High-protein Nutrition Research Articles

Uji Fitokimia Dan Toksisitas Ekstrak Kasar Gastropoda (Telescopium telescopium) Terhadap Larva Artemia salina

Gastropod is one of the marine organisms that can be used as a source of natural bioactive compounds, one of which is Telescopium telescopium. T. telescopium until now it has not been yet exploited optimally, some people still use it as feed ingredients that contain high protein nutrition, however it must be supported by scientific information about the efficacy and side effects. This research aims at determining the secondary metabolite by crude extract T. telescopium, and the lethal toxicity value (LC50-24 hours). The research consisted of two steps, namely the phytochemical and toxicity test. The method used exploratif and experimental laboratory with a complete randomized design, which consited of five concentration treatments namely 25.12, 63.1, 158.5, 398.15, and 1000 ppm with three replications. Each treatment used 10 Artemia salina larvae, and observations were made during 24 hours of Artemia salina larvae mortality. LC50 was determined by probit analysis using the EPA Probit Analysis Program Version 1.5 Finney. The results of the phytochemical test showed that crude extract T. telescopium contain alkaloid compounds, steroids, flavonoids. The results BSLT (Brine Shrimp Lethality Test) of crude extract T. telescopium LC50-24 hours showed that the crude extract clorofom (229.562 ppm), crude extract ethyl acetate (244.906 ppm), and crude extract methanol (197.242 ppm). LC50-24 hours < 1000 ppm showed that the crude extract Telescopium telescopium potent antitumor compounds.

Hardening of High‐Protein Nutrition Bars and Sugar/Polyol–Protein Phase Separation

Use of hydrolyzed proteins is known to delay hardening of high-protein nutrition bars. Bars were formulated using ratios of 0%, 25%, 50%, 75%, or 100% partially hydrolyzed whey protein isolate (HWPI) to nonhydrolyzed whey protein isolate (WPI) in one experiment, and either WPI or HWPI combined with high-fructose corn syrup (HFCS) or sorbitol syrup (SS) in a 2nd experiment along with vegetable shortening such that initial a(w) was 0.59 for HWPI bars and 0.64 for WPI bars. After mixing, the dough was extruded into bars and stored at 32 degrees C for accelerated shelf-life testing. Hardness, color, and microstructure were measured during 42 d of storage. Bars initially had similar hardness of approximately 3.4 N that increased during storage. Bars with HWPI were softest with hardness at 37 d of 10 to 15 N compared to almost 100 N for bars with WPI. Water activity increased for WPI bars to 0.69 by 34 d. Bars became darker during storage depending on amount of Maillard browning reactants, that is, HWPI/HFCS bars >> HWPI/SS > WPI/HFCS bars > WPI/SS bars. Bar microstructure at day 2 showed protein and fat dispersed in particulate form throughout the carbohydrate syrup within the bar matrix. During storage, a single nonlipid phase developed in HWPI bars while in WPI bars a phase separation occurred between protein and carbohydrate. We propose that such phase separation initiates bar hardening and promotes subsequent protein aggregation. Successful formulation of HPN bars depends on cosolvent properties of the polyol/sugar toward the proteins and their preferential exclusion from the solvation layer surrounding the proteins. High-protein nutrition bars can be formulated so they remain soft during storage by selecting proteins and sugars that are compatible with each other. Otherwise, the protein and sugar will separate from each other which can then lead to hardening.

Evaluation of the possible transmission of BSE and scrapie to gilthead sea bream (Sparus aurata).

