• Journal of Nutrition and Health
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• 제26권7호
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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.

• 대한화학회지
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• 제15권2호
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• pp.69-84
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• 1971

An analysis of the free amino acid contained in the plasma and erythrocytes of the six groups of Wistar Strain male adult rats (body weight 200-300g) having fasted for sixteen hours was made by means of the HITACHI Amino Acid Autoanalyzer and the result of which was corrected with RC-24B TOMY Micro Hematocrit Centrifuge. There was a depression of the plasma and erythrocytes free amino acid level on the no-protein diet with ad libitum feeding. But on the 20% casein diet there was an elevation in the levels of free amino acid and consequently alanine, glysine, lysine, serine and arginine level in the erythrocytes and threonine, glutamic acid and taurine level in the plasma increased on the high protein diet. There was more plasma and erythrocytes free amino acid level on the 5% casein- 30% fat diet than on the 5% casein-no fat diet with pair-feeding. In comparison, on the low calorie diet more free amino acids were found in plasma than in erythrocytes, but on the higher calorie diet more free amino acids were found in the erythrocytes than in the plasma. On the 20% casein-30% fat diet with pair-feeding the erythrocytes free amino acids level increased but in plasma free amino acids level decreased. Such as an opposite result was given in plasma and erythrocytes free amino acids level. In the pair-fed four groups, erythrocytes per plasma generally increased in the rate of less than 10.0 as the calorie increased. The essential amino acid per non essential amino acid generally increased in the ratio as protein level and calorie increased, and that ratio range was from 0.2 to 0.7. And essential amino acid per non essential amino acid of plasma was higher than that of erythrocytes.

• Preventive Nutrition and Food Science
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• 제7권2호
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• pp.184-187
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• 2002

Blood products from slaughterhouses that are not hygienically prepared for disposal or food consumption pose a human health hazard. Gamma irradiation is an effective method for sterilization of blood products, but may introduce changes in the molecular characteristics of proteins. This study evaluated the effects of irradiation on animal plasma proteins. Bovine and porcine blood was obtained from a slaughterhouse and the plasma proteins purified and lyophilized. The secondary structure and molecular weight distribution of the plasma protein solutions and powders were examined after ${\gamma}$-irradiation at 1, 5, 7 and 10 kGy. Gamma-irradiation affected the molecular properties of the protein solutions, but not the protein powders. Circular dichroism and sodium dodecyl sulfate-polyacrylamide gel electrophoresis studies showed that increased doses of ${\gamma}$-irradiation decrease the ordered structure of plasma proteins in solution, and cause initial fragmentation of the polypeptide chains and subsequent aggregation.

• Asian-Australasian Journal of Animal Sciences
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• 제13권11호
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• pp.1568-1575
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• 2000

Growing pigs (N=25; 18 kg) were used to study effects of L-carnitine and protein intake on plasma carnitine, energy and carnitine balance, and carnitine biosynthesis. Corn-soybean meal basal diets containing low or high protein (13.6% or 18%) were formulated so that protein accretion would be limited by metabolizable energy (ME). Each basal diet was supplemented with 0 or 500 mg/kg L-carnitine and limit fed to pigs for 10 d in a balance trial. Final carnitine concentration was compared with weight/age matched pigs measured on d 0 to calculate carnitine retention rates. Supplementation of carnitine increased (p<0.01) plasma free carnitine (by 250%), short-chain (by 160%) and long-chain acyl-carnitine concentrations (by 80%) irrespective of blood sampling time (p<0.01). The proportion of long-chain carnitine esters decreased by 40% (p<0.01) by carnitine supplementation; whereas, the proportion of short-chain acyl-carnitine concentration was not changed (p>0.10). All criteria of energy balance were unaffected by L-carnitine (p>0.10). Total body carnitine retention was increased by 450% over unsupplemented controls (p<0.01). Carnitine biosynthesis rates in pigs fed diets without L-carnitine were estimated at 6.71 and $10.63{\mu}mol{\cdot}kg^{-1}{\cdot}d^{-1}$ in low protein and high protein groups, respectively. In supplemented pigs, L-carnitine absorption and degradation in the intestinal tract was estimated at 30-40% and 60-70% of L-carnitine intake, respectively. High protein feeding effect did not affected plasma carnitine concentrations, carnitine biosynthesis or carnitine retention (p>0.10). We conclude that endogenous carnitine biosynthesis may be adequate to maintain sufficient tissue levels during growth, but that supplemental dietary carnitine (at 500 ppm) sufficiently increased plasma acyl-carnitine and total body carnitine.

