Dietary protein regulates hepatic constitutive protein anabolism in rats in a dose-dependent manner and independently of energy nutrient composition

We had previously observed that drastic increases in protein consumption greatly modified hepatic protein anabolism in rats, but the confounding effects of other macronutrient changes or a moderate protein increase to generate the same modifications have not yet been established. This study examined the metabolic and hormonal responses of rats subjected to 14-day isoenergetic diets containing normal, intermediate, or high-protein levels (NP: 14% of energy, IP: 33%, HP: 50%) and different carbohydrate (CHO) to fat ratios within each protein level. Fasted or fed rats ( n = 104) were killed after the injection of a flooding dose of 13C-valine. The hepatic protein content increased in line with the dietary protein level ( P < 0.05). The hepatic fractional synthesis rates (FSR) of protein were significantly influenced by both the protein level and the nutritional state (fasted vs. fed) ( P < 0.0001) but not by the CHO level, reaching on average 110%/day, 92%/day, and 83%/day in rats fed the NP, IP, and HP diets, respectively. The FSR of plasma albumin and muscle did not differ between diets, while feeding tended to increase muscle FSR. Proteolysis, especially the proteasome-dependent system, was down-regulated in the fed state in the liver when protein content increased. Insulin decreased with the CHO level in the diet. Our results reveal that excess dietary protein lowers hepatic constitutive, but not exported, protein synthesis rates, independently of the other macronutrients, and related changes in insulin levels. This response was observed at the moderate levels of protein intake (33%) that are plausible in a context of human consumption.

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Effects of variations in dietary protein levels on hair growth and pelt quality in mink (Mustela vison)

Canadian Journal of Animal Science ◽

10.4141/a99-063 ◽

2000 ◽

Vol 80 (4) ◽

pp. 633-642 ◽

Cited By ~ 6

Author(s):

Palle V. Rasmussen ◽

Christian F. Børsting

Keyword(s):

Protein Content ◽

Dietary Protein ◽

Protein Level ◽

Hair Growth ◽

Fibre Length ◽

Hair Follicles ◽

Protein Levels ◽

Low Protein ◽

Pregnancy And Lactation ◽

Hair Fibre

The effect of different and shifting dietary protein levels on hair growth and the resulting pelt quality in mink was studied. Two groups of pastel female mink were fed either 59% (high protein, HP) or 40% (low protein, LP) of metabolisable energy (ME) from protein during pregnancy and lactation. Shortly after weaning, kits from females fed the LP diet were put on a new LP diet (21% protein of ME). Kits from females fed HP were randomly distributed to four experimental groups fed a new HP diet (34% protein of ME) and three of these groups were shifted to diets with 21% protein at different times during June until September. Skin biopsies were taken at 4, 6, 23 and, 29 wk of age. Histological techniques and computer-assisted light microscopy were used to determine the ratio of activity (ROA) of underfur and guard hairs, respectively, defined as the number of growing hairs as a percentage of the total number of hairs. The hair fibre length and thickness were determined by morphometric methods and correlated with fur properties of dried pelts judged by sensory methods. It was documented that 40% of ME from protein during pregnancy and lactation was sufficient for mink kits to express their genetic capacity to produce hair follicles. In males, a reduced protein level from the age of 15 wk or 22 wk until pelting disturbed moulting, indicated by a low ROA of underfur hairs at 23 wk, and consequently reduced the growth and development of the winter coat. A constantly low protein level from conception until the age of 29 wk did not disturb moulting, but led to a reduction of primeness and especially of the underfur length and fibre thickness of the winter coat. A low protein level from the age of 9 wk only reduced the thickness of the underfur fibres. Hair growth, final fur volume, and general quality of the winter coat of males were influenced negatively and to the same degree in all groups fed the LP diet in part of the growth period. The number of underfur hairs per area (hair density) of the winter coat was not influenced by the dietary treatment meaning that the protein content of 21% of ME in the LP diet was high enough for the mink to express its genetic capacity to develop hair follicles. However, this low protein content led to a reduction of hair fibre length and hair fibre thickness of the underfur. Overall, this study demonstrated that hair growth and hair properties in pelts are very dependent on the dietary protein supply in the period from 22 wk of age until pelting, irrespective of the supply in the preceding periods. Key words: Fur properties, hair fibres, nutrition, pelage, protein requirement