In transmissible spongiform encephalopathies (TSEs), a group of fatal neurodegenerative disorders affecting many species, the key event in disease pathogenesis is the accumulation of an abnormal conformational isoform (PrPSc) of the host-encoded cellular prion protein (PrPC). While the precise mechanism of the PrPC to PrPSc conversion is not understood, it is clear that host PrPC expression is a prerequisite for effective infectious prion propagation. Although there have been many studies on TSEs in mammalian species, little is known about TSE pathogenesis in fish. Here we show that while gilthead sea bream (Sparus aurata) orally challenged with brain homogenates prepared either from a BSE infected cow or from scrapie infected sheep developed no clinical prion disease, the brains of TSE-fed fish sampled two years after challenge did show signs of neurodegeneration and accumulation of deposits that reacted positively with antibodies raised against sea bream PrP. The control groups, fed with brains from uninfected animals, showed no such signs. Remarkably, the deposits developed much more rapidly and extensively in fish inoculated with BSE-infected material than in the ones challenged with the scrapie-infected brain homogenate, with numerous deposits being proteinase K-resistant. These plaque-like aggregates exhibited congophilia and birefringence in polarized light, consistent with an amyloid-like component. The neurodegeneration and abnormal deposition in the brains of fish challenged with prion, especially BSE, raises concerns about the potential risk to public health. As fish aquaculture is an economically important industry providing high protein nutrition for humans and other mammalian species, the prospect of farmed fish being contaminated with infectious mammalian PrPSc, or of a prion disease developing in farmed fish is alarming and requires further evaluation.

Histological changes of liver glycogen storage in mice (Mus musculus) caused by high-protein diets.

High Protein diets (HP) have been popular for people who want to lose weight since the 1960s. Even though these diets do not harm healthy people in the short term, there is insufficient data to support their safe use and efficiency over a long period. Because of the fact that the proteins in these diets are mainly from animal sources, it induces a higher intake of total fat, saturated fat and cholesterol. It is proven that high protein diets cause both physical and pathological abnormalities in the body. However, there exist very few studies about the effects of high protein nutrition on liver glycogen storage. For this study 40 Swiss albino mice consisting of two groups were used. The first group was fed with 25% High Protein; the other was fed with standard meal. The two groups were fed with respect to their diets for 30 days. At the end of 15th, 20th, 25th and 30th days 5 from each group were killed with cervical dislocation. The livers were removed after perfusion then fixated. The routine paraffin pursuit was applied before cutting into 5 micrometer sections and staining with H-E, PAS and silver. There were major differences in weight loss between the first and the fifteenth days. Glycogen storage was significantly reduced in HP (15) stained with PAS. Hydropic degeneration and regenerative activity was observed in H-E and silver stained HP group. As a result for the high protein diet group, weight loss at the 15th day and a significant decrement in glycogen storage at the 30th day was observed.

Nutritional counselling: an intervention for HIV‐positive patients

This paper reports an investigation of the effectiveness of nutritional counselling as an intervention to improve health outcomes for HIV-positive patients in Ghana, West Africa. In Ghana, like many developing countries, more patients with HIV and AIDS die because of their poor nutritional status than from the disease itself. With the lack of highly active anti-retroviral therapy for most HIV-infected patients in developing countries, nutritional counselling about high protein diet can be an essential intervention to reduce weight loss and improve weight gain and survival outcomes. We used secondary-analytic data collected in summer 2003. Recorded monthly weights of HIV-positive patients were obtained and analysed for 25 people, whose ages ranged from 21 to 60 years, with a mean of 39.4 years (sd = 10.13). HIV-positive patients responded favourably to nutritional counselling about protein dietary intake as an intervention to improve weight gain. Repeated measures showed a statistically significant weight gain (P = 0.008). In the absence of anti-retroviral therapy, high protein nutrition can be an effective intervention for HIV-positive patients in developing countries. The health and nutritional status of the patients can be improved through nutritious food, allowing them to lead longer and better quality lives.

