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Mechery S, Narayanan Nair S, Divya TM, Promod K, Paramba SIN, Ravindran R, Juliet S. Influence of Pyrexia on Pharmacokinetics of Azithromycin and Its Interaction With Tolfenamic Acid in Goats. Front Vet Sci 2021; 8:675603. [PMID: 34179168 PMCID: PMC8222727 DOI: 10.3389/fvets.2021.675603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 04/27/2021] [Indexed: 11/13/2022] Open
Abstract
Azithromycin is a macrolide antimicrobial agent of the azalide group with a broad spectrum of activity against gram-negative and gram-positive bacterial organisms. Tolfenamic acid is a non-steroidal anti-inflammatory drug of the fenamate group, which is used extensively in humans and animals due to its anti-inflammatory, analgesic, and antipyretic properties. There is dearth of literature on any type of drug interaction between azithromycin and tolfenamic acid in any species, including human beings and alteration of its pharmacokinetics by fever. Therefore, the objective of this study was to investigate the alteration of disposition kinetics of azithromycin alone and in the presence of tolfenamic acid in Malabari goats by fever, following an intravenous administration at a dose rate of 20 mg/kg body weight. Blood samples collected from both afebrile and febrile goats at predetermined time intervals after the administration of azithromycin alone and then in combination with tolfenamic acid (2 mg/kg, intravenously), respectively, were analyzed using high-performance liquid chromatography. Non-compartmental analysis was used to determine the peak blood concentration (C max), time-to-peak plasma concentration (T max), half-life (t 1/2λz ), area under the curve (AUC 0-t, AUC 0-inf), area under the first moment curve (AUMC 0-inf), mean residence time (MRT0-inf), apparent volume of distribution at steady state (V ss), and the total body clearance of drug from the blood (Cl). In febrile animals, significant differences were noted in the values of C max, Cl, and V ss. Thus, azithromycin disappears into an additional compartment in febrile goats, which may be due to its extended cellular penetration into the inflammatory cells, resulting in anti-inflammatory activity. Tolfenamic acid significantly altered the pharmacokinetics of azithromycin in both normal and febrile animals. Tolfenamic acid, being a better anti-inflammatory agent, suppresses the inflammatory mediators, reducing the possibility of increased utilization of azithromycin in febrile condition.
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Affiliation(s)
- Sini Mechery
- Department of Veterinary Pharmacology and Toxicology, College of Veterinary and Animal Sciences, Pookode, Kerala Veterinary and Animal Sciences University, Wayanad, India
| | - Suresh Narayanan Nair
- Department of Veterinary Pharmacology and Toxicology, College of Veterinary and Animal Sciences, Pookode, Kerala Veterinary and Animal Sciences University, Wayanad, India
| | - Thirumangalath Meethal Divya
- Department of Veterinary Pharmacology and Toxicology, College of Veterinary and Animal Sciences, Pookode, Kerala Veterinary and Animal Sciences University, Wayanad, India
| | - Kanjirakuzhiyil Promod
- Department of Animal Reproduction Obstetrics and Gynaecology, College of Veterinary and Animal Sciences, Pookode, Kerala Veterinary and Animal Sciences University, Wayanad, India
| | - Sakkariya Ibrahim Nalukudy Paramba
- Department of Livestock Production Management, College of Veterinary and Animal Sciences, Pookode, Kerala Veterinary and Animal Sciences University, Wayanad, India
| | - Reghu Ravindran
- Department of Veterinary Parasitology, College of Veterinary and Animal Sciences, Pookode, Kerala Veterinary and Animal Sciences University, Wayanad, India
| | - Sanis Juliet
- Department of Veterinary Pharmacology and Toxicology, College of Veterinary and Animal Sciences, Pookode, Kerala Veterinary and Animal Sciences University, Wayanad, India
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Brown WE, Bradford BJ. Invited review: Mechanisms of hypophagia during disease. J Dairy Sci 2021; 104:9418-9436. [PMID: 34099296 DOI: 10.3168/jds.2021-20217] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 04/24/2021] [Indexed: 12/26/2022]
Abstract
Suppression of appetite, or hypophagia, is among the most recognizable effects of disease in livestock, with the potential to impair growth, reproduction, and lactation. The continued evolution of the field of immunology has led to a greater understanding of the immune and endocrine signaling networks underlying this conserved response to disease. Inflammatory mediators, especially including the cytokines tumor necrosis factor-α and interleukin-1β, are likely pivotal to disease-induced hypophagia, based on findings in both rodents and cattle. However, the specific mechanisms linking a cytokine surge to decreased feeding behavior are more difficult to pin down and likely include direct effects on appetite centers in the brain, alteration of gastric motility, and modulation of other endocrine factors that influence appetite and satiety. These insights into the mechanisms for disease-induced hypophagia have great relevance for management of neonatal calves, mature cows transitioning to lactation, and cows experiencing mastitis; however, it is not necessarily the case that increasing feed intake by any means possible will improve health outcomes for diseased cattle. We explore conflicting effects of hypophagia on immune responses, which may be impaired by the lack of specific substrates, versus apparent benefits for controlling the growth of some pathogens. Anti-inflammatory strategies have shown promise for promoting recovery of feed intake following some conditions but not others. Finally, we explore the potential for early disease detection through automated monitoring of feeding behavior and consider which strategies may be implemented to respond to early hypophagia.
