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1.
J. HENRI C. BUREL P. SANDERS & M. LAURENTIE 《Journal of veterinary pharmacology and therapeutics》2009,32(5):451-456
The pharmacokinetics of monensin including apparent volume of distribution, total body clearance, systemic bioavailability, partition coefficients and tissue residues were determined in chickens. The drug was given by intravenous injection in the left wing vein at the dose of 0.46 mg/kg and by intracrop administration at the dose of 4 mg/kg according to a destructive sampling. The pharmacokinetic variables were compared after noncompartmental, naïve averaged, naïve pooled and nonlinear mixed-effects modelling analyses. Partition coefficients and tissue residues were determined after a treatment with feed additives (125 mg/kg of feed) of 33 days. The clearance, volume of distribution and bioavailabilty were approximately 2.2 L/h/kg, approximately 9 L/kg and approximately 30% respectively except with nonlinear mixed effects models that presented values of 1.77 L/h/kg, 14.05 L/kg and 11.36% respectively. Tissue/plasma partition coefficients were estimated to 0.83, 3.39 and 0.51 for liver, fat and thigh muscle respectively. Monensin residues after treatment were not detected 6 h after withdrawal except for fat where monensin was still quantifiable 12 h after. Pharmacokinetic variables seem to be inaccurate when assessed with non linear mixed-effects modelling associated to destructive sampling in chickens. Values varied slightly with noncompartmental, naïve averaged and naïve pooled analyses. The absorption, elimination and partition parameters will be incorporated into a physiologically based pharmacokinetic model and the depletion study will be used to test the ability of this model to describe monensin residues in edible tissues under different dosage regimens. 相似文献
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Potassium depletion in cats: renal and dietary influences 总被引：1，自引：0，他引：1
S W Dow M J Fettman R A LeCouteur D W Hamar 《Journal of the American Veterinary Medical Association》1987,191(12):1569-1575
Excessive urinary potassium loss was diagnosed in 7 cats with persistent hypokalemia and high serum creatinine concentrations. Renal tubular acidosis (proximal or distal) was not evident in the affected cats. Plasma aldosterone concentrations and plasma renin activities in affected cats were not significantly different from control values. Potassium depletion and hypokalemia were attributed to the combined effects of decreased dietary potassium intake and excessive urinary potassium losses. It was concluded that increased urinary potassium excretion may represent a basic response to renal dysfunction in cats. Data suggested that dietary potassium supplementation improved renal function in most cats in this study. 相似文献
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Potassium depletion in cats: hypokalemic polymyopathy 总被引：1，自引：0，他引：1
S W Dow R A LeCouteur M J Fettman T L Spurgeon 《Journal of the American Veterinary Medical Association》1987,191(12):1563-1568
Generalized weakness of acute onset, apparent muscular pain, and persistent ventroflexion of the neck were observed in 6 cats. These clinical signs were associated with a low serum potassium concentration and high serum creatine kinase activity. Generalized electromyographic abnormalities, together with normal motor nerve conduction velocity determinations, were detected in all cats. Muscle biopsy specimens from 4 of 5 cats were not abnormal on light microscopic examination. Mild necrosis and infrequent macrophages were evident in a muscle biopsy specimen from one cat. Signs of polymyopathy resolved in all cats, and creatine kinase activities returned to the normal range after parenteral and oral administration of potassium. Polymyopathy and hypokalemia recurred in 3 cats in which dietary potassium supplementation was not maintained after initial recovery from hypokalemic polymyopathy. 相似文献
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K E Kopecky 《Journal of the American Veterinary Medical Association》1978,173(6):729-733
Man has inadvertently modified the stratosphere. There is a good possibility that the ozone layer is being depleted by the use of jet aircraft (SST), chlorofluoromethane propellants, and nitrogen fertilizers. Under unpolluted conditions, the production of ozone equals its destruction. By man's intervention, however, the destruction may exceed the production. The potential outcome is increased intensity of solar ultraviolet (280-400 nm) radiation and penetration to the earth's surface of previously absorbed wavelengths below about 280 nm. The increased ultraviolet radiation would increase the likelihood of skin cancer in man and ocular squamous cell carcinoma in cattle. The climate also might be modified, possibly in an undesirable way. 相似文献
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R F Slocombe J Malark R Ingersoll F J Derksen N E Robinson 《American journal of veterinary research》1986,47(10):2313-2317
