The Influence of Particle Size and Protein Content in Particle-Filled Myofibrillar Protein Gels

The mechanical properties of glass and wax particle-filled myofibrillar protein gels were characterized based on filler size and surface effects. Increases in elastic moduli were explained using established models describing particle-filled networks.

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Resistance exercise and growth hormone as countermeasures for skeletal muscle atrophy in hindlimb-suspended rats

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1994.267.2.r365 ◽

1994 ◽

Vol 267 (2) ◽

pp. R365-R371 ◽

Cited By ~ 10

Author(s):

J. K. Linderman ◽

K. L. Gosselink ◽

F. W. Booth ◽

V. R. Mukku ◽

R. E. Grindeland

Keyword(s):

Skeletal Muscle ◽

Growth Hormone ◽

Resistance Exercise ◽

Protein Content ◽

Muscle Atrophy ◽

Myofibrillar Protein ◽

Hindlimb Suspension ◽

Skeletal Muscle Atrophy ◽

Plantar Flexor ◽

Fast Twitch

Unweighting of rat hindlimb muscles results in skeletal muscle atrophy, decreased protein synthesis, and reduced growth hormone (GH) secretion. Resistance exercise (ladder climbing) and GH treatment partially attenuate skeletal muscle atrophy in hypophysectomized hindlimb-suspended rats. It was hypothesized that a combination of multiple bouts of daily resistance exercise and GH (1 mg.kg-1.day-1) would prevent skeletal muscle atrophy in growing nonhypophysectomized hindlimb-suspended rats. Hindlimb suspension decreased the absolute (mg/pair) and relative (mg/100 g body wt) weights of the soleus, a slow-twitch plantar flexor, by 30 and 21%, respectively, and the absolute and relative weights of the gastrocnemius, a predominantly fast-twitch plantar flexor, by 20 and 11%, respectively (P < 0.05). Exercise did not increase soleus mass but attenuated loss of relative wet weight in the gastrocnemius muscles of hindlimb-suspended rats (P < 0.05). Hindlimb suspension decreased gastrocnemius myofibrillar protein content and synthesis (mg/day) by 26 and 64%, respectively (P < 0.05). The combination of exercise and GH attenuated loss of gastrocnemius myofibrillar protein content and synthesis by 70 and 23%, respectively (P < 0.05). Results of the present investigation indicate that a combination of GH and resistance exercise attenuates atrophy of unweighted fast-twitch skeletal muscles.

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Effects of Water Particles in the Jinjiang River Estuary on the Physiological and Biochemical Characteristics of Microcystit Flos-Aquae

10.21203/rs.3.rs-557128/v1 ◽

2021 ◽

Author(s):

Yiting Nan ◽

Peiyong Guo ◽

Hui Xing ◽

Sijia Chen ◽

Bo Hu ◽

...

Keyword(s):

Particle Size ◽

Particulate Matter ◽

Protein Content ◽

Suspended Particulate Matter ◽

Soluble Protein ◽

Suspended Particles ◽

Dose Effect ◽

Soluble Protein Content ◽

Sod Activity ◽

Suspended Particulate

Abstract The effects of different concentrations (100,150,200,250 mg/L) and different particle sizes (0–75µm, 75–120µm, 120–150µm, 150–500µm) on soluble protein content, SOD and CAT activity, MDA content, chlorophyll a content and photosynthetic parameters of Microcystis flos-aquae were studied, the mechanism of the effect of suspended particulate matter on the physiology and biochemistry of Microcystis flos-aquae was discussed. The results showed that the soluble protein content of Microcystis flos-aquae did not change obviously after being stressed by suspended particles of different concentration/diameter. The SOD activity of Microcystis flos-aquae increased at first and then decreased with the increase of the concentration of suspended particulate matter. The SOD activity of Microcystis flos-aquae reached 28.03 U/mL when the concentration of suspended particulate matter was 100 mg/L. The CAT activity of Microcystis flos-aquae increased with the increase of the concentration of suspended particles, and reached the maximum value of 12.45 U/mgprot in the concentration group of 250 mg/L, showing a certain dose-effect. The effect of small particle size on SOD, CAT and MDA of Microcystis flos-aquae was more significant than that of large particle size. The larger the concentration and the smaller the particle size, the stronger the attenuation of light and the lower the content of chlorophyll a. Both Fv/Fm and Fv/F0 of Microcystis flos-aquae increased at first and then decreased under different concentration/size of suspended particles. The relative electron transfer rate gradually returned to the normal level with the passage of time. There was no significant difference in α value between treatment group and control group, ETRmax and Ik decreased.

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Myofibrillar Protein Abundance and Anabolic Signaling in Myotubes Depleted of E1 Alpha Subunit of Branched-Chain Ketoacid Dehydrogenase Complex

Current Developments in Nutrition ◽

10.1093/cdn/nzaa049_035 ◽

2020 ◽

Vol 4 (Supplement_2) ◽

pp. 642-642

Author(s):

Glory Madu ◽

Olasunkanmi Adegoke

Keyword(s):