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Affiliation(s)
- W E Brown
- Department of Animal Sciences & Industry, Kansas State University, Manhattan 66506
| | - B J Bradford
- Department of Animal Science, Michigan State University, East Lansing 48824.
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Rajput N, Dumka VK, Sandhu HS. Influence of experimentally induced fever on the disposition of cefpirome in buffalo calves. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2008; 26:305-308. [PMID: 21791379 DOI: 10.1016/j.etap.2008.06.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2008] [Revised: 06/02/2008] [Accepted: 06/10/2008] [Indexed: 05/31/2023]
Abstract
The influence of Escherichia coli endotoxin-induced fever on the disposition of cefpirome was investigated in five male buffalo calves following a single intravenous dose of 10mgkg(-1). Blood samples were collected from 1min to 24h of drug administration. The drug concentration in plasma was estimated by microbiological assay using E. coli as a test organism. The disposition of cefpirome followed two-compartment open model and the drug was detected above the minimum inhibitory concentration in plasma up to 12h. The Vd(area) and AUC were 0.75±0.01Lkg(-1) and 35.1±0.46μgml(-1)h, respectively. The elimination half-life of 1.81±0.009h and Cl(B) of 0.29±0.004Lkg(-1)h(-1) reflected rapid elimination and body clearance of cefpirome in febrile buffalo calves. Based on the results, a satisfactory dosage regimen of cefpirome in febrile buffalo calves was calculated to be 6mgkg(-1) to be repeated at 8h intervals.
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Affiliation(s)
- Neetu Rajput
- Department of Pharmacology and Toxicology, College of Veterinary Science, Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana 141004, India
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Affiliation(s)
- Geof W Smith
- Department of Population Health and Pathobiology, North Carolina State University, 4700 Hillsborough Street, Raleigh, NC 27606, USA.
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5
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Abstract
Many of the common gastrointestinal disorders of adult cattle may be diagnosed by a careful physical examination, whereas other disturbances require the use of diagnostic testing. It is important to differentiate the causes of gastrointestinal disturbances to make better treatment decisions and have a clearer prognosis for the specific animal or herd of cattle.
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Affiliation(s)
- E B Belknap
- Department of Large Animal Surgery and Medicine, Auburn University College of Veterinary Medicine, Alabama, USA
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6
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Chaudhary RK, Srivastava AK, Rampal S. Modification of the pharmacokinetics and dosage of cefuroxime by endotoxin-induced fever in buffalo calves. Vet Res Commun 1999; 23:361-8. [PMID: 10543365 DOI: 10.1023/a:1006385624850] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The effect of endotoxin-induced fever on the pharmacokinetics and dosage regimen of cefuroxime was investigated in buffalo calves following a single intravenous dose of 10 mg/kg body weight. The fever was induced by intravenous administration of E. coli endotoxin at a dose of 1 microg/kg body weight. The distribution and elimination half-lives were 0.100 h and 1.82 h, respectively, in healthy and 0.109 h and 2.28 h, respectively, in febrile buffalo calves. About 91% of the administered dose was excreted in the urine within 24 h. There was no effect of fever on the plasma protein binding of cefuroxime. The dosage regimen for intravenous administration of cefuroxime may be reduced in febrile conditions but the probability of this was only 0.3.