Twenty-six Holstein calves were treated with hydroxyurea in order to induce neutropenia. Calves were given a daily dosage of hydroxyurea (70 mg/kg of body weight) for 4 consecutive days, and clinical signs, blood leukograms, hemograms, and platelet counts were monitored daily until the calves became neutropenic. Once a neutropenic state was induced, the calves were anesthetized and pulmonary function tests were performed. Subsequently, calves were euthanatized and complete necropsies were performed. Hydroxyurea treatment induced profound neutropenia in all calves by 8 days after initiating treatment, with mild decreases in circulating numbers of lymphocytes. Treatment did not cause clinical or pulmonary functional abnormalities. Severe pathologic changes were restricted to the bone marrow and consisted of partial to complete destruction of myeloid elements, with less severe effects on erythrocytic precursors and megakaryocytes. Hydroxyurea was useful for the induction of neutropenic states in calves and did not induce major toxic effects on other cells when given at 70 mg/kg. 相似文献
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P. Suknikom U. Jermnak S. Poapolathep S. Isariyodom M. Giorgi S. Kumagai A. Poapolathep 《Journal of veterinary pharmacology and therapeutics》2016,39(1):90-94
To evaluate the toxicokinetics and persistence of residues of melamine (MEL) in ducks, MEL was administered intravenously (i.v.) or orally (p.o.) to ducks at a dosage of 5.5 mg/kg body weight. The concentration of MEL in the plasma and various tissues was detected using HPLC equipped with an ultraviolet detector. The plasma concentration of MEL in ducks was determined up to 12 h after both i.v. and p.o. administrations. The average value of elimination half‐life (t1/2β) of MEL was 2.16 ± 0.37 and 2.01 ± 0.56 h after i.v. and p.o. administration, respectively. The absolute p.o. bioavailability was 90.79%. MEL was measurable in the liver and kidney after p.o. administration with maximum levels of 15.80 ± 1.81 and 15.49 ± 2.12 μg/g at 6 h, respectively. The results suggest that most of the administered MEL is efficiently absorbed from the gastro intestinal tract, and it has the ability to distribute into various tissues of the duck. 相似文献
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S J Mayer 《The Veterinary record》1992,131(6):120-122
There is an increasing concern over ozone depletion and its effects on the environment and human health. However, the increase in ultraviolet-B radiation (UV-B) that would result from significant losses of ozone is also potentially harmful to animals. Any increase in disease in domestic species would not only have serious animal welfare implications but may also be economically important. The diseases which are likely to increase if ozone depletion continues include the squamous cell carcinomas of the exposed, non-pigmented areas of cats, cattle, sheep and horses. Uberreiter's syndrome in dogs is also associated with exposure to UV-B and may be expected to increase, as may the severity of conditions such as infectious keratoconjunctivitis (New Forest eye) in cattle. Aquaculture systems in which fish often have little or no protection by shading may also be at risk. Cataracts and skin lesions have been associated with the exposure of farmed fish to ultraviolet radiation and have resulted in significant losses. 相似文献
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Oxytetracycline pharmacokinetics, tissue depletion, and toxicity after administration of a long-acting preparation at double the label dosage 总被引：1，自引：0，他引：1
Oxytetracycline (OTC) concentration in plasma and tissues, plasma pharmacokinetics, depletion from tissue, and toxicity were studied in 30 healthy calves after IM administration of a long-acting OTC preparation (40 mg/kg of body weight) at double the label dosage (20 mg/kg). Plasma OTC concentration increased rapidly after drug administration, and by 2 hours, mean (+/- SD) values were 7.4 +/- 2.6 micrograms/ml, Peak plasma OTC concentration was 9.6 +/- 2.6 micrograms/ml, and the time to peak plasma concentration was 7.6 +/- 4.0 hours. Plasma OTC concentration decreased slowly for 168 hours (elimination phase) after drug administration, and the elimination half-life was 23.9 hours. Plasma OTC concentration exceeded 3.8 micrograms/ml at 48 hours after drug administration. From 168 to 240 hours after drug administration, plasma OTC concentration decreased at a slower rate than that seen during the elimination phase. This slower phase was termed the depletion phase, and the depletion half-life was 280.7 hours. Tissue OTC concentration was highest in kidneys and liver. Lung OTC concentration exceeded 4.4 micrograms/g of tissue and 2.0 micrograms/g of tissue at 12 and 48 hours after drug administration, respectively. The drug persisted the longest in kidneys and liver. At 42 days after drug administration, 0.1 micrograms of OTC/g of kidney was detected. At 49 days after drug administration, all OTC tissue concentrations were below the detectable limit. Reactions and toxicosis after drug administration were limited to an anaphylaxis-like reaction (n = 1) and injection site swellings (n = 2). 相似文献
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P J Johnson T E Goetz J H Foreman R S Vogel W E Hoffmann G J Baker 《American journal of veterinary research》1991,52(10):1676-1683
