GROWTH-DEPRESSING FACTORS IN RAPESEED OIL MEAL: VII. EFFECTS OF MYROSINASE ACTIVITY ON TOXICITY FOLLOWING TREATMENT WITH BUFFERED SOLUTIONS

1966 ◽  
Vol 46 (3) ◽  
pp. 165-169 ◽  
Author(s):  
R. J. Belzile ◽  
J. M. Bell

Solvent-process, uncooked rapeseed meal of Brassica napus L. (summer) origin was autoclaved at 0.7 kg/cm2 to destroy myrosinase and compared with uncooked meal. Each type of meal was treated with buffer solutions at pH 3.0, 6.0, and 9.0 for 1 hour at temperatures of 22 °C and 50 °C. Unextracted meals were air-dried after buffer solution treatment; extracted meals were filtered under vacuum and washed twice with similar buffer solution before drying. The resulting meals were assayed chemically for isothiocyanate (I) and oxazolidinethione (O) and tested for toxicity with mice using diets containing up to 0.07% I+O.Treatment of myrosinase-free rapeseed meal at any pH resulted in no apparent change in toxicity provided the sample was not filtered. Extraction of soluble matter removed over 80% of the I+O, but growth was depressed on meal processed at pH 3.0. Some of the thioglucosides apparently were converted into other non-water-soluble compounds.Exposure of enzyme-active meal to buffer solutions without subsequent filtration resulted in a one-third reduction in I+O at pH 3.0, one-half reduction at pH 6.0, and two-thirds reduction at pH 9.0. Further losses occurred upon filtration but all of these meals contained significantly more I+O than did enzyme-free meals similarly processed. Chemically determined I and O may fail to measure the potential toxicity of rapeseed meals in which enzyme activity has occurred.

1963 ◽  
Vol 43 (1) ◽  
pp. 169-173 ◽  
Author(s):  
R. Belzile ◽  
J. M. Bell ◽  
L. R. Wetter

A study was made of the effects of adding 0.1 per cent myrosinase (a thioglucoside-splitting enzyme) to mouse diets containing Swedish or Polish type rapeseed oil meal and hot water-treated fractions of the meal. The latter were devoid of active enzyme but contained known quantities of the thioglucosides, precursors of the toxic isothiocyanates (I) and thiooxazolidones (T).Hot water extraction of the meals resulted in about 20 per cent of the dry matter being extracted and in significant alteration in the proportions and amounts of I and T.The addition of myrosinase to untreated rapeseed oil meals failed to increase the toxicity, presumably because there was already sufficient enzyme in the meals to reduce gains to about 25 per cent of normal. Addition of enzyme to the extracted residue (containing about one-third of the original thioglucosides of the meal) also failed to increase the toxicity. Enzyme addition to diets containing the water-soluble components resulted in significant growth depression but the full potential toxicity was not obtained.It is concluded that the enzyme myrosinase is an important factor affecting the toxicity of rapeseed oil meal in animal feeding, although conditions for its optimum activity were not achieved in this experiment where semi-purified enzyme was employed as a dietary supplement.


1965 ◽  
Vol 16 (4) ◽  
pp. 649 ◽  
Author(s):  
GR Pearce

The circadian (24-hr) pattern of rumination of caged sheep was found to be affected: (a) by the administration of a roughage ration per fistulam; (b) by the emptying of the rumen and the subsequent return of the rumen contents; (c) by the emptying of the rumen and the replacement of the contents by a buffer solution plus roughage. The period during which no rumination occurred following feeding was progressively shortened when increasing proportions of a ration of oaten chaff and lucerne chaff were administered per fistulam. The effect was much reduced when high protein sheep cubes were added to the chaff ration. The removal of the rumen contents after voluntary feeding and then their immediate return to the rumen tended to cause an early commencement of rumination. When the rumen contents were "pasteurized" before return, however, rumination did not occur for an extended period afterwards. When the rumen contents were replaced with buffer solutions plus roughage, variable rumination responses occurred. In one instance apparently uninhibited rumination resulted.