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Affiliation(s)
- R K Chaudhary
- Department of Pharmacology and Toxicology, College of Veterinary Science, Punjab Agricultural University, Ludhiana, India
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7
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van Miert AS, van Duin CT. Pharmacological and pathophysiological modulation of food intake and forestomach motility in small ruminants. J Vet Pharmacol Ther 1998; 21:1-17. [PMID: 9507452 DOI: 10.1046/j.1365-2885.1998.00101.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- A S van Miert
- Department of Veterinary Basic Sciences, Utrecht University, The Netherlands
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8
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Abstract
The objective of this study was to determine whether blockade of alpha(-2) adrenergic receptors would restore reticulorumen motility during toxaemia in cows. Reticulorumen contractions were measured via a water-filled balloon connected to a pressure transducer. Intravenous infusion of endotoxin (100 ng kg-1 over 30 min) significantly decreased the number of reticulorumen contractions. Intravenous infusion of yohimbine (125 micrograms kg-1 over 30 min) alone did not affect reticulorumen contractions. However, when yohimbine (125 micrograms kg-1 over 30 min) was infused concurrently with endotoxin (100 ng kg-1 over 30 min), the effects of endotoxin on reticulorumen contraction frequency decreased, suggesting that endotoxaemia causes reticulorumen stasis via a mechanism that involves alpha(-2) adrenergic receptors.
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Affiliation(s)
- S C Eades
- Department of Large Animal Medicine, College of Veterinary Medicine, University of Georgia, Athens 30602, USA
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van Miert AS. Pro-inflammatory cytokines in a ruminant model: pathophysiological, pharmacological, and therapeutic aspects. Vet Q 1995; 17:41-50. [PMID: 7571278 DOI: 10.1080/01652176.1995.9694530] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Infection evokes complex changes which are thought to be caused by production and release of pro-inflammatory cytokines such as tumour necrosis factor (TNF-alpha), interferons (INFs), and interleukins (ILs). They regulate local inflammatory reactions, but may also gain access to the circulation and induce systemic effects collectively known as the Acute Phase Response. To improve our understanding of the pathophysiology of pro-inflammatory cytokines in ruminants, studies have been performed with TNF-alpha, IL1-alpha/beta, and IFN-alpha/ gamma as well as with cytokine-inducers in dwarf goats. In relation to therapy, the following aspects may be of interest: a) Cytokine therapy given before or just after microbial challenge induces in vivo antimicrobial activity. Moreover, cytokines potentiate in vivo the antimicrobial activity of antibiotics, b) Cytokines may act as biological response modifiers for enhancing specific immunity to vaccines, and c) Cytokines may affect drug absorption, disposition, and metabolite formation in disease states. Although studies of the actions of corticosteroids, nonsteroidal anti-inflammatory and antipyretic agents, antibodies to endotoxin, TNF-alpha, or IL-1, synthetic E. coli lipid A precursors, hydrazine, isoniazid, chloroquine, polymyxin B, bicyclic imidazoles, hydroxamates, and tyrosine kinase inhibitors in endotoxaemic animals have shed further light on inflammatory processes, clinical studies in this field are urgently required to evaluate their beneficial effect.
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Affiliation(s)
- A S van Miert
- Department of Veterinary Basic Sciences, Utrecht University, The Netherlands
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Foley GL, Schlafer DH. Bacterial endotoxemia and reproductive effects in ruminants. Vet Clin North Am Food Anim Pract 1994; 10:491-501. [PMID: 7728632 DOI: 10.1016/s0749-0720(15)30534-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Gram-negative bacterial infections are fairly common in domestic ruminants. They can cause an endotoxemia with a variety of systemic signs, including fever, leukopenia, and ruminal stasis. Reproductive effects of endotoxemia include alterations in the estrous cycle and inability to maintain pregnancy. Diagnosis of endotoxemia is based largely on clinical evaluation. Confirming the diagnosis of endotoxin-induced reproductive alterations also is complicated by the lag period between clinical signs and abortion or infertility.