The effects of whole-body potassium depletion induced by food deprivation on plasma, erythrocyte, and middle gluteal muscle K concentrations was quantified in 16 healthy, adult horses before, during, and at the end of a 7-day period of food deprivation during which water and sodium chloride were available ad libitum. Potassium concentrations were determined by atomic absorption spectroscopy. Plasma K concentration remained constant (3.49 +/- 0.09 mM K/L of plasma; mean +/- SEM) throughout the study. Erythrocyte potassium concentration decreased from 93.10 +/- 1.94 mM K/L of erythrocytes on day 0 to 88.63 +/- 2.39 mM K/L of erythrocytes on day 2 (decrease of 4.8%; P less than 0.05) and thereafter did not change. The K concentration of the middle gluteal muscle decreased from 91.06 +/- 2.96 microM K/g of muscle (wet weight) to 79.61 +/- 2.09 microM K/g of muscle (decrease of 12.6%; P less than 0.05) on day 4 and decreased further on day 7 to 73.62 +/- 1.85 microM K/g of muscle (decrease of 19.2%; P less than 0.05). There was no correlation between the plasma and erythrocyte K concentrations (r = -0.066), the erythrocyte and middle gluteal muscle K concentrations (r = 0.167), or the plasma and middle gluteal muscle potassium concentrations (r = -0.018). The water content of the middle gluteal muscle remained constant (73.23 +/- 0.36%) throughout the study. Erythrocyte membrane potential did not change (-99.26 +/- 0.87 mV) during the study, whereas the magnitude of the membrane potential of the middle gluteal muscle decreased from -105.84 +/- 1.67 mV on day 0 to -100.93 +/- 2.10 mV on day 7 (P less than 0.05). 相似文献
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Chiesa OA Li H Kijak PJ Li JX Lancaster V Smith ML Heller DN Thomas MH Von Bredow J 《Journal of veterinary pharmacology and therapeutics》2012,35(3):249-258
Sulfonamides are among the oldest, but still effective, antimicrobial veterinary medicines. In steers and dairy cows, the sulfonamides are effective in the treatment of respiratory disease and general infections. Sulfadimethoxine (SDM) has been approved by US Food and Drug Administration (FDA) for use in steers and dairy cows with a tolerance of 100 ng/g (ppb) in edible tissues and 10 ppb in milk. The detection of SDM residue above tolerance in the animal slaughtered for food process will result in the whole carcass being discarded. This report describes a comprehensive depletion study of SDM (and its main metabolite) in plasma, urine, oral fluid, kidney, and liver. In this study, nine steers were injected intravenously with the approved dose of SDM; the loading dose was 55 mg/kg, followed by 27.5 mg/kg dose at 24 h and again at 48 h. Fluids (blood, urine, and saliva) and tissue (liver and kidney) samples were collected at intervals after the last dose of SMD. The combination of laparoscopic serial sampling technique with the liquid chromatography/mass spectrometry method provided the data to establish the tissue/fluid correlation in the depletion of SMD. A strong correlation and linearity of the log-scale concentration over time in the depletion stage has been confirmed for kidney, liver, and plasma. 相似文献
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1. A physiologically-based pharmacokinetic model was developed for the purpose of describing the relationship between plasma concentration of drugs and their deposition into eggs. 2. By incorporating the physiology of egg formation into the model, the transfer of drugs into the egg albumen and yolk could be described using rate constants. 3. The model was used to describe concentrations in albumen and yolk of sulphanilamide, sulphaquinoxaline and pyrimethamine as a function of time using datasets from the literature. 4. The model could be used as a tool to obtain an insight into those properties of a drug which are responsible for the amount of residue in eggs, and could help in the design of critical studies for determining withdrawal periods for eggs. 相似文献
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M. Zhao K.‐Z. Xie H.‐S. Guo A.‐H. Li X. Xie G.‐X. Zhang G.‐J. Dai J.‐Y. Wang 《Journal of veterinary pharmacology and therapeutics》2015,38(5):508-512
A residue depletion study of ampicillin (AMP) was performed after oral dosing (60.0 mg/kg and 120.0 mg/kg body weight once a day for 5 days) to laying hens, through the use of reversed‐phase high‐performance liquid chromatography with fluorescence detection (RP‐HPLC‐FLD) to achieve detection of ampicillin residue in eggs. Limit of detection was 0.5 ng/g, and limit of quantitation was 1.2 ng/g for ampicillin. Extraction recoveries of ampicillin from samples fortified at 5.0–125.0 ng/g levels ranged from 77.5% to 84.6% in albumen, 77.9% to 87.5% in yolk, and 77.9% to 88.6% in whole egg, with coefficients of variation ≤9.3%. The maximum concentrations of ampicillin in albumen, yolk, and whole egg were detected at 1, 2, and 1 day after the last administration of ampicillin, respectively. Ampicillin was not detectable in albumen at day 9 of withdrawal time, at day 10 and 11 in yolk, and day 9 and 11 in whole egg at each of those 2 dose levels. The theoretical withdrawal time of AMP in whole egg was 6.730 and 7.296 days for 60 and 120 mg/kg oral dosage, respectively. This method also proved to be suitable as a rapid and reliable method for the determination of ampicillin in other poultry eggs. 相似文献
19.
