• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.6
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• pp.894-898
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• 1994

To evaluate an effect of dietary protein on the liver damage, the bromobenzene was intraperitoneally injected to the rats fed a low or high protein diet and then the liver weight per body weight and serum levels of alanine aminotransferase (ALT) activities were determined to demonstrate the differences in liver damage between the groups fed low or high protein diet. Hepatic aniline hydroxylase (AH), glutthione (GSH) content and glutathione s-transferase(GST) activity were also determined to clarify causes of liver damage between the two groups. Increases of liver weight per body weight and serum ALT activities were higher in brombenzene treated rats fed low protein diet than those fed high protein diet. The increasing rate of hepatic AH activity was higher in bromobenzne-treated rats fed low protein diet than that in those fed high protein diet. Furthermore , hepatic glutathione contents and GST activities in bromobenzene-treated rats were higher in rats fed high protein diet than those fed low protein diet. In case of control group, the heaptic glutathione content and GST activity were also higher in rats fed high protein diet than those fed low protein diet.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.1
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• pp.15-18
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• 1993

To evaluate an effect of dietary protein on the intoxication of methanethiol in rats, the methanethiol was intraperitoneally injected to the rats fed a low or high protein diet and then the liver weight per body weight and seurm levels of alanine aminotransferase (ALT) activities were determined to investigate the differences in liver damage between the animal groups fed low protein diet and that fed high protein diet. On the other hand, the hepatic glutathione content and its conjugating enzyme, glutathione S-transferase (GST) activity were determined to clarify the cause of difference in liver function between the two groups. The increasing rate of liver weigh/body wt., serum levels of ALT to its control group were higher in methanethiol-treated rats fed low protein diet than those fed high protein diet. The hepatic content of glutathione and GST activity were higher in rats fed high protein diet than those fed low protein diet and the decreasing rate of hepatic glu-tathione content to its control group was higher in rats fed low protein diet than those fed high protein diet. Furthermore, the hepatic GST activity in methanethiol-treated rats was higher in rats fed high protein diet than those fed low protein diet. In case of control group, the GST activity was also higher in rats fed high protein diet than those fed low protein diet.

• Preventive Nutrition and Food Science
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• v.19 no.3
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• pp.156-163
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• 2014

We investigated the effects of a high-protein diet and resveratrol supplementation on immune cells changes induced by abdominal irradiation in rats. Female Wistar rats were divided into 5 groups: 1) control diet, 2) control diet with irradiation 3) 30% high-protein diet with irradiation, 4) normal diet with resveratrol supplementation and irradiation, and 5) 30% high-protein diet with resveratrol supplementation and irradiation. We measured blood protein and albumin concentrations, lipid profiles, white blood cell (WBC) counts, proinflammatory cytokine production, and splenocyte proliferation in rats that had been treated with a 17.5 Gy dose of radiation 30 days prior. A high-protein diet affected plasma total cholesterol and very low density lipoprotein-cholesterol levels, which were increased by the radiation treatment. In addition, the lymphocyte percentage and immunoglobulin M (IgM) concentration were increased, and the neutrophil percentage was decreased in rats fed a high-protein diet. Resveratrol supplementation decreased the triglyceride (TG) level, but increased the IgM concentration and splenocyte proliferation. Proinflammatory cytokine production was lower in rats fed a high-protein diet supplemented with resveratrol than in rats fed a control diet. The results of the present study indicate that high-protein diets, with or without resveratrol supplementation, might assist with recovery from radiation-induced inflammation by modulating immune cell percentages and cytokine production.

• Korean Journal of Poultry Science
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• v.34 no.3
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• pp.217-222
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• 2007

This study was conducted to investigate the effects of mud flat bacteria origin protease supplementation by crude protein level on growth performance, nutrient digestibility, total protein and BUN (blood urea nitrogen) concentration in broilers. A total of four hundred eighty broilers were randomly allocated into four treatments with six replications for five weeks. Dietary treatments included 1) high crude protein diet, 2) high crude protein diet + 0.1% protease, 3) low crude protein diet and 4) low crude protein diet + 0.1% protease. During the entire experimental period, weight gain and feed/gain were improved in treatments of high crude protein diets and low crude protein diet added protease compared with treatment of low crude protein diet without protease (P<0.05). Similarly, DM digestibility was also improved in treatments of high crude protein diets and low crude protein diet added protease compared with treatment of low crude protein diet without protease (P<0.05). N digestibility was improved in treatment of high crude protein diet added protease compared with low crude protein diet without protease (P<0.05). Total protein concentration in blood was increased in treatment of high crude protein diet without protease compared with other treatments (P<0.05). In conclusion, mud flat origin protease was effective in improving weight gain, feed/gain and nutrient digestibility, and influenced blood total protein in broilers.

