SOP/MET/233 Collection of Excreta from Dogs to which Radiolabelled Test Substance has been Administered

1981 ◽  
pp. 231-232
Author(s):  
I. P. Sword ◽  
A. W. Waddell
Keyword(s):  
Test Substance

IN SITU AND PILOT ORGAN PERFUSION TECHNIQUES FOR THE STUDY OF METABOLIC DYNAMICS

1972 ◽  
Vol 68 (2_Supplb) ◽  
pp. S9-S25 ◽  
Author(s):  
John Urquhart ◽  
Nancy Keller
Keyword(s):  
Cardiac Output ◽  
Large Fraction ◽  
Experimental Studies ◽  
Test Substance ◽  
Organ Perfusion ◽  
Systemic Blood ◽  
Experimental Control ◽  
Arterial Blood ◽  
Vascular Connections

ABSTRACT Two techniques for organ perfusion with blood are described which provide a basis for exploring metabolic or endocrine dynamics. The technique of in situ perfusion with autogenous arterial blood is suitable for glands or small organs which receive a small fraction of the animal's cardiac output; thus, test stimulatory or inhibitory substances can be added to the perfusing blood and undergo sufficient dilution in systemic blood after passage through the perfused organ so that recirculation does not compromise experimental control over test substance concentration in the perfusate. Experimental studies with the in situ perfused adrenal are described. The second technique, termed the pilot organ method, is suitable for organs which receive a large fraction of the cardiac output, such as the liver. Vascular connections are made between the circulation of an intact, anaesthetized large (> 30 kg) dog and the liver of a small (< 3 kg) dog. The small dog's liver (pilot liver) is excised and floated in a bath of canine ascites, and its venous effluent is continuously returned to the large dog. Test substances are infused into either the hepatic artery or portal vein of the pilot liver, but the small size of the pilot liver and its blood flow in relation to the large dog minimize recirculation effects. A number of functional parameters of the pilot liver are described.

In vivo evidence for dopaminergic regulation of the canine pituitary intermediate lobe

1986 ◽  
Vol 113 (4) ◽  
pp. 471-478 ◽  
Author(s):  
R. J. Kemppainen ◽  
J. L. Sartin
Keyword(s):  
Dopamine Antagonist ◽  
Test Substance ◽  
Intermediate Lobe ◽  
Adrenergic Agonist ◽  
Serotonin Agonist ◽  
Dopaminergic Pathway ◽  
Pre Treatment ◽  
Pituitary Intermediate Lobe ◽  
Dopaminergic Regulation

Abstract. In order to examine regulation of pituitary intermediate lobe secretion, plasma immunoreactive (i)ACTH, cortisol, and α-MSH responses to iv bolus injections of CRF, quipazine maleate (serotonin agonist), isoproterenol (β-adrenergic agonist) or haloperidol (dopamine antagonist) were determined in conscious, unrestrained dogs. Endocrine responses to these test substances were also determined in dogs pre-treated with dexamethasone. Administration of one or more doses of each test substance resulted in significant elevations in plasma iACTH and cortisol concentrations. Only haloperidol injection caused significant increases in plasma iα-MSH. Following dexamethasone pre-treatment, plasma iACTH and cortisol increases in response to all test substances were considerably reduced or abolished. Dexamethasone did not alter baseline or haloperidol-stimulated plasma ia-MSH concentrations. However, infusion of bromocriptine mesylate (dopamine agonist) in combination with dexamethasone pre-treatment reduced the plasma iα-MSH response to haloperidol. We conclude that a dopaminergic pathway is important in the in vivo regulation of pituitary intermediate lobe activity in dogs.