Dietary exposure assessment of cyadox based on tissue depletion of cyadox and its major metabolites in pigs,chickens, and carp 
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下载免费PDF全文 L. L. Huang Y. M. Qiu L. L. Sun J. Li Y. H. Pan Y. L. Wang Z. H. Yuan 《Journal of veterinary pharmacology and therapeutics》2018,41(1):125-136
The tissue kinetics of cyadox, an antibacterial agent used in food animals, and its major metabolites in pigs, chickens, and carp were investigated followed by a complete dietary exposure assessment to evaluate the food safety of cyadox. Cyadox and its major metabolites, bisdeoxycyadox (Cy1), 4‐desoxycyadox (Cy2), N ‐(quinoxaline‐2‐methyl)‐cyanide acetyl hydrazine (Cy4), quinoxaline‐2‐carboxylic acid (Cy6), and 2‐hydromethyl‐3‐hydroxy‐quinoxaline (Cy12), were simultaneously quantitated with a high‐performance liquid chromatography?ultraviolet (HPLC ‐UV ) method. Pigs, chickens, and carp were fed with 150 mg/kg cyadox in feed for consecutive 60, 40, and 30 days, respectively. The residue amount of cyadox and its major metabolites in liver, kidney, muscle, and fat (skin) tissues was determined. Cy2 was below the limit of quantitation even at the withdrawal time of 6 hr, cyadox, Cy4, Cy6, and Cy12 could be detected at 6–24 hr with low level less than 50 μg/kg. By contrast, Cy1 persisted for 3 days in the kidney of pigs and chickens, and in the liver of carp. Based on these residue depletion data and previous toxicology results, the global estimated chronic dietary exposure assessment of cyadox for general population was conducted, indicating a zero withdrawal time (WDT ) may be appropriate for cyadox in food animals when used in feed for prolonged administration. These results provide analytical techniques and safety standards suitable for residue monitoring of cyadox in food animals. 相似文献
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The vitamin E distribution in serum, liver, adipose and muscle tissues in the pig during depletion and repletion 总被引：1，自引：0，他引：1
This study was designed to examine the storage capacity for vitamin E in liver, adipose tissue and skeletal muscle of growing pigs during a period of supplementation and of depletion. Therefore, biopsy specimens of these tissues and samples of serum were frequently taken from 7 pigs throughout the experimental period. After a 7-week period on a diet highly supplemented with vitamin E (405 mg/kg), a significant increase (p less than 0.001) in the concentration of this vitamin was observed in all tissues sampled. The highest level (102.9 +/- 26.2 mg/kg) was observed in the liver. After 2 days of depletion the concentration of vitamin E in the liver had fallen by 80%, whereas the concentration in the fat and muscle remained unchanged during 1 week of depletion. The serum vitamin E value rose significantly (p less than 0.001) after 1 week on the supplemented diet and then remained at about 7 mg/l throughout the supplementation period and decreased (p less than 0.001) after 2 days on a nonsupplemented diet. Generally, the serum vitamin E levels among growing pigs are between 2 and 3 mg/l. The results show that the serum and liver values were correlated when the serum level was within this range. Moreover, it is clearly demonstrated that the concentrations of vitamin E in serum and liver reflect the immediate nutritional status of the animal, whereas the vitamin concentrations in adipose and skeletal muscle tissue reflect its long-term nutritional history. 相似文献