High-protein nutrition during pregnancy and lactation programs blood pressure, food efficiency, and body weight of the offspring in a sex-dependent manner

Maternal low-protein diet during pregnancy is a risk factor for cardiovascular disease of the offspring in later life. The impact of high-protein diet during pregnancy on the cardiovascular phenotype of the offspring, however, is still unknown. We examined the influence of a high-protein diet during pregnancy and lactation on the renal, hemodynamic, and metabolic phenotype of the F1 generation. Female Wistar rats were either fed a normal protein diet (20% protein: NP) or an isocaloric high-protein diet (40% protein: HP) throughout pregnancy and lactation. At weaning, the offspring were fed with standard diet, and they were allocated according to sex and maternal diet to four groups: normal-protein male (NPm, n = 25), normal-protein female (NPf, n = 19), high-protein male (HPm, n = 24), high-protein female (HPf, n = 29). During the experiment (22 wk), the animals were characterized by repeated measurement of body weight, food intake, blood pressure, glucose tolerance, energy expenditure, and kidney function. At the end of the study period histomorphological analyses of the kidneys and weight measurement of reproductive fat pads were conducted. There were no differences in birth weight between the study groups. No influence of maternal diet on energy expenditure, glucose tolerance, and plasma lipid levels was detected. Blood pressure and glomerulosclerosis were elevated in male offspring only, whereas female offspring were characterized by an increased food efficiency, higher body weight, and increased fat pads. Our study demonstrates that a high-protein diet during pregnancy and lactation in rats programs blood pressure, food efficiency, and body weight of the offspring in a sex-dependent manner.

Influence of exercise and nutrition countermeasures during 60 d of bedrest in women: Soleus single muscle fiber function

Twenty-one women underwent 60 d bedrest (BR, n=7) to examine the effect of a concurrent aerobic (27 sessions) and resistance (19 sessions) exercise (BRE, n=6) or a leucine enriched high protein nutrition (BRN, n=8) countermeasure. Muscle biopsies were obtained before and day 59 of bedrest. Single muscle fibers were studied for diameter (Dia), peak force (Po), normalized peak force (Po/CSA), contractile velocity (Vo) and MHC composition. Only MHC I fibers were included due to low prevalance of other MHC isoforms. Single muscle fiber Dia decreased (P<0.05) 15% in BR (91±3 vs. 77±4 μm), and 14% in BRN (94±3 vs. 81±3 μm). Po decreased (P<0.05) 36% in BR (0.52± 0.04 vs. 0.33±0.03 mN) and 21% in BRN (0.60±0.06 vs. 0.44±0.03 mN). No changes in Po/CSA or Vo were observed in BR, BRN or BRE. For the BRE group, three individuals increased Dia (+5%) and Po (+18%) and three individuals had a decline in Dia (−22%) and Po (−48%). As a result, a non-significant decline in Dia (−10%) and Po (−18%) were observed for the entire BRE group. These data show that individual responses in the BRE group were apparent for the soleus MHC I fibers. A homogeneous decline in the BRN group and the similarity to the BR group indicates that the nutritional countermeasure did not provide a benefit for the MHC I soleus muscle fibers. Sponsors: NASA, ESA, CNES

Influence of exercise or nutrition countermeasures during 60 d of bedrest in women: Thigh and calf muscle volume

Twenty-four women underwent 60 d of bedrest (BR, n=8) to examine the effect of a concurrent aerobic (27 sessions) and resistance (19 sessions) exercise (BRE, n=8) or a leucine enriched high protein nutrition (BRN, n=8) countermeasure. Magnetic resonance imaging was completed before and on days 29 and 57 of bedrest. BR had a −21±1% loss (P<0.05) of thigh muscle volume on day 57. The combination of aerobic and resistance exercise (BRE) was successful in maintaining thigh muscle volume (P>0.05), while nutrition (BRN) exacerbated this loss (−24±2%, P<0.05) compared to BR. BR had a −29±1% loss of calf muscle volume on day 57. The combination of aerobic and resistance exercise (BRE) provided a large but not complete offset of calf muscle volume loss (−8±2%, P<0.05). BRN had a −28±1% loss of calf muscle volume (P<0.05), which was no different than BR (P>0.05). The nutrition countermeasure was not effective in offsetting muscle mass loss during bed rest. The concurrent aerobic and resistance exercise protocol was an effective countermeasure to prevent thigh muscle loss. While the exercise protocol offset 21% of the calf muscle volume loss, modification of this regimen is needed to be completely effective in women. Sponsors: NASA, ESA, CNES