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Affiliation(s)
- G L Foley
- Department of Pathobiology, University of Illinois, Urbana
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11
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Aiumlamai S, Kindahl H, Fredriksson G, Edqvist LE, Kulander L, Eriksson Ö. The role of endotoxins in induced ruminal acidosis in calves. Acta Vet Scand 1992. [PMID: 1502995 DOI: 10.1186/bf03547318] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Experimentally induced ruminal acidosis was carried out in 4 calves to investigate the possibility of resorption of endotoxins from Gram negative bacteria originating from the gastro-intestinal tract. The ruminal acidosis was induced by overfeeding of oats and the effect was evaluated by clinical and blood biochemical changes. Blood samples were collected every 2 h for 60 h before and after experimental feeding. The animals showed signs of ruminal acidosis and also the clinical and blood biochemical changes were similar to those seen after experimental endotoxaemia. However, although being less dramatic the changes in many relevant parameters such as an increase in prostaglandin F metabolite levels, body temperature, endotoxins and a decrease in iron indicate that an endotoxaemic state had occurred. The results of the present study show that ruminal acidosis/stasis is linked to resorption of endotoxins from the gastro-intestinal tract causing endotoxaemia/endotoxicosis.
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The role of endotoxins in methscopolamine induced ruminal stasis in calves. Acta Vet Scand 1992. [PMID: 1502996 DOI: 10.1186/bf03547319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Methscopolamine was used to induce ruminal stasis in calves. Clinical and blood biochemical parameters were studied to judge the possible role of gastro-intestinal endotoxins from Gram-negative bacteria. Two trials were carried out where one injection of 100 mg and 3 consecutive injections of 70 mg of methscopolamine were administered. The animals showed signs of ruminal stasis. General clinical signs and changes in blood biochemical parameters were similar to what is found in endotoxaemia or in induced ruminal acidosis. Relevant parameters such as prostaglandin F2 alpha metabolite, endotoxin, iron, zinc, calcium and glutamate dehydrogenase changed significantly indicating exposure of endotoxins.
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13
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De Saedeleer V, Wechsung E, Houvenaghel A. Influence of indomethacin on endotoxin-induced changes in gastrointestinal myoelectrical activity and some haematological and clinical parameters in the conscious piglet. Vet Res Commun 1992; 16:59-67. [PMID: 1598755 DOI: 10.1007/bf01839205] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The effect of indomethacin, administered intravenously at 5 mg/kg, on the changes in gastrointestinal myoelectrical activity, rectal body temperature, clinical appearance and some haematological parameters induced by intravenous bolus injection of endotoxin, at 10 micrograms/kg, was examined in conscious piglets with electrodes implanted in the antrum pylori, duodenum, jejunum and ileum. Indomethacin inhibited the endotoxin-induced febrile response and the accompanying clinical signs. However, it was without influence on the induced leukopenia and shift to the left. Indomethacin both delayed the onset of and shortened the endotoxin-induced increase in the duration of the antral inhibitory phase and the duodenal phase I activity. It therefore appears that prostanoids are probably not the main factors involved in the endotoxin-induced haematological and gastrointestinal myoelectrical activity changes in the piglet.
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Affiliation(s)
- V De Saedeleer
- Laboratory of Veterinary Physiology, State University Centre, Antwerp, Belgium
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14
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Kisauzi DN, Leek BF. The effects of experimentally induced fever on the estimated blood flow to and oxygen utilization by the liver and the viscera drained by the portal vein in sheep. Vet Res Commun 1991; 15:95-105. [PMID: 2068799 DOI: 10.1007/bf00405141] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Intrajugular injection of a purified E. coli lipopolysaccharide induced a biphasic fever in sheep after a latent period of 12 to 20 min. The changes in the blood flow from the liver and from the viscera drained by the portal vein were: (a) in the latent period, decreases in total hepatic blood flow (THF) due to decreased portal venous blood flow (PVF); (b) during the first febrile phase, increases in THF due to increased hepatic arterial blood flow and, (c) in the second febrile phase, decreases in THF due to decreased PVF. Although there were large variations in the oxygen supply to the viscera drained by the portal vein and to the liver, there were relatively small or no changes in their oxygen consumption.