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Effect of dietary protein level and salinity on growth, survival, enzymatic activities and amino-acid composition of the white shrimp Litopenaeus vannamei (Boone, 1931) juveniles

Crustaceana ◽

10.1163/15685403-00003390 ◽

2015 ◽

Vol 88 (1) ◽

pp. 82-95 ◽

Cited By ~ 8

Author(s):

Liying Sui ◽

Guannan Ma ◽

Yuangao Deng

Keyword(s):

Amino Acid ◽

Protein Content ◽

Muscle Tissue ◽

Litopenaeus Vannamei ◽

Dietary Protein ◽

Protein Level ◽

White Shrimp ◽

Lower Growth ◽

Protein Levels ◽

Dietary Protein Level

Litopenaeus vannamei (Boone, 1931) postlarvae with average initial body weight of 0.089 g were reared in 75-litre PVC tanks for 40 days at salinities of 30 and 60 g l−1. The shrimps were fed compound feed containing protein levels of 35, 40, 45 and 50%, respectively. Salinity had a remarkable effect on growth and survival of L. vannamei juveniles. Higher survival rate and lower growth were observed at 60 g l−1 salinity. Dietary protein level affected the survival and growth of juveniles at both salinities, increased with dietary protein levels in the range of 35 to 45%, but decreased slightly with 50% dietary protein. Broken line analysis showed that the estimated optimal dietary protein levels at salinities of 30 and 60 g l−1 were 45.93 and 46.74%, respectively. Higher salinity resulted in an increased moisture content, ash and crude protein content in the shrimp muscle tissue. The amino acid contents in the shrimp muscle tissue were generally higher at 60 g l−1 salinity and increased dietary protein level led to higher protein content, except with 50% dietary protein. At salinity 60 g l−1, the soluble protein content and activities of glutamic oxalacetic transferase (GOT) and glutamic pyruvic transaminase (GPT) in shrimp muscle tissue were higher, while catalase (CAT) activities were lower. Farming of L. vannamei at a marginal culture salinity (60 g l−1) is feasible though the shrimps were likely exposed to stressful conditions. Reduced growth rate at higher salinity may be attributed to the higher total ammonium (TAN) concentration in the culture medium and extra energy consumption for osmoregulation at hypersaline conditions.

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Dietary supplementation of organic selenium to improve growth performance and protein utilization in African catfish fed with different protein level diets

Jurnal Akuakultur Indonesia ◽

10.19027/jai.20.2.130-138 ◽

2021 ◽

Vol 20 (2) ◽

pp. 130-138

Author(s):

Giri Maruto Darmawangsa ◽

Muhammad Agus Suprayudi ◽

Nurbambang Priyo Utomo ◽

Julie Ekasari

Keyword(s):