Liver Toxicity in Rats Fed A Mixture of Pcb Congeners and 2,3,7,8-Tcdd

1997 ◽  
Vol 3 (S2) ◽  
pp. 51-52
Author(s):  
B.J. Cornell ◽  
A. Singh ◽  
I. Chu
Keyword(s):  
Aromatic Compounds ◽  
Liver Toxicity ◽  
Corn Oil ◽  
Morphological Changes ◽  
Test Substance ◽  
Sprague Dawley ◽  
Morphological Alterations ◽  
Pcb Congeners ◽  
Transmission Electron ◽  
Sprague Dawley Rats

Polyhalogenated aromatic compounds such as polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins (PCDDs) continue to be environmental contaminants because of their bioaccumulation in the food chain and high resistance to biodegradation. The current study was undertaken to determine if a mixture of PCB congeners (WHO-IPCS) were interactive with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in producing morphological changes in the rat liver. Both compounds are known to produce a broad range of biochemical and morphological alterations including enzyme induction.Groups (N=5) of female Sprague-Dawley rats were administered TCDD (0, 2.5, 25, 250, 1000 ng/kg bw/day) or PCB (0, 2, 20 μg/kg bw/day) alone, or in combination with each concentration of both compounds. Incorrect concentrations were published in a previous abstract. The test substance was mixed with corn oil and given by gavage at 2 ml/kg daily for 28 days. At the end of the experiment, the rats were killed and liver samples were prepared for transmission electron microscopy.

scholarly journals An Estimate of Reflection Coefficients for Rabbit Heart Capillaries

1964 ◽  
Vol 47 (4) ◽  
pp. 667-677 ◽  
Author(s):  
Fernando Vargas ◽  
John A. Johnson
Keyword(s):  
Weight Change ◽  
Rabbit Heart ◽  
Ringer Solution ◽  
Reflection Coefficients ◽  
Test Substance ◽  
Time Rate ◽  
Loss Of Weight ◽  
Test Molecule ◽  
Zero Time ◽  
Heart Capillaries

Isolated perfused rabbit hearts have been used to determine the reflection coefficients, σ, of the heart capillaries to certain lipoid-insoluble substances. This was done by initially perfusing the heart with a Ringer solution containing no test molecule and then suddenly switching to a solution which differed from the original only by containing a small amount of test substance. This produced a loss of weight of the heart which was continuously recorded as a function of time. Taking the "zero" time rate of weight change and using an equation given by Kedem and Katchalsky reflection coefficients for urea, sucrose, raffinose, and inulin were obtained. These turned out to be 0.1, 0.3, 0.38, and 0.69 respectively. Using the approach of Durbin and Solomon equivalent pore radii were estimated to be about 35 Angstroms.

Mouse Skin Bioassay for Chemical Carcinogens

1982 ◽  
Vol 1 (1) ◽  
pp. 47-82 ◽  
Author(s):  
Michael A. Pereira
Keyword(s):  
Aromatic Hydrocarbons ◽  
Environmental Samples ◽  
Alkylating Agents ◽  
Mouse Skin ◽  
Test Substance ◽  
Review Of The Literature ◽  
Carcinogenic Activity ◽  
Tier Ii ◽  
Direct Acting ◽  
Halogenated Methanes

The mouse skin initiation/promotion bioassay is one of the proposed bioassays of the Carcinogenesis Testing Matrix for tier II (Bull and Pereira, 1980). A review of the literature indicated that 544 chemicals and substances have been examined by application to mouse skin for carcinogenic activity. Poly-cyclic aromatic hydrocarbons, direct acting alkylating agents, and environmental samples of complex mixtures and subtractions of them that include condensates of automobile exhaust and cigarette smoke have been demonstrated to be carcinogenic by the mouse skin bioassay. Chemical classes of carcinogens that have not been demonstrated to contain initiation and carcinogens in mouse skin include azoxy, diazo, halogenated methanes, hydrazine, inorganics, steroids, and sulfonates. The mouse skin assay can be modified so mat the test substance is administered systemically i.e., oral and intraperitoneal and the promoter applied topically. This modification has the potential of increasing the number of chemical classes detected in the mouse skin initiation/promotion bioassay.