Influence of exercise or nutrition countermeasures during 60 d of bedrest in women: Thigh and calf muscle performance

Twenty-four women underwent 60 d of bedrest (BR, n=8) to examine the effect of concurrent aerobic (27 sessions) and resistance (19 sessions) exercise (BRE, n=8) or a leucine enriched high protein nutrition (BRN, n=8) countermeasure. Muscle performance was assessed before and on day 2 following bedrest. Dynamic (concentric force, CON; eccentric force, ECC; power, PWR; work, WRK) and static (maximal voluntary contraction, MVC) muscle performance was measured using supine squat and calf press on a flywheel ergometer. For the thigh, both BR and BRN experienced a similar decrease (P<0.05) in CON (BR: −21%, BRN: −28%), ECC (BR: −20%, BRN: −26%), PWR (BR: −27%, BRN: −33%), WRK (BR: −19%, BRN: −25%), and MVC (BR: −33%, BRN: −32%). Conversely, BRE maintained (P>0.05) ECC, WRK, and MVC, and increased (P<0.05) CON: +24% and PWR: +23%. For the calf, both BR and BRN experienced a similar decrease (P<0.05) in CON (BR: −31%, BRN: −26%), ECC (BR: −29%, BRN: −26%), PWR (BR: −46%, BRN: −39%), WRK (BR: −40%, BRN: −30%), and MVC (BR: −43%, BRN: −46%). Conversely, BRE maintained (P>0.05) MVC and increased (P<0.05) CON: +32%, ECC: +36%, PWR: +30%, and WRK: +22%. The concurrent exercise countermeasure was effective in preventing the deleterious effects of bedrest on thigh and calf muscle performance, while the nutrition countermeasure resulted in no beneficial effect. Sponsors: NASA, ESA, CNES

Influence of exercise or nutrition countermeasures during 60‐d of bedrest in women: Composite view of myocellular contractile properties

Twenty-four women underwent 60 d of bedrest (BR, n=8) to examine the effect of a concurrent aerobic (27 sessions) and resistance (19 sessions) exercise (BRE, n=8) or a leucine enriched high protein nutrition (BRN, n=8) countermeasure. Muscle biopsies were obtained before and day 59 of bedrest from the vastus lateralis (VL) and soleus (SOL). Single muscle fibers were studied for diameter (Dia), peak force (Po), normalized peak force (Po/CSA), contractile velocity (Vo), and MHC composition. Single fiber data for pure fibers (MHC I, IIa, IIx) and hybrid fibers (MHC I/IIa, IIa/IIx, I/IIa/IIx) were collapsed into a composite value for each variable from each subject's weighted fiber type means pre and post bedrest. This composite value reflects an overall functional profile of the single muscle fibers studied. In this manner, all fiber types and alterations in MHC distribution with the various interventions are represented for a given muscle. VL Dia decreased (P<0.05) 16% in BR and BRN. VL Po decreased (P<0.05) 37% in BR and 34% in BRN. VL Dia and Po were unchanged in BRE. SOL Dia decreased (P<0.05) 11% in BR and 18% in BRN. SOL Po decreased (P<0.05) 23% in BR and 32% in BRN. SOL Dia and Po were unchanged in BRE. No change in Po/CSA and Vo were observed with bedrest in the three groups (VL and SOL). This composite VL and SOL single fiber profile shows that concurrent exercise maintains cellular diameter and peak force. The nutritional countermeasure does not provide a myocellular size or functional benefit. Sponsors: NASA, ESA, CNES

Influence of exercise and nutrition countermeasures during 60 d of bedrest in women: Vastus lateralis single muscle fiber function