Growth Performance ◽

Dietary Protein ◽

Protein Level ◽

Dietary Supplementation ◽

High Protein ◽

Utilization Efficiency ◽

African Catfish ◽

Protein Utilization ◽

Organic Selenium ◽

Protein Levels

This study aimed to evaluate the effect of organic selenium supplementation on diet with different protein levels on the growth performance and protein utilization of African catfish juvenile. A randomized 2×3 factorial design with two dietary protein levels (27% and 32%) and three dietary selenium (Se) supplementation levels (0 mg/kg, 3 mg/kg, and 6 mg/kg diet) in triplicates were applied in the study. African catfish juvenile with an initial average body weight and body length of 27.00 ± 0.14 g and 15.0 ± 0.5 cm, respectively, was reared in 18 units of aquarium (141 L) at a density of 142 fish/m3 for a rearing period of 40 days. Increasing organic Se supplementation level up to 6 mg/kg at high protein feed resulted in higher fish growth and final biomass, lower FCR, and higher protein utilization efficiency than those of other treatments. Furthermore, supplementation of organic Se also resulted in lower lipid and higher Se concentrations in the fish body as well as higher blood protein level compared to those of the control. In conclusion, the result of this study suggested that dietary supplementation of organic Se up to 6 mg/kg could enhance the growth and protein utilization in African catfish fed with both low and high protein diet. Keywords: African catfish, growth, dietary protein, protein utilization, organic selenium. ABSTRAK Penelitian ini bertujuan mengevaluasi pengaruh suplementasi selenium organik pada pakan dengan kadar protein yang berbeda terhadap kinerja pertumbuhan dan pemanfaatan protein pakan ikan lele Clarias gariepenus. Penelitian didesain menggunakan rancangan acak lengkap faktorial 2×3 dengan dua tingkat protein pakan (27% dan 32%) dan tiga tingkat suplementasi selenium (Se) pakan (0 mg/kg, 3 mg/kg, dan 6 mg/kg diet) sebanyak tiga ulangan. Ikan lele yang digunakan memiliki bobot awal rata-rata dan panjang tubuh 27 ± 0.14 g dan 15.0 ± 0.5 cm, dipelihara dalam 18 unit akuarium (141 L) dengan kepadatan 142 ekor/m3 selama 40 hari pemeliharaan. Peningkatan suplementasi Se organik hingga 6 mg/kg pada ikan yang diberi pakan protein tinggi menghasilkan kinerja pertumbuhan ikan dan biomassa akhir yang lebih tinggi, FCR yang lebih rendah, dan efisiensi pemanfaatan protein pakan yang lebih tinggi daripada perlakuan lain. Selain itu, suplementasi Se organik juga menghasilkan kadar lemak yang lebih rendah dan konsentrasi Se tubuh yang lebih tinggi serta kadar protein darah yang lebih tinggi. Kesimpulan dari penelitian ini yaitu suplementasi Se organik pada pakan hingga 6 mg/kg dapat meningkatkan kinerja pertumbuhan dan pemanfaatan protein pakan pada ikan lele yang diberi pakan dengan kadar protein rendah dan tinggi. Kata kunci: ikan lele, pertumbuhan, protein pakan, pemanfaatan protein, selenium organik.

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OPTIMUM PROTEIN AND ENERGY LEVELS FOR FINISHING BROILER CHICKENS IN A TROPICAL ENVIRONMENT

Nigerian Journal of Animal Production ◽

10.51791/njap.v4i1.2240 ◽

2021 ◽

Vol 4 (1) ◽

pp. 239-253

Author(s):

M. J. Olomu

Keyword(s):

Dietary Protein ◽

Protein Level ◽

Feed Efficiency ◽

Broiler Chickens ◽

Energy Levels ◽

Tropical Environment ◽

Tropical Country ◽

Protein Levels ◽

Groundnut Meal ◽

Dietary Treatments

Three experiments were conducted to determine the optimum protein and energy levels for finishing broiler chickens in a tropical environment. Dietary protein levels (20, 23 and 26 percent) and energy levels (2800, 3000 and 3200 Kcal/kg diet) tested had no significant effects on performance of finishing chickens fed fishmeal-containing rations. Rations based on cereals and groundnut meal, without fishmeal, did not support maximum liveweight gain and feed efficiency at dietary protein levels below 26 percent. Dietary treatments had no significant effects on carcass dressing percentages. Based on the present results, a protein level of 20 percent(for fishmeal containing rations) and 23 or 26 percent (for rations based on groundnut meal without fishmeal) and energy levels of 2800 to 3000 Kcal/Kg diet are tentatively recommended for finishing broiler chickens raised in a tropical country like Nigeria.