THE BENIGN EFFECTS ON RABBITS' LUNGS OF THE ASPIRATION OF WATER COMPARED WITH 5% GLUCOSE OR MILK

PEDIATRICS ◽  
1970 ◽  
Vol 46 (4) ◽  
pp. 538-547
Author(s):  
Mary Olson
Keyword(s):  
Blood Gases ◽  
Test Substance ◽  
Polyethylene Tube ◽  
Lung Volumes ◽  
First Feeding ◽  
Glucose Water

A 5% solution of glucose in water is often used for the first feeding, on the assumption that if aspirated it would be less injurious to lungs than milk. We have tested that assumption on 56 rabbits, divided into seven groups, anesthetized, and intubated with a polyethylene tube. They were sacrificed at 15 minutes or 24 hours after the instillation of 5% glucose, water, on milk. Comparisons of the treated groups with one group of control rabbits were made with respect to blood gases, resting lung volumes, lung weights, pressure-volume curves, and histology. The results showed no significant differences between milk and 5% glucose by any criterion at 15 minutes or 24 hours. The water-treated rabbits had significantly less damage to their lungs. This suggests that water would be a safer test substance for the first feed than 5% glucose or milk.

EXPRESS METHOD FOR DETERMINING OF IODINE NUMBER IN FATS AND OILS

2019 ◽  
Author(s):  
В.И. МАРТОВЩУК ◽  
Е.В. МАРТОВЩУК ◽  
А.А. ЛОБАНОВ ◽  
И.В. РЫБАНЧУК ◽  
Ю.Ш. ЮСУПОВА
Keyword(s):  
Iodine Number ◽  
Rapid Determination ◽  
Sodium Thiosulfate ◽  
Fats And Oils ◽  
Alcoholic Solution ◽  
Test Substance ◽  
Blue Color ◽  
Express Method ◽  
Excess Iodine

Разработан экспресс-метод определения йодного числа в жирах и маслах, исключающий применение агрессивных и токсичных реагентов и значительно сокращающий длительность измерения. Разработанный метод позволяет определить показатель степени непредельности жиров и масел, жиросодержащих пищевых продуктов. Методика предусматривает предварительную обработку масел в МХА. Затем навеску исследуемого вещества от 0,03 до 0,05 г, взятую с точностью до ± 0,0002 г, помещают в сухую коническую колбу с притертой пробкой. В колбу вносят 10 см3спирто-эфирной смеси (1 : 1), тщательно перемешивают. Затем к навеске добавляют 30 см3 спиртового раствора йода концентрацией 0,1 моль/дм3, перемешивают. Приливают 100 см3 дистиллированной воды. Колбу закрывают пробкой, встряхивают и выдерживают в темноте 20 мин. Избыточный йод оттитровывают раствором тиосульфата натрия концентрацией 0,1 моль/дм3. Перед окончанием титрования, когда раствор приобретет соломенно-желтый цвет, добавляют 1 см31%-го раствора крахмала и титруют до исчезновения синей окраски. Относительная погрешность определения йодного числа по разработанной методике невелика – от 0,141 до 0,149% при надежности 0,95. Разработанный метод рекомендован для оперативного определения йодных чисел масел и жиров в производственных и лабораторных условиях. Оперативность метода позволяет быстро вносить изменения в технологические процессы и обеспечивать стабильность производства и качества продукции. The express method of determination of iodine number in fats and oils, excluding the use of aggressive and toxic reagents and significantly reducing the duration of measurement, has been developed. The developed method allows define degree of unsaturated of the fats and oils containing fat of products. The technique involves the pretreatment of oils in a techno-chemical activator. Then the sample of the test substance from 0,03 to 0,05 g, taken with an accuracy of ± 0,0002 g, is placed in a dry conical flask with a ground glass stopper. In the flask make 10 cm3alcohol-ether mixture (1 : 1), mix sample thoroughly. Then add 30 cm3of an alcoholic solution of iodine with a concentration of 0,1 mol/dm3to the sample, mix. Then, pour 100 cm3of the distilled water. The flask is closed with a stopper, shaken and kept in the dark for 20 min. Excess iodine is titrated with a solution of sodium thiosulfate concentration of 0,1 mol/dm3. Before the end of titration, when the solution becomes straw yellow, add 1 cm3 of 1% starch solution and titrate until the blue color disappears. The relative error in the determination of the iodine number by the developed method is small – from 0,141 to 0,149% with a reliability of 0,95; that allows us to recommend the developed method for the rapid determination of iodine numbers of oils and fats in production and laboratory conditions. The efficiency of the method allows you to quickly make changes in technological processes and ensure the stability of production and product quality.