• Journal of Nutrition and Health
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• v.25 no.5
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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.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.2
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• pp.127-131
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• 1993

To evaluate an effect of dietary protein on lipoprotein profile serum of carbon tetrachloride-treated rats, carbon tetrachloride (50% in olive oil) was twice given at 0.1ml/100g body weight at intervals of 24hours to the male rats and then the degree of liver damage in carbon tetrachloride-treated animals fed a low protein diet was compared with that fed a high protein diet. The increasing rate of liver weight/body weight and the serum levels of alanine aminotransferase in carbon tetrachloride-treated rats to the control group were higher in rats fed high protein diet than those fed low protein diet. In the serum levels of lipid (total lipid, total cholesterol and triglyceride) remarkable differences were not found between low protein diet group and high protein diet group. But these serum lipids in carbon tetrachloride-treated rats were decreased and the decreasing rate of serum lipids to control group were higher in carbon tetrachloride-treated rats fed high protein diet than those fed low protein diet. Under the animal model as identified by the present data herein, serum pre $\beta$-lipoprotein and $\alpha$-lipoprotein fractions were decreased in carbon tetrachloride-treated rats, but the serum levels of $\beta$-lipoprotein were rather increased in the both group by the injection of carbon tetrachloride. Especially, the decreasing rate of $\alpha$-lipoprotein fraction was higher in $CCl_4$-treated rats fed a high protein diet than those fed a low protein diet to its control group and the increasing rate of serum $\beta$-lipoprotein fraction was also higher in $CCl_4$-treated rats fed high protein diet than those fed low protein diet.

• Journal of Nutrition and Health
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• v.22 no.4
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• pp.223-236
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• 1989

To evaluate the differences of the levels and sources of protein intake human protein metabolism, an 26-day metabolic balance study was conducted in 10 healthy Korean adult females. In the pre-study, the subjects recorded their own diets for 3 days. The metabolic balance study consisted of 6-day adaptation period, 10-day moderate protein period(60-65g/d) and 10-day high protein period(90-95g/d). During the moderate and high protein period, 5 subjects were fed the higher animal protein meals and the other 5 subjects were fed the high plant protein meals. Body weight, nitrogen balance and blood chemistries were monitored through out the study. The urine volume were sighificantly larger in the animal protein group and, the dietary fiber and fecal weights were significantly heavier in the plant protein diet group. But no statistically significant differences were found between the two dietary groups in apparent nitrogen digestability, urinary nitrogen excretion and nitrogen balance. Body weight, serum protein, albumin and HDL-cholesterol levels were not changed, but serum total cholesterol level in the animal protein diet group was elevated significantly from 143.8mg/dl on moderate potein diet to 173.0mg/dl on high proetin diet. In conclusion, from the observation of this short-term N balance study, plant diet on the adequate level of calorie and protein intake had almost the same effect of animal protein diet for protein maintenace in adults.

• Journal of Nutrition and Health
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• v.26 no.7
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• pp.851-857
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• 1993

Atherosclerotic vascular disease is a major cause of the increased morbidity and mortality assciated with diabetes mellitus. The prominent role of nutrition in hypercholesteolemia and atherosclerosis is generally accepted. Diet is a key element in the management of diabetes (type I-IDDM), yet the appropriate diet for patient with diabetes mellitus is not well known. Dietary protein has been shown to have a significant effect on plasma cholesterol levels in both experimental animals and humans. The present experiment was designed to determine the effect of the dietary protein level(20% vs 60%) on plasma glucose concentration, lipids profile, insulin and glucagon levels from non-diabetic and streptozotocin-induced diabetic rats. Results showed that a high protein diet decreased triglyceride concentration in diabetic rats. Also diabetic rats fed a high protein diet were hypocholesterolemic than rats fed a control diet. There were no effects by level of protein on fasting blood glucose concentration and insulin/glucagon ratio. Results from the present study suggest that a high protein diet may be beneficial to control pasma lipids in chemically-induced diabetic rats.