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The effects of dietary protein content on growth and maturation in deer mice

Canadian Journal of Zoology ◽

10.1139/z99-156 ◽

1999 ◽

Vol 77 (11) ◽

pp. 1822-1828 ◽

Cited By ~ 8

Author(s):

Andrew G McAdam ◽

John S Millar

Keyword(s):

Protein Content ◽

Dietary Protein ◽

Maternal Diet ◽

Natural Populations ◽

Female Offspring ◽

Deer Mice ◽

Nestling Growth ◽

Protein Levels ◽

In Captivity ◽

Isocaloric Diets

Growth and female maturation appear to be limited by the availability of dietary protein in natural populations of deer mice (Peromyscus maniculatus borealis) in the Kananaskis Valley, Alberta. We examined the effects of dietary protein content on nestling growth rates and sexual maturation of female deer mice in two laboratory experiments. In the first, mice whose mothers were fed a low-protein mixture of sunflower seeds and oats (14% protein) exhibited slow growth prior to weaning and those fed high-protein cat food (30% protein) postweaning showed compensatory growth. Preweaning but not postweaning diet quality affected the proportion of females who were sexually mature at 42 days of age. Therefore, while deficient nestling growth can be compensated for, the effects of a low-quality maternal diet during lactation may have lasting effects on the maturation of female offspring. In the second experiment, mice raised on isocaloric diets of 14, 20, and 30% protein did not differ in growth as nestlings or juveniles. Differences among the three diets in the proportion of mature females at 42 days did not correspond to dietary protein levels as predicted. Dietary protein content from 14 to 30% appear to be sufficient for juvenile mice raised in captivity.

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Abstract 492: Arachidonic Acid Induces Activation of Platelet PF4 and Par-1 mRNA, Which Is Attenuated by Aspirin

Arteriosclerosis Thrombosis and Vascular Biology ◽

10.1161/atvb.32.suppl_1.a492 ◽

2012 ◽

Vol 32 (suppl_1) ◽

Author(s):

Liang Hu ◽

Michael A Nardi ◽

Michael Merolla ◽

Yajaira Suarez ◽

Jeffrey Berger

Keyword(s):

Arachidonic Acid ◽

Platelet Activation ◽

Mrna Levels ◽

Dependent Manner ◽

Thiazole Orange ◽

Platelet Activity ◽

Protein Levels ◽

Reticulated Platelets ◽

Mrna And Protein Expression ◽

Dose Dependent

Arachidonic acid (AA) is converted to thromboxane A2 via the cyclooxygenase pathway; however its exact mechanism of platelet activation is uncertain. Inhibition of this pathway via aspirin highlights the importance of this pathway in decreasing thrombotic events. In the present study, we investigate the effect of AA on platelet activity indicators (leukocyte- and monocyte-platelet aggregation [LPA, MPA] and reticulated platelets [RP]), as well as the expression (mRNA and protein) of platelet markers PF4 and Par-1, previously well established platelet transcripts with quantitative determinations. To this end, whole blood was incubated with AA (150mM) for 30 min at room temperature in the absence or presence of aspirin (1mM) prior to addition of antibodies for platelet activity indicators, and isolating platelets for mRNA and protein expression. LPA and MPA were significantly increased after AA stimulation in a dose dependent manner, and were inhibited by aspirin treatment. AA significantly increased PF4 and Par-1 protein level as determined by flow cytometry and western blot assays. Pretreatment with aspirin also attenuated this increase in protein levels. Surprisingly, AA stimulation significantly increased thiazole orange staining (a measure of nucleic acids), another marker of increased platelet activity. Importantly, these results suggest that AA-mediated platelet activation produced an overall increase in platelet total RNA content. To confirm these findings, we analyzed the mRNA expression of PF4 and Par-1 by quantitative real time PCR from platelets treated with AA. Interestingly, AA significantly up-regulated the platelet mRNA transcripts of PF4 and Par-1 by 40% to 60%, and pretreatment with aspirin completely attenuated this effect supporting the specificity of the AA effect on platelet RNA. Altogether, these data suggest that platelet mRNA is affected by AA stimulation, which is attenuated by pretreatment with aspirin. However, the mechanisms responsible for the increased mRNA levels and expression of PF4 and Par-1 (processing of pre-RNA to mRNA) require further investigation. Importantly, our findings provide novel insight regarding platelet activation and a better understanding of mediators in the processes of thrombosis and hemostasis.

