Urinary mercapturic acids as markers for the estimation of isothiocyanate release in the digestive tract of rats following oral adminstration of glucosinolates

1995 ◽  
Vol 1995 ◽  
pp. 181-181
Author(s):  
A.J. Duncan ◽  
T. Acamovic ◽  
I.I. Onaga

Glucosinolates are a group of plant thioglucosides, found in a range of plant genera, notably the Brassicae. Glucosinolates assume agricultural importance because of their presence in rapeseed meal and forage brassica crops whose nutritional value they may limit. Glucosinolates are hydrolysed under the action of plant or microbial myrosinase to release a range of toxic metabolites (see Duncan, 1991). For example, sinigrin, a commonly found glucosinolate, breaks down to allyl isothiocyanate (AITC) and allyl cyanide as well as a number of lesser components. The course of hydrolysis is influenced by characteristics of the hydrolysis environment such as pH and the presence of metallic ions and enzymic co-factors. Because of the varied nature of the effects of different glucosinolate metabolites, the course of hydrolysis is a key influence on the ultimate toxicity of glucosinolates. Little is known, however, of the identity of metabolites arising in the digestive tract of livestock under different dietary circumstances. This is due, in part, to the technical difficulties associated with measuring concentrations of the compounds in the digestive tract. An alternative approach to the study of glucosinolate hydrolysis in vivo is to measure concentrations of ultimate excretory products and relate this to events earlier in the catabolic pathway. For example, isothiocyanates are excreted as their mercapturic acid derivatives in rats and thus provide potentially useful markers for estimating rates of release of isothiocyanates from sinigrin in vivo (Mennicke et al. 1983). In the experiment reported here, this approach was validated in rats and used to measure rates of release of AITC from sinigrin in animals consuming diets with or without added myrosinase.

1995 ◽  
Vol 1995 ◽  
pp. 181-181
Author(s):  
A.J. Duncan ◽  
T. Acamovic ◽  
I.I. Onaga

Glucosinolates are a group of plant thioglucosides, found in a range of plant genera, notably theBrassicae. Glucosinolates assume agricultural importance because of their presence in rapeseed meal and forage brassica crops whose nutritional value they may limit. Glucosinolates are hydrolysed under the action of plant or microbial myrosinase to release a range of toxic metabolites (see Duncan, 1991). For example, sinigrin, a commonly found glucosinolate, breaks down to allyl isothiocyanate (AITC) and allyl cyanide as well as a number of lesser components. The course of hydrolysis is influenced by characteristics of the hydrolysis environment such as pH and the presence of metallic ions and enzymic co-factors. Because of the varied nature of the effects of different glucosinolate metabolites, the course of hydrolysis is a key influence on the ultimate toxicity of glucosinolates. Little is known, however, of the identity of metabolites arising in the digestive tract of livestock under different dietary circumstances. This is due, in part, to the technical difficulties associated with measuring concentrations of the compounds in the digestive tract. An alternative approach to the study of glucosinolate hydrolysisin vivois to measure concentrations of ultimate excretory products and relate this to events earlier in the catabolic pathway. For example, isothiocyanates are excreted as their mercapturic acid derivatives in rats and thus provide potentially useful markers for estimating rates of release of isothiocyanates from sinigrinin vivo(Mennickeet al. 1983). In the experiment reported here, this approach was validated in rats and used to measure rates of release of AITC from sinigrin in animals consuming diets with or without added myrosinase.


2021 ◽  
Author(s):  
Alia A. Shoeib ◽  
Nader A. Ashmawy ◽  
Ayman Kamal ◽  
Sahar Abd El Fatah Zaki

Abstract The antibacterial activity of Cu, Fe, Co, and ZnNPs which were formed by Enterococcus thailandicus, Pseudomonas putida, Marinobacter hydrocarbonoclasticus, and P. geniculate sequentially was tested against some soft rot/blackleg genera. The effects of NPs were recorded on bacterial DNA, proteins, and carbohydrates concentration of Pectobacterium carotovorum, Enterobacter cloacae (soft rot), and Dickeya solani (soft rot/blackleg). Treated cells showed degradation in the DNA isolated, and a decrease in proteins, and carbohydrates concentration compared with untreated cells. The treated cells using SEM showed collapsed, and small pits in the cell wall. Internal changes using TEM showed penetration of NPs inside the tested bacterial cells, the appearance of periplasmic space, formation vacuoles, and condensation of cytoplasm. Disease severity ex vivo of tuber infected with tested genera demonstrated that NPs treatment didn't show any rotted tissue compared with untreated. FeNPs were tested to control soft rot/blackleg disease caused by D. solani in comparison with copper pesticide. Present data recorded an increase in shoot and root length, in addition to, increase in dry and fresh weight, compared with either infected or healthy plants. In studying the ability of treated potato (Solanum tuberosum) seedlings with NPs to uptake and accumulate FeNPs from the soil, ICP-OES recorded a small increase in Fe content of treated plants compared with untreated. FeNPs can be used to control soft rot/blackleg disease caused by D. solani instead of copper pesticide and can be considered as a new and alternative approach to traditional disease management methods, and also increase the nutritional value of the plants


1995 ◽  
Vol 23 (1) ◽  
pp. 61-73
Author(s):  
Coenraad Hendriksen ◽  
Johan van der Gun

