가 있었으며, 최대 증체량은 암쥐의 경우 단백질 수준 13%, 에너지 수준 3600kcal/kg으로 구성된 사료에서 얻어졌으며, 암수 각각 이 수준의 사료에서 또한 가장 높은 사료 효율 및 단백질 효율을 보였다. 이러한 사료의 조성은 암쥐의 경우 단백질 수준은 NRC 사양 표준치 이상에서 숫쥐의 경우 단백질과 에너지 수준이 모두 NRC 사양표준치에 일치했다.

• 한국식품영양과학회지
• /
• 제12권3호
• /
• pp.264-272
• /
• 1983

실험식이의 에너지수준은 저에너지(3,200kcal/kg) 중에너지(3,600kcal/kg), 고에너지(4,000kcal/kg)로 달리했으며, 저단백질(15%), 중단백질(25%), 고단백질(35%)의 3수준으로 하고, 지방수준은 ME 3,600kcal/kg에 대해서 저지방(10%), 중지방(20%), 고지방(40%)의 3수준으로 정하고 나머지 에너지는 전분과 포도당으로 보충한 9종의 식이에 대한 대사실험 결과를 요약하면 다음과 같다. 1. 고형물 조단백질 조지방, 탄수화물의 소화율은 저에너지 수준에서 중 고에너지 수준에서보다 훨씬 낮았으며, 중 고에너지 수준사이에 큰 차이가 없었다. 단백질 수준이 높아질수록 고형물과 탄수화물의 소화율은 약간씩 감소되는 경향이었으며, 단백질의 소화율은 증가되는 경향이었다. 조지방의 소화율은 식이 단백질의 영향을 받지 않았으나 에너지 수준이 높을 때 즉 식이에 포함된 지방함량이 높을 때 증가되었으며 암수 모두 같은 경향을 보였다. 각 영양소의 소화율은 고형물 약 83%, 조단백질 90%, 조지방 96%, 탄수화물 93%로서 단백질과 에너지 수준에 따라 거의 차이가 없었으며 암수 간에는 차이가 없었다. 2. 질소 축적율은 암수 모두 식이 단백질 수준이 증가할수록 감소되는 반면 식이 에너지 수준이 증가할수록 증가되는 것을 볼 수 있었다. 따라서 단백질 수준은 NRC 사양 표준치에서, 에너지 수준은 그 이상에서 암수 모두 질소 축적율이 가장 높았다. 3. 에너지 이용율은 암쥐의 경우 식이 단백질 수준이 증가할수록 감소되었으며 식이 에너지 수준이 증가할수록 증가되었다. 숫쥐의 경우 식이 단백질 수준이 증가함에 따라 감소되었으나, 암쥐와는 달리 중에너지 수준에서 가장 높았다. 즉 단백질 수준은 암수 모두 NRC 사양 표준치에서 에너지 대사율이 가장 높았으나 에너지 수준은 암쥐의 경우 NRC 사양 표준치 이상에서, 숫쥐의 경우 NRC 사양 표준치에서 각각 가장 높았다.

• Reproductive and Developmental Biology
• /
• 제34권2호
• /
• pp.89-94
• /
• 2010

Melatonin is induced by light information through the retina and leads to growth factor activation. Thus, we investigated the effects of melatonin by controlling the photoperiod of growing young rats. Male Sprague-Dawley rats (n=6; 4 weeks old) were divided into two experimental groups: the L/D group (normal photoperiod; light/dark: 12/12 h; lights on at 9:00 a.m.) and the L/L group (light/light: 24 h). Rat body weight and food consumption were measured daily for 8 weeks. After 8 weeks, the rats were anesthetized with a mixture of ketamine (50 mg/kg) and xylazine (10 mg/kg) and sacrificed. Tissue was then collected for RNA isolation (from brain, heart, liver, kidney, adrenal gland, testis, tibia, hind limb muscles). Also, serum was isolated from blood using a centrifugal separation. The L/L group had significantly lower body weight than the L/D group from 4 to 6 weeks (p<0.05). The L/D group had increased tissue mass, compared with the L/L group, but the difference was not statistically significant. The L/D group had a significantly higher melatonin concentration than the L/L group between the hours of midnight and 2:00 a.m (p<0.01). These results indicate that photoperiod length may affect the secretion of melatonin from the pineal gland. Also, the reduction of nocturnal melatonin secretion may retard the development of growing young rats. In future studies, we plan to compare exogenous melatonin administration with endogenous melatonin concentration induced by photoperiod control. Moreover, we will confirm whether the effects seen in pathological animal models can be reversed by controlling the photoperiod.