• Journal of Nutrition and Health
• /
• v.19 no.1
• /
• pp.32-40
• /
• 1986

The present study conducted to examine the effects of proteins from different sources on Ca excretion in 6 healthy young adult Korean women. The subjects were given meat protein diet for 5 days and soy protein diet for subsequent 5 days. the two diets were similar in protein and Ca contents. Urinary and fecal samples were collected for the last 2 days of each diet period and were analyzed for Ca and P. The results were as following ; 1) Mean daily urinary calcium excretion was 126.5$\pm$22.70mg for meat protein diet and 83.7$\pm$17.19mg for soy protein diet and the difference was significant (P<0.025). 2) Fecal Ca excretion did not show significant difference between two experimental preiod ; 466.9$\pm$73.68 mg of meat portein diet 284.4$\pm$54.96mg for soy protein diet. 3) Three out of six subjects showed negative balance on meat protein diet, but only one showed negative balance on soy protein diet. The averageof the balances on meat protein diet was -65.4 $\pm$68.19 and that of soy protein diet was 155.3$\pm$52.28 ; the difference was significant(P<0.025). 4) Urinary P excretion tended to be higher on meat protein diet but was not significant compared to soy protein diet . Fecal P excretion was significantly higher (P<0.001) on soy protein diet. Overall P balances for meat protein diet and soy protein diet were 219.94 mg and 229.46mg respectively (P<0.05). The above results show that urinary Ca excretion was significantly higher on meat protein diet but fecal excretion did not show significant difference between meat protein diet and soy protein diet. The overall Ca balance was significantly higher on Soy protein diet compared to meat protein diet.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.23 no.6
• /
• pp.894-898
• /
• 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
• /
• v.22 no.1
• /
• pp.15-18
• /
• 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.

• Korean Journal of Poultry Science
• /
• v.34 no.3
• /
• pp.217-222
• /
• 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 the East Asian Society of Dietary Life
• /
• v.5 no.3
• /
• pp.385-394
• /
• 1995

Our previous reports on the effect of dietary protein on methanethiol, ethacrynic acid, bromobenzene and carbon tetrachloride metabolism were overall reviewed. The methanethiol, ethacrynicacid and bromobenzene treated rats showed the more severe liver damage in those fed a low protein diet than those fed a standard protein diet. These xenobiotics treated rats showed the lower content of hepatic glutathione and its conjugated enzyme, glutathione S-transferase activities in those fed a low protein diet than those fed a standard protein diet. In case of carbon tetrachloride treated rats, the liver damage was more reduced in rats fed a low protein diet than those fed a standard protein diet. Concomitantly the hepatic cytochrome P-450 content, and its decreasing rate to the control were lower in rats fed a low protein diet than those fed a standard protein diet.

• Asian-Australasian Journal of Animal Sciences
• /
• v.14 no.1
• /
• pp.70-76
• /
• 2001

This experiment was conducted to investigate the effects of crystalline isoleucine supplementation of a low protein, corn-soybean meal diet on the performance and immune function of weanling pigs. Forty-five crossbred ($Duroc{\times}Landrace{\times}Large\;White$) piglets, weighing an average of $11.00{\pm}0.07kg$, were assigned to either a control diet containing 20% crude protein (0.64% isoleucine), a 16% crude protein diet without isoleucine supplementation (0.41% isoleucine) or a 16% crude protein diet supplemented with isoleucine (0.64% isoleucine). Reducing the crude protein content of the diet from 20 to 16% significantly (p<0.05) reduced both average daily gain and feed intake. Feed conversion also tended (p=0.07) to be poorer for a low protein diet without isoleucine supplementation. Isoleucine supplementation of the 16% crude protein diet increased both gain and feed intake to a level similar to that obtained by pigs fed the 20% crude protein diet (p>0.05). Blood urea nitrogen, serum total protein and serum globulin were significantly (p<0.05) higher for pigs fed the unsupplemented 16% crude protein diet than for pigs fed the isoleucine-supplemented diet or the control. Egg albumin antibody titre decreased significantly (p<0.05) in pigs fed the diet with isoleucine supplementation, whereas the antibody titre of pigs fed the low protein and low isoleucine diet was similar to that of pigs fed the diet containing 20% crude protein and 0.64% isoleucine. It was suggested that crystalline isoleucine supplementation of a low protein and low isoleucine diet improved pig performance but suppressed humoral immune function.