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THE RELATION OF DIETARY PROTEIN LEVEL TO LIVER ENZYME ACTIVITIES IN COLD-EXPOSED RATS

Canadian Journal of Biochemistry and Physiology ◽

10.1139/y63-213 ◽

1963 ◽

Vol 41 (1) ◽

pp. 1871-1877

Author(s):

John R. Beaton

Keyword(s):

Cold Exposure ◽

Dietary Protein ◽

Protein Level ◽

Liver Enzymes ◽

Albino Rats ◽

Protein Levels ◽

Dietary Protein Level ◽

Phosphate Activated Glutaminase ◽

Relationship Of ◽

Environmental Temperatures

Male, albino rats were fed diets containing 5%, 20%, and 40% casein by weight for 7 days at environmental temperatures of 22 °C and 2–3 °C. In one experiment, food was provided ad libitum; in a second experiment, all groups were provided with equal amounts of food. At 22 °C, the activities in liver of alanine-glutamic transaminase, phosphate-activated glutaminase, and arginase increased with increasing dietary protein level. At 2–3 °C, activities of the last two enzymes increased with increasing dietary protein level from 5% to 20% but not from 20% to 40% whereas transaminase activities increased throughout the dietary protein range 5% to 40%. No relationship of glucose-6-phosphatase activity to dietary protein level was evident at either environmental temperature. Cold exposure per se increased the activities of alanine-glutamic transaminase and glucose-6-phosphatase in all dietary protein groups but increased the activities of arginase and phosphate-activated glutaminase only in rats fed the 5% and 20% protein diets. It is postulated that increased activities of these liver enzymes during cold exposure result from augmented catabolism of substrates to meet increased energy requirements. As previously observed with respect to other metabolic alterations, it is apparent that cold exposure modifies the response of liver enzymes to changing dietary protein levels.

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Effects of Dietary Protein Levels on Bamei Pig Intestinal Colony Compositional Traits

BioMed Research International ◽

10.1155/2020/2610431 ◽

2020 ◽

Vol 2020 ◽

pp. 1-9

Author(s):

Dong Wang ◽

Guoshun Chen ◽

Lili Song ◽

Mingjie Chai ◽

Yongfeng Wang ◽

...

Keyword(s):

Dietary Protein ◽

Protein Level ◽

Crude Protein ◽

Microbial Flora ◽

Protein Levels ◽

Low Protein ◽

Dietary Crude Protein ◽

Protein Diets ◽

Crude Protein Level ◽

Microbial Diversities

Diets containing different crude protein levels (16%, 14%, and 12%) were created to feed Bamei pigs in order to study the effect of these compositions on intestinal colonies. Therefore, 27 healthy Bamei pigs of similar weight ( 20.99 kg ± 0.16 kg ) were selected and randomly divided into three groups for microbial diversity analysis. The results of this study show that microbial diversities and abundances in Bamei pig jejunum and caecum samples after feeding with different dietary protein levels were significantly different. Dietary crude protein level exerted no significant effect on the Shannon index for cecum microbes in these pigs, while Simpson, ACE, and Chao1 indices for group I were all significantly higher than those of either the control group or group II ( P < 0.05 ). Indeed, data show that microbial diversities and abundances in the 14% protein level group were higher than those in either the 16% or 12% groups. Dominant bacteria present in jejunum and cecum samples given low-protein diets were members of the phyla Firmicutes and Bacteroidetes. Data show that as dietary crude protein level decreases, representatives of the microbial flora genus Lactobacillus in jejunum and cecum samples gradually increases. Values for the KEGG functional prediction of microbial flora at different dietary protein levels also show that genes of jejunum and cecum microorganisms were mainly enriched in the “metabolism” pathway and indicate that low protein diets increase intestinal metabolic activity. Therefore, we recommend that Bamei pig dietary protein levels are reduced 2% from their existing level of 16% crude protein. We also suggest that essential synthetic amino acids (AA) are added to optimize this ideal protein model as this will increase intestinal flora diversity in these pigs and enhance health. These changes will have a positive effect in promoting the healthy growth of Bamei pigs.