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Affiliation(s)
- D N Kisauzi
- Department of Physiology and Biochemistry, Veterinary College of Ireland, Dublin
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15
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van Miert AS, van Duin CT. Feed intake and rumen motility in dwarf goats. Effects of some alpha 2-adrenergic agonists, prostaglandins and posterior pituitary hormones. Vet Res Commun 1991; 15:57-67. [PMID: 1675505 DOI: 10.1007/bf00497791] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The purpose of the present investigation was to test the hypothesis that drug-induced changes in rumen contractions influence feed intake in dwarf goats. Intravenous (i.v.) administration of clonidine (1 microgram kg-1 min-1 for 10 min), xylazine (1 microgram kg-1 min-1 for 10 min), and PGF-2 alpha (10 micrograms kg-1 min-1 for 15 min) caused bradycardia and inhibition of rumen contractions. However, no appetite-stimulating effect of these drugs was observed. Other clinical changes induced by the alpha-adrenergic agonists included slight sedation and a decrease in body temperature; all clinical effects of clonidine and xylazine were partly antagonized by tolazoline pretreatment (10 micrograms kg-1 min-1 for 30 min). These results suggest that the CNS control of feeding differs in ruminants and monogastric species. In dwarf goats fasted for 2 h, i.v. administration of oxytocin (0.01 IU kg-1 min-1 for 15 min), vasopressin (0.01 IU kg-1 min-1 for 15 min), octapressin (0.003 IU kg-1 min-1 for 15 min) or PGE1 (0.8 microgram kg-1 min-1 for 15 min) did not change feeding behaviour during the two observation periods (0-30 min and 180-210 min after drug infusion, respectively). In previous studies, similar doses of these drugs induced changes in heart rate and inhibition of rumen contraction in goats. These findings demonstrate that drug-induced changes in forestomach contractions do not simply cause changes in feeding behaviour. The i.v. infusion of the PGF 2 alpha analogues etiproston (10 micrograms kg-1 min-1 for 15 min), luprostiol (30 micrograms kg-1 min-1 for 15 min), cloprostenol (1 microgram kg-1 min-1 for 15 min) and tiaprost (1 microgram kg-1 min-1 for 15 min) induced hypophagic effects and stimulated intestinal propulsion.
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Affiliation(s)
- A S van Miert
- Department of Veterinary Basic Sciences, Faculty of Veterinary Medicine, Utrecht University, The Netherlands
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King JN, Gerring EL. Antagonism of endotoxin-induced disruption of equine gastrointestinal motility with the platelet-activating factor antagonist WEB 2086. J Vet Pharmacol Ther 1990; 13:333-9. [PMID: 2287025 DOI: 10.1111/j.1365-2885.1990.tb00786.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The effect of pre-treatment with a selective platelet-activating factor (PAF) antagonist, WEB 2086, on the actions of low-dose endotoxin was evaluated in ponies prepared with gastrointestinal strain gauges. Endotoxin (0.1 microgram/kg i.v.) produced a marked reduction in gastric contraction amplitude and rate, and an increased frequency and reduced duration of jejunal phase III activity fronts (AFs). WEB 2086 (6.6 mg/kg) administered i.v. 10 min before the endotoxin, produced significant antagonism (P less than 0.001) of the effect of endotoxin on gastric contraction amplitude and rate. The combination of WEB 2086 and endotoxin produced gastric contractions of significantly (P less than 0.01) higher frequency than in the control studies. WEB 2086 also reduced endotoxin-induced abnormal phase III AFs in the jejunum and increases in heart rate and packed cell volume. These results provide evidence that endogenous PAF plays a role in mediating the acute effects of endotoxin on equine gastrointestinal motility.