• Asian-Australasian Journal of Animal Sciences
• /
• v.24 no.9
• /
• pp.1274-1281
• /
• 2011

Dietary protein restriction affects lipid metabolism in rats. This study was performed to determine the effect of a low protein diet on hepatic lipid metabolism and insulin sensitivity in growing male rats. Growing rats were fed either a control 20% protein diet or an 8% low protein diet. Feeding a low protein diet for four weeks from 8 weeks of age induced a fatty liver. Expression of acetyl-CoA carboxylase, a key lipogenic enzyme, was increased in rats fed a low protein diet. Feeding a low protein diet decreased very low density lipoprotein (VLDL) secretion without statistical significance. Feeding a low protein diet down-regulated protein expression of microsomal triglyceride transfer protein, an important enzyme of VLDL secretion. Feeding a low protein diet increased serum adiponectin levels. We performed glucose tolerance test (GTT) and insulin tolerance test (ITT). Both GTT and ITT were increased in protein-restricted growing rats. Our results demonstrate that dietary protein restriction increases insulin sensitivity and that this could be due to low-protein diet-mediated metabolic adaptation. In addition, increased adiponectin levels may influences insulin sensitivity. In conclusion, dietary protein restriction induces a fatty liver. Both increased lipogenesis and decreased VLDL secretion has contributed to this metabolic changes. In addition, insulin resistance was not associated with fatty liver induced by protein restriction.

• Journal of Nutrition and Health
• /
• v.7 no.1
• /
• pp.45-50
• /
• 1974

Biochemical studies such as growth rate, blood cholesterol and ascorbic acid contents in various organs of albino male rats were studied in the Garlic, Vitamin E, high and low protein diet fed groups. The results of this study were summarized as follows : 1) Either single 10% or 30% protein diet fed rats were not shown growth rate properly. In supplementation of Vitamin E or Garlic on 30% protein growth rate was a more increased than that of the 10% protein diet group. 2) The rate of food consumption of rats fed a 10% or 30% protein diet supplemented with Vitamin E and Garlic was more increased than that of the control Group receving 10% or 30% protein diet alone. 3) No essential difference was observed between the cholesterol level in blood of rats fed 10% protein diet supplemented with Vitamin E and Garlic and that of rats Receiving 10% protein diet alone. But the cholesterol level in blood of rats fed 30% protein diet supplemented with Vitamin E and Garlic was lower than that of control receiving 30% protein diet alone. 4) The Vitamin C contents in various organs of rats fed the diet supplemented with Vitamin E and Garlic seems to be a little higher than that of the control group fed the protein diet alone.

• Journal of the East Asian Society of Dietary Life
• /
• v.7 no.1
• /
• pp.13-20
• /
• 1997

This study was designed to determine the effects of protein sources on the curation of gastric ulceration, protein metabolism, and nitrogen balance in rats with gastric ulcer induce by restraint and water immersion stress. After the rats were fed 10% casein diet for 3 weeks, four groups of the rats were forced in 5$\times$5$\times$15cm plexiglass cage. The restraint and water immersion stress was carried at 20$\pm$2$^{\circ}C$ for 8-hour. The other one group(control group) was not exposed to stress. After stress 4 kinds of different diets containing 20% protein were given for 5 days. The protein sources were casein, whey protein, soy protein, gluten. The control group was fed to 10% casein diet. The results were as follows ; the weights of rats were not different among the diet groups During the experiment period follows ; the weights of rats were not different among the diet groups during the experiment period (for 5 days). The ulcer index of rats fed 10% gluten and soy protein diet was significantly higher than those of casein and whey protein diet groups(p<0.05). The level of serum albumin was not significantly different among diet groups. But hematocrit and the level of $\alpha$-amino-N, BU and UUN of plant protein diet groups were higher than animal diet groups, the urinary hydroxyproline of soy protein group was the highest and the whey protein was the lowest. The digestibility and BV of nitrogen of gluten diet group were significantly higher than those of casein and whey protein diet groups(p<0.05). The animal proteins had more curative effects of ulcer than plant animals. The results of this study provide useful information concerning diet therapy for the patients with gastrointestinal diseases and the field of enteral diet materials.

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