Protein synthesis and degradation in flight muscles of adult crickets (Gryllus bimaculatus)

1995 ◽  
Vol 198 (5) ◽  
pp. 1071-1077 ◽  
Author(s):  
T Gomi ◽  
T Okuda ◽  
S Tanaka
Keyword(s):  
Protein Synthesis ◽  
Protein Content ◽  
Total Protein ◽  
Muscle Protein ◽  
Polyacrylamide Gel Electrophoresis ◽  
Adult Life ◽  
Total Protein Content ◽  
Gryllus Bimaculatus ◽  
Flight Muscles

The development and degeneration of the flight muscles in adult crickets, Gryllus bimaculatus, were studied (1) by determination of the total protein content, (2) by SDS one-dimensional polyacrylamide gel electrophoresis (SDS­PAGE) of muscle protein and (3) by in vitro culturing of the muscle. The total protein content of the dorso-longitudinal muscle (DLM) and metathoracic dorso-ventral muscle (DVM) increased during the early days of adult life in both sexes. This high protein content was maintained for at least a further 10 days in some individuals, while in others it declined to a low level. Mesothoracic DVMs in males also showed an increase in protein content after adult emergence but did not undergo histolysis, whereas those in females showed no significant temporal change in protein content. Removal of hind wings or artificial de-alation was found to be useful in inducing degeneration of DLMs and metathoracic DVMs. This treatment also stimulated ovarian development in females. An analysis by SDS­PAGE provided no evidence for new protein synthesis prior to or during flight muscle degeneration. A high rate of [3H]- or [35S]methionine incorporation was observed in DLMs taken from newly emerged adults, but, in intact crickets, the rate declined rapidly during the first 3 days of adult life, a pattern consistent with that obtained from the measurement of total protein content. Compared with DLMs removed from intact crickets, DLMs taken from de-alated crickets showed reduced rates of protein synthesis during in vitro culturing. This, together with the onset of protein degradation, appears to cause the rapid decrease in total protein content of the muscle in de-alated crickets.

Sequential changes in in vivo muscle and liver protein synthesis and plasma and tissue glutamine levels in sepsis in the rat

2001 ◽  
Vol 101 (3) ◽  
pp. 295-304 ◽  
Author(s):  
Michael J. O'LEARY ◽  
Colin N. FERGUSON ◽  
Michael J. RENNIE ◽  
Charles J. HINDS ◽  
John H. COAKLEY ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Protein Content ◽  
Total Protein ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Total Protein Content ◽  
Sham Operation ◽  
Liver Protein ◽  
Male Wistar Rats

We have investigated sequential changes in skeletal muscle and hepatic protein synthesis following sepsis, and their relationship to changes in circulating and tissue glutamine concentrations. Male Wistar rats underwent caecal ligation and puncture (CLP) or sham operation, with starvation, and were killed 24, 72 or 96 h later. A group of non-operated animals were killed at the time of surgery. Protein synthesis was determined using a flooding dose of l-[4-3H] phenylalanine, and glutamine concentrations were measured by an enzymic fluorimetric assay. Protein synthesis in gastrocnemius muscle fell in all groups. Gastrocnemius total protein content was reduced after CLP and at 72 and 96 h after sham operation. After CLP, protein synthesis was lower at 24 h, and total protein content was lower at 72 and 96 h, than in sham-operated animals. CLP was associated with increased liver protein synthesis at all time points, whereas there was no change after sham operation. Liver protein content did not change after CLP, but was lower at 72 and 96 h after sham operation than in non-operated animals. Plasma glutamine concentrations were reduced at 24 h after sham operation, and at 72 and 96 h after CLP. Muscle glutamine concentrations were reduced in all groups, with the decrease being greater following CLP than after sham operation. In the liver, glutamine concentrations were unchanged after CLP, but increased after sham operation. In rats with sepsis, decreases in muscle protein synthesis and content are associated with markedly reduced muscle glutamine concentrations. Plasma glutamine concentrations are initially maintained, but fall later. In liver, protein synthesis is increased, while glutamine concentrations are preserved. These results support a peripheral-to-splanchnic glutamine flux in sepsis.