Skeletal Muscle ◽

Amino Acids ◽

Protein Content ◽

Muscle Protein ◽

Essential Amino Acids ◽

Myofibrillar Protein ◽

L6 Myotubes ◽

Branched Chain ◽

Ketoacid Dehydrogenase

Abstract Objectives Branched-chain amino acids (BCAAs) are essential amino acids that are crucial for skeletal muscle anabolism. Thus, alterations in their levels are associated with muscle atrophic diseases such as cancer, chronic inflammatory and neurological disorders. Others have linked impairments in BCAA metabolism to the development of insulin resistance and its sequelae. Compared to the effects of theses amino acids, much less is known on how impairment in BCAA catabolism affects skeletal muscle. BCAA catabolism starts with the reversible transamination by the mitochondrial enzyme branched-chain aminotransferase 2 (BCAT2). This is followed by the irreversible carboxylation, catalyzed by branched-chain ketoacid dehydrogenase (BCKD) complex. We have shown that BCAT2 and BCKD are essential for the differentiation of skeletal myoblasts into myotubes. Here, we investigated the effect of depletion of BCAT2 or of E1a subunit of BCKD in differentiated myotubes. Methods On day 4 of differentiation, L6 myotubes were transfected with the following siRNA oligonucleotides: scrambled (control), BCAT2, or E1a subunit of BCKD. Results Forty-eight hours after transfection, compared to control or BCAT2 siRNA group, we observed improved myotube structure in BCKD-depleted cells. BCKD depletion augmented myofibrillar protein levels: myosin heavy chain (MHC, 2-fold) and tropomyosin (4-fold), P < 0.05, n = 3. To further analyze the increase in myofibrillar protein content, we examined signaling through mTORC1 (mechanistic target of rapamycin complex 1), a vital complex necessary for skeletal muscle anabolism. BCKD depletion increased the phosphorylation of mTORC1 upstream activator AKT (52%, P < 0.05, n = 3), and of mTORC1 downstream substrates by 25%-86%, consistent with the increase in myofibrillar proteins. Finally, in myotubes treated with the catabolic cytokine (tumor necrosis factor-a), BCKD depletion tended to increase the abundance of tropomyosin (a myofibrillar protein). Conclusions We showed that depletion of BCKD enhanced myofibrillar protein content and anabolic signaling. If these data are confirmed in vivo, development of dietary and other interventions that target BCKD abundance or functions may promote muscle protein anabolism in individuals with muscle wasting conditions. Funding Sources MHRC, NSERC York U.

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Influence of the Collection Season on Production, Size, and Chemical Composition of Bee Pollen Produced by Apis Mellifera L.

Journal of Apicultural Science ◽

10.2478/jas-2014-0017 ◽

2014 ◽

Vol 58 (2) ◽

pp. 5-10 ◽

Cited By ~ 2

Author(s):

Adriana F. Negrão ◽

Lidia M. R. C. Barreto ◽

Ricardo O. Orsi

Keyword(s):

Particle Size ◽

Apis Mellifera ◽

Chemical Composition ◽

Protein Content ◽

Nutritional Quality ◽

Particle Sizes ◽

Bee Pollen ◽

Pollen Loads ◽

Food Scarcity ◽

Collection Period

Abstract The aim of our study was to investigate how the collection period affects and influences the production, chemical composition, and size of bee pollen loads (0.5, 1.0, 2.0, greater than 2.0 mm). The results showed there was a predominance of pollen loads with a diameter greater than 2.0 mm in all the production seasons. For all the seasons, there were no differences in protein content between the particle sizes. But when comparing 0.5 mm during the different periods, there were significant differences; the highest value was found during the winter (24.39 ± 3.7%). As far as lipids and crude fiber are concerned, we obtained differences between the same granulometry sizes for the spring and summer seasons. As for ashes, the results showed differences between different particle sizes for the summer and autumn seasons. Our results have shown that regardless of pollen particle size, its quality was not altered, suggesting that smaller loads can be commercially used by containing nutritional quality or else be used by beekeepers as a supplement during periods of food scarcity.

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Effect of preheating on the gel characteristics of pork myofibrillar protein gels with red bean protein and 7S globulin

Meat Science ◽

10.1016/j.meatsci.2013.07.080 ◽

2014 ◽

Vol 96 (1) ◽

pp. 460

Author(s):

H.S. Jang⁎ ◽

K.B. Chin

Keyword(s):

Myofibrillar Protein ◽

Protein Gels ◽

7S Globulin ◽

Red Bean ◽

Bean Protein

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FORMATION OF BARLEY HARVEST DEPENDING ON THE NUTRITION BACKGROUND AND THE USE OF HERBICIDES

Vestnik of Kazan state agrarin university ◽

10.12737/17620 ◽

2015 ◽

Vol 10 (4) ◽

pp. 65-69

Author(s):

Митрофанов ◽

Eduard Mitrofanov ◽

Коршунов ◽

Aleksandr Korshunov ◽

Владимиров ◽

...

Keyword(s):

Particle Size ◽

Particle Size Distribution ◽

Protein Content ◽

Forest Soil ◽

Field Experiments ◽

Gray Forest Soil ◽

Spring Barley ◽

Maximum Yield ◽

Fertilizer Application ◽

Mineral Fertilizers

The effectiveness of herbicides in spring barley crops on different nutrition backgrounds was studied in field experiments on dark gray forest soil of medium loamy particle size distribution in the conditions of Volga-Vyatka region. It is revealed that on both backgrounds of fertilizer application the barley formed a maximum yield, when applying the herbicide Bomba. When using this herbicide in making mineral fertilizers N54P54K54 the productivity was 2.71 tons per hectare and a dose N70P70K70 – it was 2.83 tons per hectare. On average for three years, the maximum (11.35%) protein content was appeared in the preparation by Sekator turbo herbicide on the background of fertilizer application of N70P70K70.

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