1975 ◽  
Vol 55 (1) ◽  
pp. 61-70 ◽  
Author(s):  
J. M. BELL

Five swine experiments were conducted to evaluate rapeseed meal (RSM) of low glucosinolate content (Brassica napus L. cv. Bronowski). Two experiments involved 0, 25, 50, 75 and 100% substitution of either Bronowski meal or regular (B. campestris) meal for soybean meal or fishmeal used in the control diet. One experiment compared ad libitum-fed and partially restricted pigs. Another experiment involved digestibility studies, and the final one involved methionine and lysine supplementation. As the dietary levels of either Bronowski or regular RSM increased in the ration, protein digestion coefficients decreased from 79 and 80% to 76 and 78%, respectively, and energy coefficients decreased from 82% to 79 and 78%, respectively. The protein and energy digestibility coefficients for Bronowski RSM were estimated to be 68 and 59%; for regular RSM, 65 and 54%. With barley–wheat–RSM diets, pigs responded to 0.1% methionine, but not to lysine (P > 0.05). Pigs fed ad libitum consumed more Bronowski than regular RSM diet and performed as well as pigs fed soybean meal diets.


1938 ◽  
Vol 68 (4) ◽  
pp. 607-627 ◽  
Author(s):  
Joseph E. Smadel ◽  
Edward G. Pickels ◽  
Theodore Shedlovsky

Ultracentrifugal studies of the CL dermal strain of vaccine virus warrant the following conclusions: 1. When suspended in increasing concentrations of sucrose, glycerol, or urea solutions, elementary bodies of vaccinia show variations in sedimentation rate which indicate changes in the density or size of the particles. For a given change in the density of the medium these changes are smallest with sucrose and most marked with urea. The normal rate of sedimentation of Paschen bodies may be restored by resuspending them in dilute buffer solution. 2. The density of elementary bodies of vaccinia suspended in dilute buffer solutions is estimated to be 1.16 gm. per cc. Higher values for the density are found if the particles are suspended in solutions containing sucrose, glycerol, or urea. In 53 per cent sucrose, for example, the density is 1.25 gm. per cc. 3. Paschen bodies appear to be quite permeable to water and urea, less so to glycerol, and only slightly, if at all, to sucrose. 4. The increased density of the elementary bodies of vaccinia in sucrose solutions may be accounted for by an osmotic extraction of water from the particles. On this basis the water which can be thus extracted corresponds to at least a third of the original volume of the particles.


1963 ◽  
Vol 41 (1) ◽  
pp. 1-7 ◽  
Author(s):  
H. Reisener ◽  
A. J. Finlayson ◽  
W. B. McConnell

When uredospores of Puccinia graminis var. tritici race 15B were shaken in a medium containing M/30 phosphate buffer, pH 6.2, and valerate-2-C14, about 88% of the radioactivity was removed from the buffer solution in a period of 3 hours. About 40% of the carbon-14 taken from the buffer was found in a water-soluble extract of the spores and about 15% was respired as carbon dioxide. The result is compared with an earlier report that carbon 1 of valerate is more extensively released as carbon dioxide and less extensively incorporated into spore components. Glutamic acid, glutamine, γ-aminobutyric acid, and alanine of high specific activity were isolated. It was estimated from partial degradation that more than one-half of the carbon-14 of glutamic acid occurred in position 4 and that carbon 5 was very weakly labelled. Citric acid was also of high specific activity and was labelled predominantly in the internal carbons.It is concluded that respiring rust spores utilize externally supplied valerate by β-oxidation, which releases carbons 1 and 2 in a form which is metabolized as acetate by the tricarboxylic acid cycle.