Prediction of Human Acute Toxicity by the Hep G2/24-hour/Total Protein Assay, with Protein Measurement by the CBQCA Method

2005 ◽  
Vol 33 (3) ◽  
pp. 207-213 ◽  
Author(s):  
Paul J. Dierickx
Keyword(s):  
Protein Content ◽  
Total Protein ◽  
Total Protein Content ◽  
Human Toxicity ◽  
Hep G2 ◽  
Vitro Assay ◽  
Protein Assay ◽  
Lowry Method ◽  
Total Protein Assay

In our previously described Hep G2/24-hour/total protein assay, protein levels were measured by using the Lowry method. This assay was the best acute in vitro assay for the prediction of human toxicity within the Multicentre Evaluation of In Vitro Cytotoxicity (MEIC) study. In order to increase the MEIC data-base with a wider range of chemicals, we were interested in introducing the more practical 3-(4-carboxybenzoyl)-quinoline-2-carboxaldehyde (CBQCA) method for the quantification of the total protein content. Therefore, we investigated whether the same good results for the prediction of acute human toxicity would be obtained with the CBQCA method. The cells were treated for 24 hours, then cytotoxicity was determined by measuring the total protein content with CBQCA. The results were quantified by using the PI50c: the concentration (in mM) of test compound required to reduce the total protein content measured with the CBQCA-method by 50% as compared to the control cells. The results were compared with the PI50, the corresponding value when the Lowry method was used. A relatively low correlation was observed between PI50 and PI50c, reflecting the large and unexpected, differences when using the two protein assays. However, when comparing the log PI50c with the human toxicity, a correlation coefficient of r2 = 0.761 ( n = 44) was obtained for exactly the same series of MEIC chemicals. This value is clearly higher than that for the Lowry method ( r2 = 0.695). Compared to the Lowry method originally used, the Hep G2/24-hour/CBQCA total protein assay has the additional important advantage that it can be very easily adapted for large-scale analyses with robotic systems, including the on-line calculation of the results.

Total protein content and protein synthesis within pre-elongation stage bovine embryos

1998 ◽  
Vol 50 (2) ◽  
pp. 139-145 ◽  
Author(s):  
J.G. Thompson ◽  
A.N.M. Sherman ◽  
N.W. Allen ◽  
L.T. McGowan ◽  
H.R. Tervit
Keyword(s):  
Protein Synthesis ◽  
Protein Content ◽  
Total Protein ◽  
Total Protein Content ◽  
Bovine Embryos

Changes in protein during development of Triturus embryos

Development ◽  
1973 ◽  
Vol 30 (3) ◽  
pp. 647-659
Author(s):  
Hiroshi Imoh ◽  
Tsutomu Minamidani
Keyword(s):  
Protein Synthesis ◽  
Protein Content ◽  
Sodium Carbonate ◽  
Dna Content ◽  
Total Protein ◽  
Soluble Protein ◽  
Nuclear Protein ◽  
Polyacrylamide Gel Electrophoresis ◽  
Tail Bud ◽  
Stage Of Development

The present paper reports basic data on DNA content, protein content, and protein synthesis in Triturus pyrrhogaster embryos during development from cleavage to the hatching stage. Except for measurements of DNA and total protein contents, embryos were labeled with sodium carbonate-14C for 10 h and fractionated into embryonic cell components, i.e. cytoplasmic mass, yolk and pigment granules, and nuclei, in a discontinuous density gradient of sucrose. The protein content and the radioactivity incorporated into protein were measured in each fraction. Those fractions combining protein soluble in buffer at pH 8·3 and in 0·25 N-HCl were further studied with polyacrylamide gel electrophoresis. In the newt embryo, four stages of active DNA increase were observed when cultured at constant temperature; they were gastrula, neurula, late tail-bud, and before-hatching stages. Total protein per embryo decreased from 3 to 2 mg during the development studied. The content of cytoplasmic soluble protein per embryo was low and constant throughout development. Synthesis of the fraction was observed at the earliest stage of development studied though the rate was not high and specific activity of the soluble protein increased during development. Qualitative changes in the newly synthesized protein were observed. With the yolk fraction, synthesis of protein, other than from probable contamination with the cytoplasmic fraction, was not detected and a detailed description was omitted. Changes were observed at two stages of development in the synthesis of nuclear protein soluble in buffer at pH 8·3, the first at gastrulation and the second at late tail-bud stage. The change at gastrulation seemed to be the start of syntheses of the nuclear soluble proteins, while quantitative enhancement rather than qualitative change was noticed at late tail-bud stage. Most of the nuclear protein soluble in 0·25 N-HCI was histone. The histone content increased in accordance with increase in the DNA content and the rate of DNA accumulation was accompanied by proportionate incorporation of radioactivity into histone. Among histone fractions, unique behaviour of the very lysine-rich histone was observed. The availability of [14C]sodium carbonate in rough estimations of protein synthesis in embryos and significance of the data obtained have been discussed.