• BMB Reports
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• 제34권4호
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• pp.329-333
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• 2001

Active lipoprotein lipase (LPL) is known as a noncovalent homodimer of identical subunits, and dissociation of the dimer to a monomeric form renders the lipase inactive. In this study, the oligomerization status of LPL in human and rat plasma was investigated. The LPL activity was barely detectable in the control rat and human plasma. After the injection of heparin, the total lipolytic activity of plasma was rapidly increased, and reached its maximum in 30 min. Changes of the LPL protein correlated well with those of lipolytic activity. The LPL protein that is released by heparin into both human and rat plasma was active and dimeric in the sucrose density gradient ultracentrifugation. In control rat plasma, LPL was inactive, and a great fraction was present as an aggregate. However, the inactive LPL protein in the control human plasma retained the dimeric state, indicating that dimerization can be an entity independent of the catalytic activity of LPL. The released LPL is transported as a complex with lipoproteins in plasma. Lipoprotein profiles, determined by NaBr ultracentrifugation, exhibited typical LDL- and HDL-mammal patterns in humans and rats, respectively, with a smaller amount of the LDL fraction observed in rats. The difference in the lipoprotein profiles might influence the fate of the released LPL in plasma.

• 한국식품과학회지
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• 제25권3호
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• pp.295-298
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• 1993

식품산업 특히 육가공산업에 돈혈액의 이용을 위하여 가열온도 가열시간 및 단백질 농도가 혈장단백질과 근원섬유단백질 혼합물의 gel 특성과 열안정성에 어떠한 영향을 미치는지를 규명하기 위하여 실시되었다. 혈장단백질과 혼합물(plasma+myofibrillar protein)의 용해성은 가열온도가 $70^{\circ}C$에서 $90^{\circ}C$로 증가함에 따라 크게 감소하였으며, 근원섬유단백질은 $40{\sim}60^{\circ}C$에서 용해성이 서서히 감소하였다. 또한 gel 강도와 혼탁도는 이 온도범위에서 크게 증가하였다. 가열온도 $75^{\circ}C$에서 가열시간이 경과함에 따라 혈장단백질과 혼합물의 용해성은 감소하였으나 gel 강도와 혼탁도는 증가하였다. 근원섬유단백질은 $75^{\circ}C$에서 가열시간이 경과함에도 용해성, 혼탁도, gel 강도의 변화가 거의 나타나지 않았다. 근원섬유단백질, 혈장단백질, 혼합물의 gel 강도는 단백질 농도가 5%에서 9%로 증가함에 따라 증가하였다.

• 대한의생명과학회지
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• 제6권4호
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• pp.237-244
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• 2000