Twenty-four women underwent 60 d of bedrest (BR, n=8) to examine the effect of a concurrent aerobic (27 sessions) and resistance (19 sessions) exercise (BRE, n=8) or a leucine enriched high protein nutrition (BRN, n=8) countermeasure. Muscle biopsies were obtained before and day 59 of bedrest. Slow (MHC I) and fast (MHC IIa) muscle fibers were studied for diameter (Dia), peak force (Po), normalized peak force (Po/CSA), contractile velocity (Vo), and MHC composition. BR had a decrease (P<0.05) in MHC I Dia (−13%), Po (−36%), and Po/CSA (−17%). A similar trend was observed in BR MHC IIa fibers for Dia (−15%; P=0.09) and Po (−25%; P=0.14). BRN had a decrease (P<0.05) in MHC I Dia (−18%) and Po (−38%) and MHC IIa Dia (−26%). BRN had a trend for a decrease in MHC IIa Po (−41%; P=0.10). BR and BRN MHC I and IIa Vo was unchanged. BRE MHC I and IIa fiber Dia, Po, Po/CSA, and Vo were unchanged with bedrest. These data show that the MHC I fibers were more affected than the MHC IIa fibers with bedrest. The concurrent exercise-training program preserved MHC I and IIa diameter and contractile function during bedrest. The nutrition countermeasure did not provide any benefit for myofiber diameter or peak tension. Sponsors: NASA, ESA, CNES

Adaptive Biological Trends in the European Upper Palaeolithic: The Case of the Sunghir Remains

Sunghir is one of the most important Upper Palaeolithic sites in the world because of its most Northern location, the extraordinary richness of the artifacts, and the state of human bone preservation. The skeletal finds give evidence for the study both of adult and subadult body builds in the group. For the reconstruction of patterns of postcranial morphology, total measurements of bones and X-ray observations have been used. We have determined the basic structural traits typical for Sunghirians: small corticalisation of adult postcranial skeletons; large volume of the bone marrow cavity relative to the general size; quick tempo of attainment in early ontogenesis of large adult size combined with late synostoses ensuring prolonged linear growth; macroskelia combined with extreme andromorphy in the shoulder belt structure; capacious chest. The above traits can be interpreted in terms of adaptation to such formative factors as low temperature stress, deficit of atmospheric oxygen, high protein nutrition, and mechanical loads.

The effect of high dietary protein levels during late gestation on colostrum yield and lamb survival rate in singleton-bearing ewes

The study was carried out to determine the effect of crude protein (CP) levels in late pregnancy on the subsequent colostrum production and lamb survival rate. A total of 40 singleton-bearing Hampshire Down X Karayaka (F 1) crossbred ewes were allocated to two treatment groups ( n=20 for each group), namely a control (P) and high CP (1.4P) group. The ewes in the P group were fed a protein maintenance level for pregnant ewes (117 g CP and 10.5 MJ metabolizable energy (ME)/kg dry matter (DM)), while ewes in the 1.4P group were fed 1.4 times the protein requirement level for pregnant ewes (165 g CP and 10.5 MJ ME/kg DM). The high crude protein level (1.4P) offered to the ewes did not affect lamb body weight from birth to weaning, however, it increased the live weight changes of ewes (2.5±1.3 kg for P versus 6.4±1.5 kg for 1.4P; P<0.05), lambing difficulty (5% versus 30%; χ 2=4.33; P<0.05) and lamb birth weight (4.3±0.1 kg versus 4.9±0.1 kg; P<0.05). It also decreased the total colostrum yield (1700±165 g versus 1200±147 g; P<0.01) and lamb survival from birth to weaning (100% versus 80%; χ 2=4.44; P<0.05). These results indicate a high level of CP (1.4P) supplementation to singleton-bearing ewes during late gestation to increase lamb birth weight decrease colostrum yield, increase lambing difficulty and reduce lamb survival rate prior to weaning. In conclusion, because of the adverse effect of high dietary protein nutrition during late gestation on colostrum yield and lamb survival rate in singleton-bearing ewes, feeding of protein to pregnant ewes with a view to increase postnatal lamb growth performance and lamb survival rate, should be treated with caution.

