<abstract xmlns="http://www.w3.org/1999/xhtml">

<sec id="j_jvetres-2018-0011_s_005">
<h3>Introduction</h3>
<p>The experiment evaluated the effects of intravenous administration of polymyxin B on experimental endotoxaemia in sheep.</p></sec>
<sec id="j_jvetres-2018-0011_s_006">
<h3>Material and Methods</h3>
<p>Twenty clinically healthy fat-tailed sheep were randomly divided into: a group treated with 6,000 U/kg of polymyxin B, a group at 12,000 U/kg, and positive and negative controls. Endotoxaemia was induced by intravenous administration of lipopolysaccharide (LPS) from <italic>E</italic>. <italic>coli</italic> serotype O55:B5 at 0.5 μg/kg. polymyxin was infused intravenously along with 2.5 L of isotonic intravenous fluids at 20 mL/kg/h. The positive control group received LPS and 2.5 L of isotonic fluids, the negatives receiving just 2.5 L of isotonic fluids. Clinical signs were evaluated before and at 1.5, 3, 4.5, 6, 24, and 48 h after LPS administration. Blood was also sampled at the denoted hours and serum haptoglobin, tumour necrosis factor-α (TNF-α), and plasma lactate concentrations were assayed.</p></sec>
<sec id="j_jvetres-2018-0011_s_007">
<h3>Results</h3>
<p>The serum concentration of TNF-α in the positive control group increased significantly up to 48 h after LPS administration. The concentration of TNF-α was significantly different from those of the polymyxin B and positive control groups from 3 to 48 h; also, the concentrations of haptoglobin at different times in the polymyxin groups were lower than those of the positive control group and were significant at hours 3 to 48 (P &lt; 0.05). Following the LPS administration, haptoglobin and TNF-α concentrations changed without significant difference between the two polymyxin B groups.</p></sec>
<sec id="j_jvetres-2018-0011_s_008">
<h3>Conclusion</h3>
<p>Polymyxin B (6,000 U/kg) restrained blood lactate concentrations. Furthermore, it significantly improved the clinical signs in endotoxaemic animals, including rectal temperature and heart and respiratory rates. Polymyxin B may be an antiendotoxic in fat-tailed sheep.</p></sec>
</abstract>

Introduction
The experiment evaluated the effects of intravenous administration of polymyxin B on experimental endotoxaemia in sheep.

Material and Methods
Twenty clinically healthy fat-tailed sheep were randomly divided into: a group treated with 6,000 U/kg of polymyxin B, a group at 12,000 U/kg, and positive and negative controls. Endotoxaemia was induced by intravenous administration of lipopolysaccharide (LPS) from E. coli serotype O55:B5 at 0.5 μg/kg. polymyxin was infused intravenously along with 2.5 L of isotonic intravenous fluids at 20 mL/kg/h. The positive control group received LPS and 2.5 L of isotonic fluids, the negatives receiving just 2.5 L of isotonic fluids. Clinical signs were evaluated before and at 1.5, 3, 4.5, 6, 24, and 48 h after LPS administration. Blood was also sampled at the denoted hours and serum haptoglobin, tumour necrosis factor-α (TNF-α), and plasma lactate concentrations were assayed.

Results
The serum concentration of TNF-α in the positive control group increased significantly up to 48 h after LPS administration. The concentration of TNF-α was significantly different from those of the polymyxin B and positive control groups from 3 to 48 h; also, the concentrations of haptoglobin at different times in the polymyxin groups were lower than those of the positive control group and were significant at hours 3 to 48 (P < 0.05). Following the LPS administration, haptoglobin and TNF-α concentrations changed without significant difference between the two polymyxin B groups.

Conclusion
Polymyxin B (6,000 U/kg) restrained blood lactate concentrations. Furthermore, it significantly improved the clinical signs in endotoxaemic animals, including rectal temperature and heart and respiratory rates. Polymyxin B may be an antiendotoxic in fat-tailed sheep.

Effects of polymyxin B on clinical signs, serum TNF-α, haptoglobin and plasma lactate concentrations in experimental endotoxaemia in sheep

Department of Clinical Sciences, School of Veterinary Medicine

Journal of Veterinary Research

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Introduction
The experiment evaluated the effects of intravenous administration of polymyxin B on experimental endotoxaemia in sheep.

Material and...

Effects of polymyxin B on clinical signs, serum TNF-α, haptoglobin and plasma lactate concentrations in experimental endotoxaemia in sheep

Published Online: Mar 30, 2018

Page range: 79 - 85

Received: Sep 18, 2017

Accepted: Feb 16, 2018

DOI: https://doi.org/10.2478/jvetres-2018-0011

Keywords
sheep, lipopolysaccharide, polymyxin B, clinical signs, inflammatory biomarkers

© 2018 A. Hajimohammadi et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Effects of polymyxin B on clinical signs, serum TNF-α, haptoglobin and plasma lactate concentrations in experimental endotoxaemia in sheep

Published Online: Mar 30, 2018

Page range: 79 - 85

Received: Sep 18, 2017

Accepted: Feb 16, 2018

DOI: https://doi.org/10.2478/jvetres-2018-0011

Keywordssheep, lipopolysaccharide, polymyxin B, clinical signs, inflammatory biomarkers

© 2018 A. Hajimohammadi et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Keywords
sheep, lipopolysaccharide, polymyxin B, clinical signs, inflammatory biomarkers