Effects of growth hormone and an antiserum to rat growth hormone on serum IGF-I and muscle protein synthesis and accretion in the rat

1993 ◽  
Vol 139 (3) ◽  
pp. 395-401 ◽  
Author(s):  
R. M. Palmer ◽  
D. J. Flint ◽  
J. C. MacRae ◽  
F. E. Fairhurst ◽  
L. A. Bruce ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Protein Synthesis ◽  
Protein Content ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Polyclonal Antiserum ◽  
Whole Body ◽  
Total Protein Content ◽  
Plantaris Muscle ◽  
Igf I

ABSTRACT Rats were injected twice daily for up to 10 days with GH or with a polyclonal antiserum to rat GH, commencing at 21–22 days of age. Administration of bovine or human GH (1 mg/day) improved whole body growth rates by 22% and 29% respectively. Plantaris muscle mass was also increased, by 7 and 14% respectively. Anti-GH injected twice daily resulted in a 7% decrease in body weight at 4 days and a 10% reduction by 10 days. Similar decreases were observed in the total protein content of plantaris and soleus muscles. The decrease in the fractional rate of protein synthesis was proportionately greater than the decline in protein content in plantaris muscle whereas in the soleus no change in the rate of protein synthesis was observed, suggesting that the effect on this muscle was due to an increase in the rate of protein degradation. Serum total IGF-I was unchanged by treatment with either GH or anti-GH while the amount of hepatic IGF-I mRNA was also unaffected by anti-GH injection. These data are consistent with a direct effect of GH or an effect mediated by an autocrine/paracrine mechanism of action on muscle but do not support a role for serum total IGF-I as an endocrine mediator of GH action. Journal of Endocrinology (1993) 139, 395–401

Glucocorticoid-induced skeletal muscle atrophy in vitro is attenuated by mechanical stimulation

1992 ◽  
Vol 262 (6) ◽  
pp. C1471-C1477 ◽  
Author(s):  
J. A. Chromiak ◽  
H. H. Vandenburgh
Keyword(s):  
Skeletal Muscle ◽  
Protein Synthesis ◽  
Protein Content ◽  
Total Protein ◽  
Weight Lifting ◽  
Mechanical Activity ◽  
Synthesis Rate ◽  
Protein Synthesis Rate

Glucocorticoids induce rapid atrophy of fast skeletal myofibers in vivo, and either weight lifting or endurance exercise reduces this atrophy by unknown mechanisms. We examined the effects of the synthetic glucocorticoid dexamethasone (Dex) on protein turnover in tissue-cultured avian fast skeletal myofibers and determined whether repetitive mechanical stretch altered the myofiber response to Dex. In static cultures after 3-5 days, 10(-8) M Dex decreased total protein content 42-74%, total protein synthesis rates 38-56%, mean myofiber diameter 35%, myosin heavy chain (MHC) content 86%, MHC synthesis rate 44%, and fibronectin synthesis rate 29%. Repetitive 10% stretch-relaxations of the cultured myofibers for 60 s every 5 min for 3-4 days prevented 52% of the Dex-induced decrease in protein content, 42% of the decrease in total protein synthesis rate, 77% of the decrease in MHC content, 42% of the decrease in MHC synthesis rate, and 67% of the decrease in fibronectin synthesis rate. This in vitro model system will complement in vivo studies in understanding the mechanism by which mechanical activity and glucocorticoids interact to regulate skeletal muscle growth.

scholarly journals A Reassessment of the in vitro total protein content determination (TPC) with SIRC and 3T3 cells for the evaluation of the ocular irritation potential of shampoos: comparison with the in vivo Draize rabbit test

2011 ◽  
Vol 54 (6) ◽  
pp. 1135-1146 ◽  
Author(s):  
Rodrigo Netto Costa ◽  
Clarice Lima do Canto Abreu ◽  
Rosaura Farias Presgrave ◽  
Eloisa Nunes Alves ◽  
Octavio Augusto França Presgrave ◽  
...  
Keyword(s):  
Protein Content ◽  
Total Protein ◽  
Total Protein Content ◽  
3T3 Cells ◽  
Ocular Irritation ◽  
Content Determination