In the quality control of vaccine batches, the potency testing of inactivated vaccines is one of the areas requiring very large numbers of animals, which usually suffer significant distress as a result of the experimental procedures employed. This article deals with the potency testing of diphtheria and tetanus toxoids, two vaccines which are used extensively throughout the world. The relevance of the potency test prescribed by the European Pharmacopoeia monographs is questioned. The validity of the potency test as a model for the human response, the ability of the test to be standardised, and the relevance of the test in relation to the quality of the product are discussed. It is concluded that the potency test has only limited predictive value for the antitoxin responses to be expected in recipients of these toxoids. An alternative approach for estimating the potency of toxoid batches is discussed, in which a distinction is made between estimation of the immunogenic potency of the first few batches obtained from a seed lot and monitoring the consistency of the quality of subsequent batches. The use of animals is limited to the first few batches. Monitoring the consistency of the quality of subsequent batches is based on in vitro test methods. Factors which hamper the introduction and acceptance of the alternative approach are considered. Finally, proposals are made for replacement, reduction and/or refinement (the Three Rs) in the use of animals in the routine potency testing of toxoids.


1977 ◽  
Vol 57 (2) ◽  
pp. 279-288 ◽  
Author(s):  
S. O. THORLACIUS

Digestibility and intake of diets containing 8, 28, 48 or 68% ground wheat straw plus ground crested wheatgrass and rapeseed meal, and diets containing 33, 48, 63 and 78% ground crested wheatgrass plus barley and rapeseed meal was measured with four yearling wethers per diet. Digestible energy (DE) content ranged from 2.07 to 2.95 kcal/g dry matter (DM) and dry matter digestibility (DMD) (%) from 48.7 to 71.1%. Regression of DE intake y (kcal/w0.75kg/d) on DE content (x) was curvilinear; y = −2,133 + 1,626x − 277.9x2, r = 0.996, P < 0.01, SE = ± 7.3. There was also a curvilinear relationship between diet density, as fed, (x) g (DM)/ml and DMD (%), y = 9.057 + 364.1x − 530.0x2, r = 0.970, P < 0.01, SE = ± 2.4. A linear regression equation was calculated over the DE range (2.07–2.52) for which there was an obvious increase in DE intake with increasing diet DE content; y = −700.6 + 361x, r = 0.994, P < 0.01, SE = ± 9.4, y = DE intake (kcal/w0.75kg/d), x = DE [kcal/g (DM)]. Using this regression equation and assuming a linear increase in DE intake with increase in diet DE content up to a point at which the apparent energy demand of the animal is satisfied gave a more accurate prediction of DE intake than when the curvilinear regression equation, y = −2,133 + 1,626x − 277.9x2, was used empirically. Accuracy of the prediction was further improved by expressing DE/unit ration volume instead of per unit DM. The sheep used in the present experiments had an apparent energy demand of 230 kcal/w0.75kg/day which was met at diet DE contents above 0.48 kcal/ml or 2.6 kcal/g (DM). There was a high correlation between in vivo DE content of the diet, y [kcal/g (DM)] and in vitro (x) digestible organic matter content, x, (%), r = 0.991, P < 0.01, y = 0.38 + 0.037x, SE = ± 0.04.


2017 ◽  
Vol 8 ◽  
Author(s):  
Giovanna Ponte ◽  
Antonio V. Sykes ◽  
Gavan M. Cooke ◽  
Eduardo Almansa ◽  
Paul L. R. Andrews

2001 ◽  
Vol 280 (5) ◽  
pp. H2006-H2010 ◽  
Author(s):  
David J. Christini ◽  
Jeff Walden ◽  
Jay M. Edelberg

Dynamic regulation of biological systems requires real-time assessment of relevant physiological needs. Biosensors, which transduce biological actions or reactions into signals amenable to processing, are well suited for such monitoring. Typically, in vivo biosensors approximate physiological function via the measurement of surrogate signals. The alternative approach presented here would be to use biologically based biosensors for the direct measurement of physiological activity via functional integration of relevant governing inputs. We show that an implanted excitable-tissue biosensor (excitable cardiac tissue) can be used as a real-time, integrated bioprocessor to analyze the complex inputs regulating a dynamic physiological variable (heart rate). This approach offers the potential for long-term biologically tuned quantification of endogenous physiological function.


1980 ◽  
Vol 58 (2) ◽  
pp. 141-146 ◽  
Author(s):  
B. Oštádal ◽  
A. Babický ◽  
J. Kopoldová

Seven-day-old embryos received 3.7 × 105 Bq (10 μCi) of [3H]isoprenaline (IPRO) hydrochloride intraamnially. The capacity of myocardial and liver tissue for taking up administered catecholamine increased rapidly during the first 10 min after administration. The peak concentration (disintegrations per minute per milligram) in the heart, however, was significantly lower as compared with the liver. Thereafter the uptake in both organs markedly decreased and reached its lowest values between 15 and 30 min. From then on, the concentration of the tritium-labelled compound increased again and 6 h after administration it attained the second peak in both organs. This value was more than five times higher in the liver as compared with the myocardium.Radiometric evaluation of chromatograms from myocardial and liver extracts has revealed that IPRO is rapidly metabolized to 3-O-methyl IPRO. The proportion of this fraction in both organs represents approximately 40% of total radioactivity as early as 5 min after administration.The time course of IPRO uptake indicates that the following factors may participate in the development of cardiac and hepatic lesions: (a) IPRO immediately after administration, and (b) subsequently its toxic metabolites.


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.


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