• Journal of Nutrition and Health
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• v.27 no.9
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• pp.883-891
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• 1994

The number of diabetics in Korea is about 3 to 5 percent of the population, and the incidence is increasing yearly due to changes of life style and food intake. Diet is a key element in the management of diabetes, yet the appropriate diet for diabetes remains controversial. We have recently shown that a diet rich in protein of animal origin(casein) seems beneficial to controling plasma glucose and lipids in streptozotocin-induced diabetic rats. It therefore seemed desirable to find out whether the beneficial effect of high casein diet in experimental diabetes could also be reproduced with a vegetable source of protein(soy). The purpose of this study is to compare these results with the results of our previous study. In the present study, non-diabetic and streptozotocin-induced diabetic rats were studied in order to examine the effects of altering the level(20% vs 60%) of dietary soy protein on blood glucose, lipids, and hormones. Results of the present study showed that a high soy protein diet decreased triglyceride concentration in diabetic rats. However, diabetic rats fed a high soy protein diet were not hypocholesterolemic compared to rats fed a control diet. Moreover, diabetic rats fed a high soy protein diet had significantly increased plasma glucose concentration compared to rats fed a control diet. This study was not able to discern a specific effect of dietary protein level on insulin, glucagon, or insulin/glucagon ratio. Except for the hypotriglyceridemic effect, the results were not similar to the findings of our previous study which showed a beneficial effect on streptozotocin-induced diabetic rats fed a high casein diet.

• Journal of Nutrition and Health
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• v.1 no.2
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• pp.61-85
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• 1968

The experiment was carried out on eight healthy male subjects of 19-22 years old and they were maintained The experiment was carried out on eight healthy male subjects of 19-22 years old and they were maintained under the rice diet, the general mixed diet and the high animal protein diet for 7 days of each experimental period, respectively. The composition of each diet was indicated in Table 3. The allowance' of each nutrient per head per day in each diet were as follows. a) In the rice diet; protein:139.5 g (animal source:64.6 g, vegetable source:74.9 g), fat:25.3 g (animal source:11.3 g, vegetable source:14.0 g), carbohydrate: 644.0 g, calcium:982.3 mg, phosphorus: 2369.2mg, thiamine:2.1 mg, riboflavin: 1.6 mg, and 3211 Cal. b) In the general mixed diet; protein: 97.4g (animal source: 10.5 g, vegetable source: 86.9 g), fat:40.3 g (animal source:7.1 g, vegetable source:33.2 g), carbohydrate:620.7 g, calcium:887.1m g, phosphorus:2200.8m g, thiamine: 1.8m g, riboflavin:1.9m g, and 3158 Cal. c) In the high animal protein diet; protein: 135.6 g (animal source:68.8 g, vegetable source:66.8 g), fat:32.5g (animal source:17.9 g, vegetable source:14.6 g), carbohydrate:930.9 g, calcium: 626.0 mg, phosphorus: 1998.9 mg, thiamine: 1.5 mg, riboflavin: 1.5 mg, and 3194 Cal. The absorption rates of protein, fat, carbohydrate, calcium, phospherus, thiamine and riboflavin in each diet were observed. The results obtained were summarized as follows: 1. The absorption rates of protein and fat in the rice diet were 88.t % and 71.3.%. 2. The absorption rates of protein and fat in the general mixed diet were 83.4% and 86.4%. 3. The absorption rates of protein and fat in the high animal protein diet were 86.8% and 82.4%. 4. The nitrogen balances in the rice, the general mixed and the high animal protein diet groups were +5.7g, +2.3g and +4.0g respectively. 5. The absorption rates of carbohydrate in each diet were all above 95 % and so seemed to be almost completely absorbed except the cellulose in the diets. 6. The calory utilization rates in each diet were all above 93 %. 7. The minimum absorption rates of protein, fat and calory were 83.8%, 63.3%, and 89.7% in the rice diet, 80.0%, 80.9% and 85.9%, in the general mixed diet and 83.6%, 75.7% and. 89.3 % in the high animal protein diet respectively. Therefore, it is assumed that these data might be significant in practical use. 8. The protein absorption rates of the rice diet (88.1 %) was better than that of the general mixed diet (83.4 %). 9. The fat absorption rates of the general mixed diet and the high animal protein diet (86.4% and 82.4%) were signficantly better than that of the rice diet (71.3%). 10. The calcium absorption rates of each diet, rice diet, the general mixed diet and the high animal protein diet were 41.6%, 36.0%, and 27.7%, respectively. 11. The phosphorus absorption rates of each diet were 51.4%, 56.0% and 52.3%, respectively.12. The phosphorus absorption rate seemed better than that of calcium. 13. The thiamine absorption rates of each diet seemed 27.0 %, 42.9 % and 29.5 %, respectively. 14. The riboflavin absorption rates of each diet seemed above 30.6%, 27.1%, and 39.3% respectively. 15. The excretion amounts of thiamine or riboflavin were much more than the amounts ingested of the both vitamins. Therefore, the certain amount of both vitamins seemed to synthesize in the intestine.