1975 ◽  
Vol 21 (12) ◽  
pp. 1791-1794 ◽  
Author(s):  
Bernd Rietz ◽  
George G Guilbault

Abstract We describe enzymatic fluorometric methods for determining activities of serum alkaline phosphatase and of serum acid phosphatase in solution and on silicone rubber pads. 4-Methylumbelliferone phosphate is used as substrate, in either tris(hydroxymethyl)aminomethane or citrate buffer. In solution, the reaction is measured at 37 °C in a 3-ml Pyrex cuvette. Measurements on the pads are also made at 37 °C, after establishing a stable substrate film by lyophilizing all reagents on the surface of the pads. Only 20 to 30 µl of substrate solution, 50 µl of buffer solution, and 1 to 10 µl of blood are necessary, making a total volume of 51 to 60 µl for each assay. The rate of appearance of the fluorescent 4-methylumbelliferone liberated from 4-methylumbelliferone phosphate by the enzymatic action is measured and equated to enzyme activity. Calibration plots of the change in fluorescence per minute vs. enzyme activity for measurements in solution and on pads show a good proportionality in the range of 30.8 to 633 U/liter for alkaline phosphatase and in the range of 0.265 to 5.3 King— Armstrong units for acid phosphatase, indicating the usefulness of these methods in the clinical laboratory.


1950 ◽  
Vol 91 (6) ◽  
pp. 655-664 ◽  
Author(s):  
Armin F. Schick ◽  
George M. Hass

A new method for the isolation of large numbers of individual myofibrils from fresh mammalian skeletal and cardiac muscle has been described. Purification of isolated myofibrils was accomplished by differential centrifugation of fresh frozen sections of muscle which had been mechanically agitated after exposure for 30 to 45 minutes at 0°C. to the action of a dilute solution of trypsin in a phosphate buffer solution with a pH of 7.0 and an ionic strength of 0.25. Isolated skeletal myofibrils of the rabbit and man have similar constant solubility properties. They dissolve in an aqueous mixture of 0.5 N potassium chloride and 0.03 N sodium bicarbonate, giving viscous solutions which exhibit conspicuous birefringence of flow. They are soluble in buffer solutions (ionic strength 0.15) on the acid side of pH 4 and alkaline side of pH 10. If the ionic strength of potassium phosphate buffer solutions is increased to 0.5 or if the ionic strength of phosphate-borate buffer solutions is increased to a similar value by addition of potassium chloride, the isolated myofibrils become soluble at neutrality. Hence, it is possible, first to isolate the myofibrils and then dissolve them without deviating appreciably from physiologic ranges of pH. The extent to which myofibrils are modified by the conditions imposed by the method of isolation is unknown. There is no significant change in microscopic structure or optical birefringence. Furthermore, there is retention of a form of physiological reactivity, for when the isolated skeletal myofibrils are immersed in solutions of adenosinetriphosphate, they promptly and irreversibly change from elongated fibrils with distinct structural detail into dense spherical masses without recognizable microscopic structure.


2018 ◽  
Vol 14 ◽  
pp. 2236-2241 ◽  
Author(s):  
Xiayang Huang ◽  
Xinghua Zhang ◽  
Tianxin Qian ◽  
Junwei Ma ◽  
Lei Cui ◽  
...  

A water-soluble 2,2′-biphen[4]arene (2,2’-CBP4) containing eight carboxylato moieties was synthesized and characterized. Its complexation behavior towards two alkaloids, palmatine (P) and berberine (B), was investigated by means of fluorescence and 1H NMR spectroscopy in aqueous phosphate buffer solution (pH 7.4). In the presence of 2,2’-CBP4, 1H NMR signals of P and B displayed very large upfield shifts, indicating the formation of inclusion complexes with strong binding affinities. Fluorescence titration experiments showed that P and B exhibited dramatic fluorescence enhancement of more than 600 times upon complexation with 2,2’-CBP4. Particularly, the fluorescence intensity is strong enough to be readily distinguished by the naked eye. Although the two guests have similar structures, the association constant of B with 2,2’-CBP4 (K a = (2.29 ± 0.27) × 106 M−1) is 3.9 times larger than that of P (K a = (5.87 ± 0.24) × 105 M−1).


2019 ◽  
Vol 56 (6) ◽  
pp. 3090-3098
Author(s):  
Hristo Kalaydzhiev ◽  
Vanya D. Gandova ◽  
Petya Ivanova ◽  
Teresa R. S. Brandão ◽  
Tzvetelin T. Dessev ◽  
...  

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