Dose-dependent effects of aluminum on osteocalcin synthesis in osteoblast-like ROS 17/2 cells in culture

2006 ◽  
Vol 263 (6) ◽  
pp. E1113-E1118 ◽  
Author(s):  
P. Fanti ◽  
M. S. Kindy ◽  
S. Mohapatra ◽  
J. Klein ◽  
G. Colombo ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Total Protein ◽  
In Vitro Study ◽  
Total Protein Content ◽  
Dihydroxyvitamin D3 ◽  
Intracellular Content ◽  
High Doses ◽  
Dose Dependent ◽  
Lower Medium

This in vitro study evaluates the effect of aluminum (Al3+) on osteocalcin, a small protein that is produced by the osteoblast. After stimulation with various doses of 1,25-dihydroxyvitamin D3 [1,25(OH)2D3; 10(-11) to 10(-9) M], osteocalcin was consistently lower in the culture medium of ROS 17/2 osteoblastic cells conditioned with 5 microM Al(3+)-saturated transferrin (AlTR) than in apotransferrin (ApoTR)-treated controls. In a second experiment, cultures were conditioned with various doses of AlTR or ApoTR (1.6-8.0 microM) and stimulated with 10(-9) M 1,25(OH)2D3. High doses of AlTR (4.8-8.0 microM) resulted in lower medium and unchanged intracellular content of osteocalcin than treatment with equal amounts of ApoTR. However, in the same experiment, lower doses of AlTR or ApoTR (1.6 and 3.2 microM) yielded different results, i.e., increased medium and intracellular contents of osteocalcin in the Al(3+)-treated cells. Expression of osteocalcin mRNA was not altered in cultures conditioned with low (1.6 microM) or high (8.0 microM) concentrations of AlTR or ApoTR. Similarly, no effect of Al3+ was observed on total protein content, the rate of total protein synthesis, and the degradation of secreted osteocalcin in cultures conditioned with various doses of AlTR or ApoTR. These findings suggest that AlTR affects osteocalcin synthesis in a specific manner, without concomitant effects on the rate of total protein synthesis or on the rate of degradation of osteocalcin. This effect is dose dependent, i.e., low doses of AlTR stimulate and high doses suppress osteocalcin synthesis and/or secretion, and it appears to be posttranscriptional, since the expression of osteocalcin mRNA is not affected.

scholarly journals Regulation of protein metabolism by a physiological concentration of insulin in mouse soleus and extensor digitorum longus muscles. Effects of starvation and scald injury

1979 ◽  
Vol 184 (2) ◽  
pp. 323-330 ◽  
Author(s):  
K N Frayn ◽  
P F Maycock
Keyword(s):  
Protein Synthesis ◽  
Protein Metabolism ◽  
Extensor Digitorum Longus ◽  
Muscle Protein ◽  
Extensor Digitorum ◽  
Total Protein Content ◽  
Skin Thickness ◽  
Physiological Concentration ◽  
Scald Injury

1. Although high concentrations of insulin affect both synthesis and degradation of skeletal-muscle protein, it is not known to what extent these effects occur with physiological concentrations. The effects of a physiological concentration of insulin (100 mu units/ml) on muscle protein synthesis, measured with [3H]tyrosine, and on muscle protein degradation, measured by tyrosine release in the presence of cycloheximide, were studied in mouse soleus and extensor digitorum longus muscles in vitro. 2. Insulin significantly stimualated protein synthesis in both muscles, but an inhibition of degradation was seen only in the extensor digitorum longus. 3. Starvation for 24 h decreased the rate of protein synthesis and increased the rate of breakdown in the extensor digitorum longus. Sensitivity to insulin-stimulation of proteins synthesis in the soleus was increased by starvation. 4.;a 20%-surface-area full-skin-thickness dorsal scald injury produced a fall in total protein content in soleus and extensor digitorum muscles, maximal on the third day after injury. Soleus muscles 2 days after injury showed an impairment of protein synthesis; degradation was unaffected and neither synthesis nor degradation in vitro was significantly affected in the extensor digitorum longus. 5. The advantages and limitations of studies of protein metabolism in vitro are discussed.

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