정자의 원형질막은 삼투압에 의해서 영향을 받는다고 보고되고 있다. 이중 세포막내 분자구조의 변화 특히 막지질 구조의 변화와 동반되는 이온채널의 변화 그리고 $Ca^{2+}$과 HCO$^{-}_{3}$의 유동성과도 밀접한 관련이 있는 것으로 보고되고 있다. 지금까지의 연구보고에 의하면, 정자의 첨체반웅 (acrosome reaction)이 일어날 경우 protein tyrosine phosphorylation이 증가되는데 이것은 cAMP, protein kinase A 둥을 통하여 작용되는 것으로 보고되고 있다. 막의 지질변화를 유도하는 물질로 일종의 sterol acceptor인 BSA가 알려져 있는 바, 실제로 BSA가 막지질 성분에 미치는 영향을 관찰한 결과 cholesterol이 유출되고 이온 둥의 유동성 변화가 일어나, 이 유동성 변화가 정자의 adenylyl cyclase를 활성화시켜 cAMP를 증가시키고, PKA가 활성화되어 결과적으로 protein tyrosine phosphorylation이 유도된다고 보는 것이다. 첨체반응과 protein tyrosine phosphorylation과는 밀접한 관계가 있는 것으로 사료되고 있다. 본 연구는 정자 원형질막에서 cholesterol이 유출되어 protein tyrosine phosphorylation이 유도될 때, BSA와 같은 sterol acceptor가 작용할 것이라는 전제하에, 고삼투압 하에서 탈수로 인해 원형질막이 위축되더라도 sterol acceptor가 존재한다면 막지질 성분의 구조적 변화가 억제될 수 있을 것이라는 가설을 설정하였다. 실험결과, 저온 및 고삼투압 하에서 정자운동은 감소되지만 원형질막의 구조적 변화는 없고, 삼투압에 대한 반응정도는 원형질막을 통한 수분이동과 세포공적 변화에 따라 비례적으로 일어난다고 하는 사실을 발견하였다. 이 결과는 정자보존에 있어서 저온변화에 영향을 미치는 여러 인자들 특히 protein tyrosine phosphorylation의 증가와 밀접한 관계가 있음을 시시해 준다. 또한 sterol acceptor로 알려진 BSA는 삼투압이 변화되더라도 역시 중요한 인자로 작용할 수 있음을 알 수 있었으며, 특히 고삼투압으로의 변화는 cAMP와 protein kinase A를 거치는 신호전달과정에 있어서 중요한 요인이라는 사실을 확인할 수 있었다.

• BMB Reports
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• 제28권6호
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• pp.504-508
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• 1995

The electrophoretic patterns of plasma membrane surface proteins of normal rat liver cells and rat hepatomas were compared in 10% non-denaturing and 7-15% gradient non-denaturing gel. Chemical carcinogens, 2-Me DAB (2-methyl-4-dimethylaminoazobenzene) and DENA (diethylnitrosamine), were used to induce hepatoma in rats. One protein which disappeared in hepatoma was identified in normal rat liver by non-denaturing gel electrophoresis. Rabbit antisera were raised against this specific protein, and the protein was purified by Sephacryl S-200 column and immunoaffinity chromatography using the purified antibody. The purified protein showed two bands of molecular weights approximately 50 $kD_{\alpha}$ and 52 $kD_{\alpha}$ by SDS-polyacrylamide gel electrophoresis, which reacted specifically with the antibody. However only one band was observed in non-denaturing gel and also in isoelectric focusing with a pI value of 6.6. This study showed the existence of an unique protein on the plasma membrane surface of normal rat liver cells which disappeared in rat hepatomas induced by chemical carcinogens.

• 한국가금학회지
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• 제22권1호
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• pp.43-54
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• 1995

Effects of dietary protein sources and their amino acid compositions on the liver and plasma cholesterol levels in growing Single Comb white Leghorn male chicks were studied. A diet containing isolated soy protein (21% cp) was supplemented with 0.5% DL-methionine and 0.3% L-glycine. and another diet containing casein(21% cp) was supplemented with 1.5% L-arginine HCl, 0.4% DL-methionine. and 1.0% L-glycine. Plasma cholesterol level was markedly lower in groups force-fed the diets containing either soy protein or casein supplemented with amino acids compared to those found in birds fed corresponding diets without amino acids supplementation. The cholesterol lowering effect of the casein diet. when balanced with various supplemental amino acids appeared to be due to arginine instead of methionine or glycine. It is likely that amino acid balance rather than the composition of a specific amino acid is one of the major factors determining the effect of dietary protein sources on the blood cholesterol levels in chicks.

• 한국식품영양과학회지
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• 제5권1호
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• pp.1-9
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• 1976

The variations of growth gain and the composition of free amino acid levels in plasma and erythrocytes of young rats(wistar strain male) were determined by microbioassay method, feeding diets of rice group and 7% casein group as a control for three weeks. The results were as follows; 1. The growth gain of control diet group was higher than the rice diet group. 2. The contents of free tryptophan, lysine, and threonine levels in plasma and erythrocytes on rats of 7% casein group were higher than the rice group. 3. In the 7% casein diet group and the rice group, these free amino acids were included more in erythrocytes than in plasma. 4. Therefore, generally feeding by high protein score diet was included more Try, Lys, Thr in plasma and erythrocytes than feeding by low protein score diet. So the high and low of protein score was assumed by the contents of Try, Lys, Thr in plasma and erythrocytes on rats.