Effect of different oxygen concentrations in the gas phase on biochemical activities of goat mammary tissue in organ culture

1989 ◽  
Vol 56 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Josef Škarda ◽  
Eva Urbanová

SummaryNon-secretory mammary expiants from virgin goats showed higher RNA and protein synthesis in a low O2 gas phase (air) than in high O2 (95% O2). Lipid and casein synthesis was not affected significantly by the concentration of O2 in the atmosphere during culture. on the other hand, the more developed mammary tissue from primigravid goats showed higher lipid, casein and protein synthesis in 95% O2. The relative response of mammary tissue to hormones was not substantially different when cultured in the presence of a low or high O2 gas phase. As Hepes-buffered medium was found not to need a supply of CO2 to maintain the correct pH and as Hepes did not interfere with biochemical activities of cells, it is recommended to use it for cultures in a low O2 gas phase.

1974 ◽  
Vol 77 (1) ◽  
pp. 64-70 ◽  
Author(s):  
Gustav Wägar

ABSTRACT Whether the short-term regulation of thyroidal protein synthesis by TSH occurs at the transcriptional or the translational level was tested by measuring the effect of actinomycin D (act D) on the TSH-induced stimulation of L-14C-leucine incorporation into the thyroidal proteins of rats. TSH was injected 6 h before the rats were killed. The thyroid glands were then removed and incubated in vitro in the presence of L-14C-leucine for 2 h. The pronounced stimulation of leucine incorporation in the TSH-treated animals was depressed as compared with controls but still significant even when the animals had been pre-treated with 100 μg act D 24 and 7 h before sacrifice. On the other hand, act D strongly decreased incorporation of 3H-uridine into RNA. Short-term regulation of thyroidal protein synthesis by TSH appears to be partly but not wholly dependent on neosynthesis of RNA. Hence regulation may partly occur at the translation level of protein synthesis.


The work described in this and the following paper is a continuation of that in parts I and II, devoted to elucidation of the mechanism of the reactions of methylene with chloroalkanes, with particular reference to the reactivities of singlet and triplet methylene in abstraction and insertion processes. The products of the reaction between methylene, prepared by the photolysis of ketene, and 1-chloropropane have been identified and estimated and their dependence on reactant pressures, photolysing wavelength and presence of foreign gases (oxygen and carbon mon­oxide) has been investigated. Both insertion and abstraction mechanisms contribute significantly to the over-all reaction, insertion being relatively much more important than with chloroethane. This type of process appears to be confined to singlet methylene. If, as seems likely, there is no insertion into C—Cl bonds under our conditions (see part IV), insertion into C2—H and C3—H bonds occurs in statistical ratio, approximately. On the other hand, the chlorine substituent reduces the probability of insertion into C—H bonds in its vicinity. As in the chloroethane system, both species of methylene show a high degree of selectivity in their abstraction reactions. We find that k S Cl / k S H >7.7, k T Cl / k T H < 0.14, where the k ’s are rate constants for abstraction, and the super- and subscripts indicate the species of methylene and the type of atom abstracted, respectively. Triplet methylene is discriminating in hydrogen abstraction from 1-C 3 H 7 Cl, the overall rates for atoms attached to C1, C2, C3 being in the ratios 2.63:1:0.


1983 ◽  
Vol 59 (1) ◽  
pp. 121-131
Author(s):  
P. Isberner ◽  
G. Cleffmann

Cytosol from Tetrahymena cells growing at different rates was isolated and separated by centrifugation into polysomal and non-polysomal fractions. The RNAs of either fraction were separated chromatographically into poly(A)+ RNA and poly(A)-RNA. It was found that in resting cultures the total RNA per cell is only about half of that of rapidly growing cultures. All fractions of RNA were reduced proportionally. Thus, the percentage of polysomally bound total RNA (70% of cytosol RNA) and polysomally bound poly(A)+ RNA (72% of cytosol poly(A)+ RNA) is the same in growing and resting cultures. Differences, however, were found in the polysomal structure. Polysomes from resting cultures contained significantly fewer ribosomes. The amounts of RNA bound to polysomes were related to the rate of protein synthesis under different growth conditions. The decrease in cellular RNA corresponded well with the reduction in amino acid incorporation in resting cells. The rate of protein accumulation in resting cells, on the other hand, was considerably less, suggesting that polypeptides in resting cultures are less stable.


BIBECHANA ◽  
2016 ◽  
Vol 14 ◽  
pp. 66-76
Author(s):  
Nabin Kumar Raut ◽  
Hari Prasad Lamichhane

The present work enumerates detailed computational investigation into the IR spectra in gas phase and in solvent of 1, 4- Benzoquinone family (benzoquinone (BQ), duroquinone (DQ), plastoquinone (PQ), ubiquinone (UQ), and dimethoxy dimethyl benzoquinone (MQo)). In  the spectra of BQ, PQ, and DQ, we observed separate intense carbonyl (C=O) and C=C bands respectively around 1730 cm-1 (intense), 1645 cm-1 (weak). On the other hand, for UQ and MQo, three prominent bands around 1652, 1703, and 1733 cm-1 were observed, where two C=O modes were uncoupled but one of the carbonyl is strongly coupled with C=C vibrations. The additional methyl groups downshift the intense carbonyl bands and upshift C=C mode frequencies. The carbonyl modes further downshifted in the solvent phase calculation.BIBECHANA 14 (2017) 66-76