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Natural Antioxidant Betanin Protects Rats from Paraquat-Induced Acute Lung Injury Interstitial Pneumonia

BioMed Research International ◽

10.1155/2015/608174 ◽

2015 ◽

Vol 2015 ◽

pp. 1-9 ◽

Cited By ~ 15

Author(s):

Junyan Han ◽

Deshun Ma ◽

Miao Zhang ◽

Xuelian Yang ◽

Dehong Tan

Keyword(s):

Body Weight ◽

Acute Lung Injury ◽

Lung Injury ◽

Weight Ratio ◽

Lavage Fluid ◽

Dependent Manner ◽

Sod Activity ◽

Protein Levels ◽

Injury Characteristic ◽

Dose Dependent

The effect of betanin on a rat paraquat-induced acute lung injury (ALI) model was investigated. Paraquat was injected intraperitoneally at a single dose of 20 mg/kg body weight, and betanin (25 and 100 mg/kg/d) was orally administered 3 days before and 2 days after paraquat administration. Rats were sacrificed 24 hours after the last betanin dosage, and lung tissue and bronchoalveolar lavage fluid (BALF) were collected. In rats treated only with paraquat, extensive lung injury characteristic of ALI was observed, including histological changes, elevation of lung : body weight ratio, increased lung permeability, increased lung neutrophilia infiltration, increased malondialdehyde (MDA) and myeloperoxidase (MPO) activity, reduced superoxide dismutase (SOD) activity, reduced claudin-4 and zonula occluden-1 protein levels, increased BALF interleukin (IL-1) and tumor necrosis factor (TNF)-αlevels, reduced BALF IL-10 levels, and increased lung nuclear factor kappa (NF-κB) activity. In rats treated with betanin, paraquat-induced ALI was attenuated in a dose-dependent manner. In conclusion, our results indicate that betanin attenuates paraquat-induced ALI possibly via antioxidant and anti-inflammatory mechanisms. Thus, the potential for using betanin as an auxilliary therapy for ALI should be explored further.

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Performance of the African giant rat (Cricetomys gambianus Waterhouse) on commercial rations and varying dietary protein levels

Laboratory Animals ◽

10.1258/002367778780953224 ◽

1978 ◽

Vol 12 (2) ◽

pp. 109-112 ◽

Cited By ~ 8

Author(s):

S. S. Ajayi ◽

O. O. Tewe

Keyword(s):

Growth Performance ◽

Dietary Protein ◽

Protein Level ◽

Efficiency Ratio ◽

Experimental Diet ◽

Protein Levels ◽

Dietary Protein Level ◽

Food Efficiency Ratio ◽

Cricetomys Gambianus ◽

African Giant Rat

The growth performance of 24 weanling giant rats was studied in 2 experiments of 30 weeks duration with commercial livestock rations and graded levels of protein. Daily average liveweight gain was 5·1-7·3 g, food consumption 26·9-36·3 g on 6 diets. Food intake, growth rate and food efficiency ratio were very similar using the different commercial diets. Growth performance improved as the dietary protein level was raised from 10 to 13%, but a further increase to 16% did not result in greater growth. The commercial pig ration and the experimental diet containing 13% dietary protein level were found to give satisfactory growth, and are recommended for studies with these animals.

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