Hypocaloric Parenteral Nutrition Support in Elderly Obese Patients

Hypocaloric nutritional support has been successfully used to achieve positive nitrogen balance in obese patients. However, advanced age is associated with changes in substrate metabolism. To evaluate the efficacy of this practice in elderly patients, we retrospectively reviewed 30 obese patients requiring parenteral nutrition support. Total caloric requirements (TCR) were calculated on the basis of the Harris-Benedict equation. Patients were given a minimum of 1.5 g/kg/day protein, 75 per cent of TCR when current body weight was >120 and < or =150 per cent of ideal body weight (IBW), and 60 per cent of TCR if current body weight was >150 per cent of IBW. The patients were divided into two groups: Group I (N = 18) patients were age <60 and Group II (N = 12) patients were > or =60 years of age. Only one of the Group I patients (143.2 +/- 25.7% IBW, received 18.2 +/- 3.7 kcal/kg/day and 1.6 +/- 0.4 g/kg/day protein), but five of the Group II patients (141.3 +/- 14.4% IBW, received 18.3 +/- 2.6 kcal/kg/day and 1.7 +/- 0.3 g/kg/day protein), had negative nitrogen balance (P = 0.025). Apparently, elderly obese patients have limited capacity to mobilize their fat stores as energy sources and may continue to undergo protein catabolism with hypocaloric high-protein nutrition support. Therefore, this form of nutritional support should be used with caution in elderly obese patients.

Evaluation of early enteral feeding in children less than 3 years old with smaller burns (8–25 per cent TBSA)

Early enteral feeding and high protein nutrition have been advocated for burned patients. The safety and efficacy of early high protein nasogastric feeding (NG) have not been evaluated in very young children. The present study evaluated such feeding in children less than 3 years old with smaller burns (8–25 per cent of total body surface area). Children (n = 10) were able to tolerate high protein intake without detrimental effects. The incidences of gastrointestinal complications related to NG feeding were low. The children needed approximately 2 weeks of supplemental NG feeding which provided two-thirds of total energy intake and three-fourths of protein intake. In spite of smaller burns, the mean measured resting metabolic expenditure (REE) was 1.3 × predicted REE. The mean energy intake of 92 per cent of recommended daily allowances (RDA) for energy or 1.7 × predicted REE was able to maintain body weight. The mean protein intake was 4.3 g/kg/day with a non-protein calorie ratio of 114:1. During the first week postburn, plasma concentrations of prealbumin, albumin and transferrin were low. The high protein intake was able to raise these visceral proteins to normal ranges. These results indicate that early NG feeding is safe and efficacious for achieving increased energy intake and improved protein status in very young children.

Hypermetabolism and hypercatabolism in Guillain-Barré syndrome.

We studied 21 patients with Guillain-Barré syndrome who demonstrated multiple nutritional risk factors upon admission to an intensive care unit: ventilator dependence (71.4%), adynamic ileus (23.8%), significant weight loss in the 2 weeks before admission (53.0%), antecedent viral illness with gastrointestinal sequelae (43.0%), cranial nerve deficits impairing oral intake and gastrointestinal motility (60%), and depressed serum transferrin (85.7%). Patients are hypermetabolic and hypercatabolic because of endocrine, infectious, and inflammatory components of the disease. High-energy (40 to 45 nonprotein kcal/kg), high-protein (2.0 to 2.5 g/kg) nutrition support appears to exert a favorable effect on visceral protein repletion, nitrogen balance, and resistance to pulmonary infection. Immediate attainment of positive energy balance in these hypermetabolic patients, ideally assessed by indirect calorimetry and followed by high-energy, high-protein feedings, may promote positive nitrogen balance early and attenuate muscle wasting in Guillain-Barré syndrome.