1971 ◽  
Vol 50 (2) ◽  
pp. 241-249 ◽  
Author(s):  
D. Y. WANG ◽  
VICKY AMOR

SUMMARY The rates of synthesis of DNA, RNA and protein of mouse mammary gland explants in organ culture have been determined. Stimulation with insulin resulted in maximal rates of synthesis of these components, all occurring between 18 and 22 h of culture. The use of metabolic inhibitors of DNA, RNA or protein synthesis showed that after insulin stimulation, inhibition of any one of these processes was associated with a reduction in the synthesis of the other two components. Also the maximal rate of protein synthesis is governed by the net amount of RNA formed throughout the period of culture. Evidence is presented that the stimulation of DNA, RNA or protein synthesis by insulin is not due to increased transport of amino acids and that insulin appears to act rapidly on processes which subsequently lead to enhanced synthetic activity.


1980 ◽  
Vol 35 (5) ◽  
pp. 568-577 ◽  
Author(s):  
Peter Paetzold ◽  
Günther Schimmel

1,3-Dipolar reagents with an unsaturated CNO- or CNN-skeleton undergo 1,3-organoboration by triorganoboranes. On the other hand, the unsaturated NNO-skeletons in azoxybenzene or nitrous-oxide are reduced to the corresponding NN-fragment by trialkylboranes. The 1,3-addition of aminoborane Cl2BNMe2 to the aldimineoxide PhHC = NMe-0 represents one of the rare examples of analogous reactivity of BN- and CC-double bonds. O-Borylhydroxylamines PhHCR-NMe-OBR2 are reduced by BR′3 to PhHCR-NMe-BR′2 and R′0-BR2. Similar reduction products are isolated from liquid-phase thermolysis of PhHCEt-NMe-OBEt2 (16), whereas gas-phase thermolysis of 16 gives PhCH = NMe, (EtBO)3, and C4H10.


2007 ◽  
Vol 277 ◽  
pp. 1-3 ◽  

In a nutshellExercise increases oxidation of amino acids such as leucine.On the other hand, leucine is a powerful mediator of protein synthesis in muscle, promoting improved function, reduced fatigue and enhanced recovery from exertion. There is RCT evidence that leucine improves sports performance, particularly for endurance activity, but more evidence is still needed.


2015 ◽  
Vol 46 (1) ◽  
pp. 101-118
Author(s):  
Aldona Rennert

The dynamics of growth and changes in nucleic acid and protein contents in sunflower calluses and tumours cultured in hydroxyurea (HU) containing media were examined. HU-induced changes in healthy tissues ran in parallel always in the same direction, in tumourous ones however an uncoupling between DNA synthesis and tissue growth on one hand and RNA and protein synthesis on the other took place. A detailed analysis of the results allows to suppose that the specific activity of HU on tumourous tissue could be an index of: 1) quantitative disturbances in its genes function (2) degree of the lass of sensitivity to the factors of regulation.


Blood ◽  
1968 ◽  
Vol 31 (3) ◽  
pp. 292-303 ◽  
Author(s):  
YATARO YOSHIDA ◽  
AKIO TODO ◽  
SHIGERU SHIRAKAWA ◽  
GYOICHI WAKISAKA ◽  
HARUTO UCHINO

Abstract In order to elucidate the nature of the megaloblastic lesion at the cellular level, DNA, RNA, and protein synthesis was studied in megaloblasts of pernicious anemia. While microphotometric estimation of DNA content showed an increase in cells with DNA values ranging around the 4c value, autoradiographic studies with H3-thymidine indicated, rather, a decreased ability to synthesize DNA. Combined microphotometric and autoradiographic studies suggested the impaired DNA synthesis with occasional arrests of synthesis, as well as the prolongation of the S period with or without the prolongation of the G2 period. On the other hand, active incorporation of H3-uridine and H3-leucine indicated active or unaffected RNA and protein synthesis. Vitamin B12 treatment rapidly corrected these aberrant patterns of synthesis. The significance of these findings has been discussed in relation to the mechanism of megaloblastic hemopoiesis.


1968 ◽  
Vol 59 (2) ◽  
pp. 193-202
Author(s):  
H. Kröner ◽  
W. Staib

ABSTRACT By measuring protein, RNA and DNA in skeletal muscle and spleen we were unable to demonstrate an enhanced catabolism due to cortisol. On the other hand we could demonstrate a reduced anabolism by diminished incorporation of 14C labelled leucin in protein of muscle, spleen and skin. Simultaneously an increase of ATP and an equivalent decrease of ADP were found in connective tissue, which were regarded as a consequence of reduced energy consumption. In skeletal muscle a decrease of energy consumption due to cortisol was only indirect demonstrable by reduced glycolysis when oxidative metabolism was eliminated for a short time. It seems obvious, that inhibition of protein synthesis causes the diminished energy consumption.


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