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Affiliation(s)
- J N King
- Department of Surgery and Obstetrics, Royal Veterinary College, North Mymms, Herts, UK
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17
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van Miert AS, van Duin CT, Koot M. Effects of E. coli endotoxin, some interferon-inducers, recombinant interferon- alpha 2a and Trypanosoma brucei infection on feed intake in dwarf goats. J Vet Pharmacol Ther 1990; 13:327-31. [PMID: 2231875 DOI: 10.1111/j.1365-2885.1990.tb00784.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- A S van Miert
- Department of Veterinary Basic Sciences, Faculty of Veterinary Medicine, Utrecht University, The Netherlands
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Luthman J, Kindahl H, Jacobsson SO. The influence of flunixin on the response to Salmonella typhimurium endotoxin in calves. Acta Vet Scand 1990. [PMID: 2698058 DOI: 10.1186/bf03548034] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
The effects of intravenous injection of 0.5 microgram/kg body weight of Salmonella typhimurium endotoxin were studied in calves. The injection was followed by ruminal stasis and general dullness. The clinical signs disappeared within 24 hours. The injection was followed by a tremendous increase in the plasma level of 15-ketodihydro-PGF2 alpha, the main metabolite of PGF2 alpha. The injection was also associated with a profound leukopenia and significant decreases in the serum levels of iron, zinc and calcium. In order to study the role of prostaglandin (PG) for the development of endotoxin-induced changes a group of calves was pretreated with flunixin, a potent cyclo-oxygenase inhibitor, at a dose of 2.2 mg/kg body weight. Flunixin inhibited the PG release completely, but did not influence the other responses to endotoxin. The pyrogenic response to endotoxin was very moderate and it was suggested that fever is not the most suitable parameter for monitoring endotoxin effects in calves. The studied blood parameters (15-ketodihydro-PGF2 alpha, iron, zinc, calcium and the number of leukocytes) appeared to be much more sensitive.
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AIUMLAMAI S, FREDRIKSSON G, KINDAHL H, EDQVIST LE, KULANDER L, ERIKSSON Ö. Endotoxin concentrations in the blood following intravenous injection and effect on prostaglandin F2α release, calcium and bile acids in goats. Res Vet Sci 1990. [DOI: 10.1016/s0034-5288(18)30989-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Van Miert AS, Koot M, Van Duin CT. Appetite-modulating drugs in dwarf goats, with special emphasis on benzodiazepine-induced hyperphagia and its antagonism by flumazenil and RO 15-3505. J Vet Pharmacol Ther 1989; 12:147-56. [PMID: 2501511 DOI: 10.1111/j.1365-2885.1989.tb00656.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
In dwarf goats fasted for 2 h, i.v. administration of the benzodiazepine (BZ) agonists diazepam (60 micrograms/kg), brotizolam (2 and 4 micrograms/kg) and climazolam (100 micrograms/kg) induced hyperphagic effects, whereas i.v. injections of the BZ-antagonist flumazenil (R degrees 15-1788; 0.5 mg/kg), the anthelmintic ivermectin (0.1 mg/kg), the 5-HT2 antagonist ritanserine (0.1 mg/kg), ACTH (10 micrograms/kg) and prednisolone (1 mg/kg) were inactive in a 30-min feeding test. Both the BZ-antagonist R degrees 15-3505 (greater than or equal to 0.1 mg/kg) and the opiate receptor antagonist naloxone (0.1 mg/kg) had anorectic effects in dwarf goats given 30 min access to a palatable pelleted concentrate. The hyperphagic effects of climazolam and brotizolam were not antagonized by flumazenil, whereas similar doses of this drug completely reversed muscle incoordination and ataxia induced by much higher doses of these BZ-agonists. In the combination experiments with naloxone and BZ-agonists, naloxone antagonized the hyperphagic effects of both diazepam and brotizolam. Similarly, in the diazepam-R degrees 15-3505 study, there was a significant effect of diazepam and a significant inhibition of this effect by R degrees 15-3505 (50 micrograms/kg). In the diazepam-ivermectin combination experiment no evidence for drug potentiation was found. These results and the mode of action of the above mentioned drugs are discussed in relation to feeding behaviour.
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Affiliation(s)
- A S Van Miert
- Department of Veterinary Basic Sciences, Faculty of Veterinary Medicine, Utrecht University, The Netherlands
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