Effects of dietary protein content on weaning from the ventilator

The effect of enteral nutrition with different protein contents on metabolic and ventilatory variables during weaning from the ventilator was studied in 10 mechanically ventilated patients as indication of the effect of protein on the ventilatory drive. Resting energy expenditure (R.E.E.) was assessed in the post-absorptive state and 2 enteral regimens both with a fat and carbohydrate content 1.25 times R.E.E. but with a moderate (190 mg N/kg/24 h) and high (260 mgN/kg/24 h) protein content were given to the patients in random order. Minute ventilation (V̇ E), CO 2-production (V̇CO 2), O 2-consumption (V̇O 2) and arterial blood-gases were obtained during mechanical ventilation and weaning. Compared with post-absorptive state, both intakes gave significant increases in V̇CO 2 during mechanical ventilation; the V̇CO 2 values were equal for both regimens before the start of the weaning procedures. High protein intake was associated with significantly higher V̇CO 2 during weaning and smaller increases in p aCO 2 from mechanical ventilation to the end of the weaning-period, compared with the moderate protein intake. This result is in agreement with studies in which an infusion of amino-acids in spontaneous breathing healthy volunteers increased ventilatory sensitivity to CO 2. For mechanically ventilated patients high protein nutrition may be beneficial in enhancing weaning from the ventilator.

Management of crush syndrome.

Our experience in treating seven patients with severe crush injury of the lower limbs is described. They were brought to hospital 12 h after rescue and had no treatment until then. All seven developed acute renal failure due to myoglobinuria and dehydration. Five were anuric and three non-oliguric. All developed severe sepsis and two had also acute respiratory failure. No bleeding tendency was observed. They were treated along the following lines: early extensive fasciotomy and removal of dead tissues; early fluid challenge; early peritoneal dialysis and/or hemodialysis; high caloric, high protein nutrition; vigorous antibiotic therapy when infection was evident. There were no deaths in our patients. Our management and results are discussed and compared with those in the literature.

The effect of proteinase inhibitors in rats. 1. Report. Effect of a short-term application on the N balance, the free amino acids in liver and muscles and the biological half-life of the intestinal tissue proteins

Short-term trials with a triazin derivative and a peptide aldehyde were carried out to investigate the in-vivo administration of proteinase inhibitors in rats for improving the N balance of the animals. The results of N balances suggest that the peptide aldehyde may be regarded as a promising substance that may be used to increase the rate of utilization of the absorbed N in the intermediary metabolism. The short-term use of both active compounds did not affect the true N digestibility. The two compounds did not influence the concentration of free amino acids in the liver and muscle tissue under the experimental feeding conditions used. Similarly, tests of the biological half-life of proteins taken from the small and large intestine did not reveal any changes due to the presence of the inhibitors. Animals receiving a protein-free diet exhibited longer half-life periods for proteins from the small and large intestine compared with animals of the other groups. A protein-free nutrition of the animals caused a general increase in the levels of free non-essential amino acids in the liver. This was accompanied by a simultaneous decrease in essential amino acids. The same type of nutrition led to a general decline in the concentration of free amino acids in muscular tissue, particularly of the essential amino acids. High-protein nutrition led especially to an increase in the concentration of branched-chain amino acids in both types of tissues investigated.

Nutrition under Abnormal Environment (Report 5)

Influence of raitio of three calorigenic nutrients as well as protein quality upon growth and metabolism of rats was observed for 11 weeks, exposing half of them to vibration.Raitio of three calorigenic nutrients and protein score fed to five groups were as follows:1. Standard: protein 16% score 79, oil 10%2. High protein-high fat: protein 25% score 90, oil 25%3. High protein-low fat: protein 25% score 90, oil 2%4. Low protein-high fat: protein 8% score 75, oil 25%5. Low protein-low fat: protein 8% score 75, oil 2%Both high protein groups showed more increas in body weight than other groups, particularly high protein-high fat group gave the best growth, and none of abnormal symptoms was seen in their organs and metabolism.On the contrary, both low protein groups showed distinctly less increase in body weight, specially the low protein-hight fat group showed the least, indicating abnormal signs and metabolism.The unfavorable influences from vibration were proved here again to be protected by high protein nutrition.