EVALUATION OF TOXIOLOGICAL INDICATORS OF MONTHMORRILLONITE CLAY FOR THE PURPOSE OF USING THEM AS ALUMOSILICATE SOBENT AGAINST THE NEGATIVE EFFECT OF MYCOTOXINS ON THE BODY OF ANIMALS AND BIRDS

2021 ◽  
Vol 1 (1) ◽  
pp. 72-78
Keyword(s):  
Experimental Studies ◽  
The Body ◽  
Montmorillonite Clay ◽  
Test Substance ◽  
Negative Effects ◽  
Experimental Animals ◽  
Eyelid Edema ◽  
White Rats ◽  
Mucous Membranes ◽  
Negative Effect

The article presents the results of laboratory studies to assess the toxicological parameters of montmorillonite clay from the Pogadaevskoye deposit in the West Kazakhstan region in order to use them as an aluminosilicate sorbent in the composition of feeds that reduce the negative effects of mycotoxins on the body of animals and birds. The relevance of research is associated with the cultivation of healthy and highly productive animals and poultry in order to ensure the food security of the Republic of Kazakhstan.The studies carried out to assess the toxicological parameters of montmorillonite clay in order to use them as an aluminosilicate sorbent in experimental animals (rabbits and white rats) allowed the following results to be obtained: Visual study of the intensity of erythema when exposed to the test substance on the skin of rabbits showed their absence (0 points). The study of the intensity of edema (an increase in the thickness of the skin clutch of rabbits) when exposed to the test substance on the skin of rabbits showed no reaction (0 points). Studies evaluating the irritating effect of the test substances on the mucous membranes of the eyes of rabbits by symptoms of damage showed the absence of hyperemia (0 points). Weak eyelid edema (1 point), the minimum amount of discharge in the corner of the eye (1 point). The results of studies on the classification assessment of the test substance for the severity of the irritant effect on the eyes of rabbits showed that the average total score of the severity of the irritative effect corresponds to 1 point. A comprehensive analysis of the results obtained on the basis of scientific and experimental studies to assess the toxicological indicators of montmorillonite clay from the Pogadaevskoye deposit in relation to irritating effects on the skin and mucous membranes of experimental animals (rabbits) showed their harmlessness.

Experimental Parameters Used to Study Pesticide Degradation in Soil

1996 ◽  
Vol 10 (1) ◽  
pp. 169-173 ◽  
Author(s):  
Michael R. Blumhorst
Keyword(s):  
Small Scale ◽  
Test Substance ◽  
Pesticide Degradation ◽  
Soil System ◽  
Experimental Parameters ◽  
Effective Cost ◽  
Cost Efficient ◽  
Efficient Mechanisms ◽  
Degradation In Soil

Characterization of pesticide degradation in soil is an important component in determining the environmental impact of agriculturally-applied pesticides. Several techniques currently are being used to generate these data, but small-scale laboratory studies remain one of the most effective, cost-efficient mechanisms of evaluating pesticide behavior in soil. With small-scale studies, many different environmental factors can be incorporated into the experimental design, and with the use of14C-labeled material, these studies (often referred to as soil degradation or soil metabolism studies) provide information on test substance persistence, degradation, volatilization, and mineralization. Care must be exercised, however, in selecting the experimental parameters to be used because of the potential adverse or artificial effects on the soil system.

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